Contents
Top- Accessing and Updating Template Variables
- GET
- CALL
- SET
- DEFAULT
- Processing Template Files and Blocks
- INSERT
- INCLUDE
- PROCESS
- WRAPPER
- BLOCK
- Conditional Processing
- IF / UNLESS / ELSIF / ELSE
- SWITCH / CASE
- Loop Processing
- FOREACH
- WHILE
- Filters, Plugins, Macros and Perl
- FILTER
- USE
- MACRO
- PERL
- RAWPERL
- Exception Handling and Flow Control
- TRY / THROW / CATCH / FINAL
- NEXT
- LAST
- RETURN
- STOP
- CLEAR
- Miscellaneous
- META
- TAGS
- DEBUG
Accessing and Updating Template Variables
TopGET
Top
                          The GET directive retrieves and outputs the value of the
                          named variable.
                        
[% GET foo %]
                          The GET keyword is optional. A variable can be specified in
                          a directive tag by itself.
                        
[% foo %]
The variable can have an unlimited number of elements, each separated by a dot. Each element can have arguments specified within parentheses.
[% foo %] [% bar.baz %] [% biz.baz(10) %] ...etc...
See Template::Manual::Variables for a full discussion on template variables.
                          You can also specify expressions using the logical (and,
                          or, not, ?, :) and
                          mathematic operators (+, -, *,
                          /, %, mod, div).
                        
[% template.title or default.title %] [% score * 100 %] [% order.nitems ? checkout(order.total) : 'no items' %]
                          The div operator returns the integer result of division.
                          Both % and mod return the modulus (i.e.
                          remainder) of division.
                        
[% 15 / 6 %] # 2.5 [% 15 div 6 %] # 2 [% 15 mod 6 %] # 3
CALL
Top
                          The CALL directive is similar to GET in
                          evaluating the variable named, but doesn't print the result returned.
                          This can be useful when a variable is bound to a sub-routine or object
                          method which you want to call but aren't interested in the value
                          returned.
                        
[% CALL dbi.disconnect %] [% CALL inc_page_counter(page_count) %]
SET
Top
                          The SET directive allows you to assign new values to
                          existing variables or create new temporary variables.
                        
[% SET title = 'Hello World' %]
                          The SET keyword is also optional. [% title = 'Hello World'
                          %]
                        
                          Variables may be assigned the values of other variables, unquoted numbers
                          (2.718), literal text ('single quotes') or quoted text ("double quotes").
                          In the latter case, any variable references within the text will be
                          interpolated when the string is evaluated. Variables should be prefixed
                          by $, using curly braces to explicitly scope the variable
                          name where necessary.
                        
[% foo  = 'Foo'  %]               # literal value 'Foo'
[% bar  =  foo   %]               # value of variable 'foo'
[% cost = '$100' %]               # literal value '$100'
[% item = "$bar: ${cost}.00" %]   # value "Foo: $100.00"
                        Multiple variables may be assigned in the same directive and are evaluated in the order specified. Thus, the above could have been written:
[% foo  = 'Foo'
   bar  = foo
   cost = '$100'
   item = "$bar: ${cost}.00"
%]
                        
                          Simple expressions can also be used, as per GET.
                        
[% ten = 10 twenty = 20 thirty = twenty + ten forty = 2 * twenty fifty = 100 div 2 six = twenty mod 7 %]
                          You can concatenate strings together using the ' _ '
                          operator. In Perl 5, the . is used for string concatenation,
                          but in Perl 6, as in the Template Toolkit, the . will be
                          used as the method calling operator and ' _ ' will be used
                          for string concatenation. Note that the operator must be specified with
                          surrounding whitespace which, as Larry says, is construed as a feature:
                        
[% copyright = '(C) Copyright' _ year _ ' ' _ author %]
You can, of course, achieve a similar effect with double quoted string interpolation.
[% copyright = "(C) Copyright $year $author" %]
DEFAULT
Top
                          The DEFAULT directive is similar to SET but
                          only updates variables that are currently undefined or have no "true"
                          value (in the Perl sense).
                        
[% DEFAULT
    name = 'John Doe'
    id   = 'jdoe'
%]
                        This can be particularly useful in common template components to ensure that some sensible default are provided for otherwise undefined variables.
[% DEFAULT 
   title = 'Hello World'
   bgcol = '#ffffff'
%]
<html>
  <head>
    <title>[% title %]</title>
  </head>
  <body bgcolor="[% bgcol %]">
    ...etc...
                  Processing Template Files and Blocks
TopINSERT
Top
                          The INSERT directive is used to insert the contents of an
                          external file at the current position.
                        
[% INSERT myfile %]
No attempt to parse or process the file is made. The contents, possibly including any embedded template directives, are inserted intact.
                          The filename specified should be relative to one of the
                          INCLUDE_PATH directories. Absolute (i.e. starting with
                          /) and relative (i.e. starting with .)
                          filenames may be used if the ABSOLUTE and
                          RELATIVE options are set, respectively. Both these options
                          are disabled by default.
                        
my $template = Template->new({
    INCLUDE_PATH => '/here:/there',
});
$template->process('myfile');
                        myfile:
[% INSERT foo %] # looks for /here/foo then /there/foo [% INSERT /etc/passwd %] # file error: ABSOLUTE not set [% INSERT ../secret %] # file error: RELATIVE not set
For convenience, the filename does not need to be quoted as long as it contains only alphanumeric characters, underscores, dots or forward slashes. Names containing any other characters should be quoted.
[% INSERT misc/legalese.txt %] [% INSERT 'dos98/Program Files/stupid' %]
                          To evaluate a variable to specify a filename, you should explicitly
                          prefix it with a $ or use double-quoted string
                          interpolation.
                        
[% language = 'en' legalese = 'misc/legalese.txt' %] [% INSERT $legalese %] # misc/legalese.txt [% INSERT "$language/$legalese" %] # en/misc/legalese.txt
                          Multiple files can be specified using + as a delimiter. All
                          files should be unquoted names or quoted strings. Any variables should be
                          interpolated into double-quoted strings.
                        
[% INSERT legalese.txt + warning.txt %] [% INSERT "$legalese" + warning.txt %] # requires quoting
INCLUDE
Top
                          The INCLUDE directive is used to process and include the
                          output of another template file or block.
                        
[% INCLUDE header %]
                          If a BLOCK of the specified name is defined in the same
                          file, or in a file from which the current template has been called (i.e.
                          a parent template) then it will be used in preference to any file of the
                          same name.
                        
[% INCLUDE table %]     # uses BLOCK defined below
[% BLOCK table %]
   <table>
     ...
   </table>
[% END %]
                        
                          If a BLOCK definition is not currently visible then the
                          template name should be a file relative to one of the
                          INCLUDE_PATH directories, or an absolute or relative file
                          name if the ABSOLUTE/RELATIVE options are
                          appropriately enabled. The INCLUDE directive automatically
                          quotes the filename specified, as per INSERT described
                          above. When a variable contains the name of the template for the
                          INCLUDE directive, it should be explicitly prefixed by
                          $ or double-quoted
                        
[% myheader = 'my/misc/header' %] [% INCLUDE myheader %] # 'myheader' [% INCLUDE $myheader %] # 'my/misc/header' [% INCLUDE "$myheader" %] # 'my/misc/header'
Any template directives embedded within the file will be processed accordingly. All variables currently defined will be visible and accessible from within the included template.
[% title = 'Hello World' %] [% INCLUDE header %] <body> ...
header:
<html> <title>[% title %]</title>
output:
<html> <title>Hello World</title> <body> ...
Local variable definitions may be specified after the template name, temporarily masking any existing variables. Insignificant whitespace is ignored within directives so you can add variable definitions on the same line, the next line or split across several line with comments interspersed, if you prefer.
[% INCLUDE table %]
[% INCLUDE table title="Active Projects" %]
[% INCLUDE table 
     title   = "Active Projects" 
     bgcolor = "#80ff00"    # chartreuse
     border  = 2
%]
                        
                          The INCLUDE directive localises (i.e. copies) all variables
                          before processing the template. Any changes made within the included
                          template will not affect variables in the including template.
                        
[% foo = 10 %] foo is originally [% foo %] [% INCLUDE bar %] foo is still [% foo %] [% BLOCK bar %] foo was [% foo %] [% foo = 20 %] foo is now [% foo %] [% END %]
output:
foo is originally 10 foo was 10 foo is now 20 foo is still 10
                          Technical Note: the localisation of the stash (that is, the process by
                          which variables are copied before an INCLUDE to prevent
                          being overwritten) is only skin deep. The top-level variable namespace
                          (hash) is copied, but no attempt is made to perform a deep-copy of other
                          structures (hashes, arrays, objects, etc.) Therefore, a foo
                          variable referencing a hash will be copied to create a new
                          foo variable but which points to the same hash array. Thus,
                          if you update compound variables (e.g. foo.bar) then you
                          will change the original copy, regardless of any stash localisation. If
                          you're not worried about preserving variable values, or you trust the
                          templates you're including then you might prefer to use the
                          PROCESS directive which is faster by virtue of not
                          performing any localisation.
                        
                          You can specify dotted variables as "local" variables to an
                          INCLUDE directive. However, be aware that because of the
                          localisation issues explained above (if you skipped the previous
                          Technical Note above then you might want to go back and read it or skip
                          this section too), the variables might not actualy be "local". If the
                          first element of the variable name already references a hash array then
                          the variable update will affect the original variable.
                        
[% foo = {
       bar = 'Baz'
   }
%]
[% INCLUDE somefile foo.bar='Boz' %]
[% foo.bar %]           # Boz
                        
                          This behaviour can be a little unpredictable (and may well be improved
                          upon in a future version). If you know what you're doing with it and
                          you're sure that the variables in question are defined (nor not) as you
                          expect them to be, then you can rely on this feature to implement some
                          powerful "global" data sharing techniques. Otherwise, you might prefer to
                          steer well clear and always pass simple (undotted) variables as
                          parameters to INCLUDE and other similar directives.
                        
                          If you want to process several templates in one go then you can specify
                          each of their names (quoted or unquoted names only, no unquoted
                          $variables) joined together by +. The
                          INCLUDE directive will then process them in order.
                        
[% INCLUDE html/header + "site/$header" + site/menu
     title = "My Groovy Web Site"
%]
                        
                          The variable stash is localised once and then the templates specified are
                          processed in order, all within that same variable context. This makes it
                          slightly faster than specifying several separate INCLUDE
                          directives (because you only clone the variable stash once instead of n
                          times), but not quite as "safe" because any variable changes in the first
                          file will be visible in the second, third and so on. This might be what
                          you want, of course, but then again, it might not.
                        
PROCESS
Top
                          The PROCESS directive is similar to INCLUDE but does not
                          perform any localisation of variables before processing the template. Any
                          changes made to variables within the included template will be visible in
                          the including template.
                        
[% foo = 10 %] foo is [% foo %] [% PROCESS bar %] foo is [% foo %] [% BLOCK bar %] [% foo = 20 %] changed foo to [% foo %] [% END %]
output:
foo is 10 changed foo to 20 foo is 20
                          Parameters may be specified in the PROCESS directive, but
                          these too will become visible changes to current variable values.
                        
[% foo = 10 %] foo is [% foo %] [% PROCESS bar foo = 20 %] foo is [% foo %] [% BLOCK bar %] this is bar, foo is [% foo %] [% END %]
output:
foo is 10 this is bar, foo is 20 foo is 20
                          The PROCESS directive is slightly faster than
                          INCLUDE because it avoids the need to localise (i.e. copy)
                          the variable stash before processing the template. As with
                          INSERT and INCLUDE, the first parameter does
                          not need to be quoted as long as it contains only alphanumeric
                          characters, underscores, periods or forward slashes. A $
                          prefix can be used to explicitly indicate a variable which should be
                          interpolated to provide the template name:
                        
[% myheader = 'my/misc/header' %] [% PROCESS myheader %] # 'myheader' [% PROCESS $myheader %] # 'my/misc/header'
                          As with INCLUDE, multiple templates can be specified,
                          delimited by +, and are processed in order.
                        
[% PROCESS html/header + my/header %]
WRAPPER
TopIt's not unusual to find yourself adding common headers and footers to pages or sub-sections within a page. Something like this:
[% INCLUDE section/header title = 'Quantum Mechanics' %] Quantum mechanics is a very interesting subject wish should prove easy for the layman to fully comprehend. [% INCLUDE section/footer %] [% INCLUDE section/header title = 'Desktop Nuclear Fusion for under $50' %] This describes a simple device which generates significant sustainable electrical power from common tap water by process of nuclear fusion. [% INCLUDE section/footer %]
The individual template components being included might look like these:
section/header:
<p> <h2>[% title %]</h2>
section/footer:
</p>
                          The WRAPPER directive provides a way of simplifying this a
                          little. It encloses a block up to a matching END directive,
                          which is first processed to generate some output. This is then passed to
                          the named template file or BLOCK as the content
                          variable.
                        
[% WRAPPER section title = 'Quantum Mechanics' %] Quantum mechanics is a very interesting subject wish should prove easy for the layman to fully comprehend. [% END %] [% WRAPPER section title = 'Desktop Nuclear Fusion for under $50' %] This describes a simple device which generates significant sustainable electrical power from common tap water by process of nuclear fusion. [% END %]
The single 'section' template can then be defined as:
<h2>[% title %]</h2> <p> [% content %] </p>
Like other block directives, it can be used in side-effect notation:
[% INSERT legalese.txt WRAPPER big_bold_table %]
                          It's also possible to specify multiple templates to a
                          WRAPPER directive. The specification order indicates
                          outermost to innermost wrapper templates. For example, given the
                          following template block definitions:
                        
[% BLOCK bold %]<b>[% content %]</b>[% END %] [% BLOCK italic %]<i>[% content %]</i>[% END %]
the directive
[% WRAPPER bold+italic %]Hello World[% END %]
would generate the following output:
<b><i>Hello World</i></b>
BLOCK
Top
                          The BLOCK...END construct can be used to define
                          template component blocks which can be processed with the
                          INCLUDE, PROCESS and WRAPPER
                          directives.
                        
[% BLOCK tabrow %] <tr> <td>[% name %]<td> <td>[% email %]</td> </tr> [% END %] <table> [% PROCESS tabrow name='Fred' email='fred@nowhere.com' %] [% PROCESS tabrow name='Alan' email='alan@nowhere.com' %] </table>
                          A BLOCK definition can be used before it is defined, as long
                          as the definition resides in the same file. The block definition itself
                          does not generate any output.
                        
[% PROCESS tmpblk %] [% BLOCK tmpblk %] This is OK [% END %]
                          You can use an anonymous BLOCK to capture the output of a
                          template fragment.
                        
[% julius = BLOCK %] And Caesar's spirit, ranging for revenge, With Ate by his side come hot from hell, Shall in these confines with a monarch's voice Cry 'Havoc', and let slip the dogs of war; That this foul deed shall smell above the earth With carrion men, groaning for burial. [% END %]
                          Like a named block, it can contain any other template directives which
                          are processed when the block is defined. The output generated by the
                          block is then assigned to the variable julius.
                        
                          Anonymous BLOCKs can also be used to define block macros.
                          The enclosing block is processed each time the macro is called.
                        
[% MACRO locate BLOCK %] The [% animal %] sat on the [% place %]. [% END %] [% locate(animal='cat', place='mat') %] # The cat sat on the mat [% locate(animal='dog', place='log') %] # The dog sat on the log
Conditional Processing
TopIF / UNLESS / ELSIF / ELSE
Top
                          The IF and UNLESS directives can be used to
                          process or ignore a block based on some run-time condition.
                        
[% IF frames %] [% INCLUDE frameset %] [% END %] [% UNLESS text_mode %] [% INCLUDE biglogo %] [% END %]
                          Multiple conditions may be joined with ELSIF and/or
                          ELSE blocks.
                        
[% IF age < 10 %] Hello [% name %], does your mother know you're using her AOL account? [% ELSIF age < 18 %] Sorry, you're not old enough to enter (and too dumb to lie about your age) [% ELSE %] Welcome [% name %]. [% END %]
The following conditional and boolean operators may be used:
== != < <= > >= && || ! and or not
Conditions may be arbitrarily complex and are evaluated with the same precedence as in Perl. Parenthesis may be used to explicitly determine evaluation order.
# ridiculously contrived complex example [% IF (name == 'admin' || uid <= 0) && mode == 'debug' %] I'm confused. [% ELSIF more > less %] That's more or less correct. [% END %]
                          The and, or and not operator are
                          provided as aliases for &&, || and
                          !, respectively. Unlike Perl, which treats and,
                          or and not as separate, lower-precedence
                          versions of the other operators, the Template Toolkit performs a
                          straightforward substitution of and for
                          &&, and so on. That means that and,
                          or and not have the same operator precedence as
                          &&, || and !.
                        
SWITCH / CASE
Top
                          The SWITCH / CASE construct can be used to
                          perform a multi-way conditional test. The SWITCH directive
                          expects an expression which is first evaluated and then compared against
                          each CASE statement in turn. Each CASE directive should
                          contain a single value or a list of values which should match.
                          CASE may also be left blank or written as [% CASE
                          DEFAULT %] to specify a default match. Only one CASE
                          matches, there is no drop-through between CASE statements.
                        
[% SWITCH myvar %]
[%   CASE value1 %]
       ...
[%   CASE [ value2 value3 ] %]   # multiple values
       ...
[%   CASE myhash.keys %]         # ditto
       ...
[%   CASE %]                     # default
       ...
[% END %]
                  Loop Processing
TopFOREACH
Top
                          The FOREACH directive will iterate through the items in a
                          list, processing the enclosed block for each one.
                        
my $vars = {
    foo   => 'Foo',
    items => [ 'one', 'two', 'three' ],
};
template:
                        Things: [% FOREACH thing = [ foo 'Bar' "$foo Baz" ] %] * [% thing %] [% END %] Items: [% FOREACH i IN items %] * [% i %] [% END %] Stuff: [% stuff = [ foo "$foo Bar" ] %] [% FOREACH s IN stuff %] * [% s %] [% END %]
output:
Things: * Foo * Bar * Foo Baz Items: * one * two * three Stuff: * Foo * Foo Bar
                          You can use also use IN instead of = if you
                          prefer.
                        
[% FOREACH crook IN government %]
                          When the FOREACH directive is used without specifying a
                          target variable, any iterated values which are hash references will be
                          automatically imported.
                        
[% userlist = [
    { id => 'tom',   name => 'Thomas'  },
    { id => 'dick',  name => 'Richard'  },
    { id => 'larry', name => 'Lawrence' },
   ]
%]
[% FOREACH user IN userlist %]
   [% user.id %] [% user.name %]
[% END %]
                        short form:
[% FOREACH userlist %] [% id %] [% name %] [% END %]
                          Note that this particular usage creates a localised variable context to
                          prevent the imported hash keys from overwriting any existing variables.
                          The imported definitions and any other variables defined in such a
                          FOREACH loop will be lost at the end of the loop, when the
                          previous context and variable values are restored.
                        
                          However, under normal operation, the loop variable remains in scope after
                          the FOREACH loop has ended (caveat: overwriting any variable
                          previously in scope). This is useful as the loop variable is secretly an
                          iterator object (see below) and can be used to analyse the last entry
                          processed by the loop.
                        
                          The FOREACH directive can also be used to iterate through
                          the entries in a hash array. Each entry in the hash is returned in sorted
                          order (based on the key) as a hash array containing 'key' and 'value'
                          items.
                        
[% users = {
     tom   => 'Thomas',
     dick  => 'Richard',
     larry => 'Lawrence',
   }
%]
[% FOREACH u IN users %]
   * [% u.key %] : [% u.value %]
[% END %]
                        Output:
* dick : Richard * larry : Lawrence * tom : Thomas
                          The NEXT directive starts the next iteration in the
                          FOREACH loop.
                        
[% FOREACH user IN userlist %] [% NEXT IF user.isguest %] Name: [% user.name %] Email: [% user.email %] [% END %]
                          The LAST directive can be used to prematurely exit the loop.
                          BREAK is also provided as an alias for LAST.
                        
[% FOREACH match IN results.nsort('score').reverse %]
   [% LAST IF match.score < 50 %]
   [% match.score %] : [% match.url %]
[% END %]
                        
                          The FOREACH directive is implemented using the Template::Iterator module. A
                          reference to the iterator object for a FOREACH directive is
                          implicitly available in the loop variable. The following
                          methods can be called on the loop iterator.
                        
size() number of elements in the list max() index number of last element (size - 1) index() index of current iteration from 0 to max() count() iteration counter from 1 to size() (i.e. index() + 1) first() true if the current iteration is the first last() true if the current iteration is the last prev() return the previous item in the list next() return the next item in the list
See Template::Iterator for further details.
Example:
[% FOREACH item IN [ 'foo', 'bar', 'baz' ] -%] [%- "<ul>\n" IF loop.first %] <li>[% loop.count %]/[% loop.size %]: [% item %] [%- "</ul>\n" IF loop.last %] [% END %]
Output:
<ul> <li>1/3: foo <li>2/3: bar <li>3/3: baz </ul>
                          Nested loops will work as expected, with the loop variable
                          correctly referencing the innermost loop and being restored to any
                          previous value (i.e. an outer loop) at the end of the loop.
                        
[% FOREACH group IN grouplist;
     # loop => group iterator
     "Groups:\n" IF loop.first;
     FOREACH user IN group.userlist;
        # loop => user iterator
        "$loop.count: $user.name\n";
     END;
     # loop => group iterator
     "End of Groups\n" IF loop.last;
   END 
%]
                        
                          The iterator plugin can also be used to explicitly create an
                          iterator object. This can be useful within nested loops where you need to
                          keep a reference to the outer iterator within the inner loop. The
                          iterator plugin effectively allows you to create an iterator by a name
                          other than loop. See Template::Plugin::Iterator for further details.
                        
[% USE giter = iterator(grouplist) %]
[% FOREACH group IN giter %]
   [% FOREACH user IN group.userlist %]
         user #[% loop.count %] in
         group [% giter.count %] is
         named [% user.name %]
   [% END %]
[% END %]
                  WHILE
Top
                          The WHILE directive can be used to repeatedly process a
                          template block while a conditional expression evaluates true. The
                          expression may be arbitrarily complex as per IF /
                          UNLESS.
                        
[% WHILE total < 100 %] ... [% total = calculate_new_total %] [% END %]
An assignment can be enclosed in parenthesis to evaluate the assigned value.
[% WHILE (user = get_next_user_record) %] [% user.name %] [% END %]
                          The NEXT directive can be used to start the next iteration
                          of a WHILE loop and BREAK can be used to exit
                          the loop, both as per FOREACH.
                        
                          The Template Toolkit uses a failsafe counter to prevent runaway
                          WHILE loops which would otherwise never terminate. If the
                          loop exceeds 1000 iterations then an undef exception will be
                          thrown, reporting the error:
                        
WHILE loop terminated (> 1000 iterations)
                          The $Template::Directive::WHILE_MAX variable controls this
                          behaviour and can be set to a higher value if necessary.
                        
Filters, Plugins, Macros and Perl
TopFILTER
Top
                          The FILTER directive can be used to post-process the output
                          of a block. A number of standard filters are provided with the Template
                          Toolkit. The html filter, for example, escapes the '<',
                          '>' and '&' characters to prevent them from being interpreted as
                          HTML tags or entity reference markers.
                        
[% FILTER html %] HTML text may have < and > characters embedded which you want converted to the correct HTML entities. [% END %]
output:
HTML text may have < and > characters embedded which you want converted to the correct HTML entities.
                          The FILTER directive can also follow various other non-block
                          directives. For example:
                        
[% INCLUDE mytext FILTER html %]
                          The | character can also be used as an alias for
                          FILTER.
                        
[% INCLUDE mytext | html %]
Multiple filters can be chained together and will be called in sequence.
[% INCLUDE mytext FILTER html FILTER html_para %]
or
[% INCLUDE mytext | html | html_para %]
                          Filters come in two flavours, known as 'static' or 'dynamic'. A static
                          filter is a simple subroutine which accepts a text string as the only
                          argument and returns the modified text. The html filter is
                          an example of a static filter, implemented as:
                        
sub html_filter {
    my $text = shift;
    for ($text) {
        s/&/&/g;
        s/</</g;
        s/>/>/g;
    }
    return $text;
}
                        
                          Dynamic filters can accept arguments which are specified when the filter
                          is called from a template. The repeat filter is such an
                          example, accepting a numerical argument which specifies the number of
                          times that the input text should be repeated.
                        
[% FILTER repeat(3) %]blah [% END %]
output:
blah blah blah
                          These are implemented as filter 'factories'. The factory subroutine is
                          passed a reference to the current Template::Context object along
                          with any additional arguments specified. It should then return a
                          subroutine reference (e.g. a closure) which implements the filter. The
                          repeat filter factory is implemented like this:
                        
sub repeat_filter_factory {
    my ($context, $iter) = @_;
    $iter = 1 unless defined $iter;
    return sub {
        my $text = shift;
        $text = '' unless defined $text;
        return join('\n', $text) x $iter;
    }
}
                        
                          The FILTERS option, described in Template::Manual::Config,
                          allows custom filters to be defined when a Template object is
                          instantiated. The Template::Context#define_filter() method
                          allows further filters to be defined at any time.
                        
When using a filter, it is possible to assign an alias to it for further use. This is most useful for dynamic filters that you want to re-use with the same configuration.
[% FILTER echo = repeat(2) %] Is there anybody out there? [% END %] [% FILTER echo %] Mother, should I build a wall? [% END %]
Output:
Is there anybody out there? Is there anybody out there?
Mother, should I build a wall? Mother, should I build a wall?
                          The FILTER directive automatically quotes the name of the
                          filter. As with INCLUDE et al, you can use a variable to
                          provide the name of the filter, prefixed by $.
                        
[% myfilter = 'html' %] [% FILTER $myfilter %] # same as [% FILTER html %] ... [% END %]
A template variable can also be used to define a static filter subroutine. However, the Template Toolkit will automatically call any subroutine bound to a variable and use the value returned. Thus, the above example could be implemented as:
my $vars = {
    myfilter => sub { return 'html' },
};
                        template:
[% FILTER $myfilter %] # same as [% FILTER html %] ... [% END %]
                          To define a template variable that evaluates to a subroutine reference
                          that can be used by the FILTER directive, you should create
                          a subroutine that, when called automatically by the Template Toolkit,
                          returns another subroutine reference which can then be used to perform
                          the filter operation. Note that only static filters can be implemented in
                          this way.
                        
my $vars = {
    myfilter => sub { \&my_filter_sub },
};
sub my_filter_sub {
    my $text = shift;
    # do something
    return $text;
}
                        template:
[% FILTER $myfilter %] ... [% END %]
Alternately, you can bless a subroutine reference into a class (any class will do) to fool the Template Toolkit into thinking it's an object rather than a subroutine. This will then bypass the automatic "call-a-subroutine-to-return-a-value" magic.
my $vars = {
    myfilter => bless(\&my_filter_sub, 'anything_you_like'),
};
                        template:
[% FILTER $myfilter %] ... [% END %]
                          Filters bound to template variables remain local to the variable context
                          in which they are defined. That is, if you define a filter in a
                          PERL block within a template that is loaded via
                          INCLUDE, then the filter definition will only exist until
                          the end of that template when the stash is delocalised, restoring the
                          previous variable state. If you want to define a filter which persists
                          for the lifetime of the processor, or define additional dynamic filter
                          factories, then you can call the Template::Context#define_filter() method
                          on the current Template::Context object.
                        
See Template::Manual::Filters for a complete list of available filters, their descriptions and examples of use.
USE
Top
                          The USE directive can be used to load and initialise
                          "plugin" extension modules.
                        
[% USE myplugin %]
A plugin is a regular Perl module that conforms to a particular object-oriented interface, allowing it to be loaded into and used automatically by the Template Toolkit. For details of this interface and information on writing plugins, consult Template::Plugin.
A number of standard plugins are included with the Template Toolkit (see below and Template::Manual::Plugins). The names of these standard plugins are case insensitive.
[% USE CGI %] # => Template::Plugin::CGI [% USE Cgi %] # => Template::Plugin::CGI [% USE cgi %] # => Template::Plugin::CGI
                          You can also define further plugins using the PLUGINS
                          option.
                        
my $tt = Template->new({
    PLUGINS => {
        foo => 'My::Plugin::Foo',
        bar => 'My::Plugin::Bar',
    },
});
                        The recommended convention is to specify these plugin names in lower case. The Template Toolkit first looks for an exact case-sensitive match and then tries the lower case conversion of the name specified.
[% USE Foo %] # look for 'Foo' then 'foo'
                          If you define all your PLUGINS with lower case names then
                          they will be located regardless of how the user specifies the name in the
                          USE directive. If, on the other hand, you define your
                          PLUGINS with upper or mixed case names then the name
                          specified in the USE directive must match the case exactly.
                        
                          If the plugin isn't defined in either the standard plugins
                          ($Template::Plugins::STD_PLUGINS) or via the
                          PLUGINS option, then the PLUGIN_BASE is
                          searched.
                        
                          In this case the plugin name is case-sensitive. It is appended to
                          each of the PLUGIN_BASE module namespaces in turn (default:
                          Template::Plugin) to construct a full module name which it
                          attempts to locate and load. Any periods, '.', in the name
                          will be converted to '::'.
                        
[% USE MyPlugin %] # => Template::Plugin::MyPlugin [% USE Foo.Bar %] # => Template::Plugin::Foo::Bar
                          The LOAD_PERL option (disabled by default) provides a
                          further way by which external Perl modules may be loaded. If a regular
                          Perl module (i.e. not a Template::Plugin::* or other module
                          relative to some PLUGIN_BASE) supports an object-oriented
                          interface and a new() constructor then it can be loaded and
                          instantiated automatically. The following trivial example shows how the
                          IO::File module might be used.
                        
[% USE file = IO.File('/tmp/mydata') %]
[% WHILE (line = file.getline) %]
   <!-- [% line %] -->
[% END %]
                        
                          Any additional parameters supplied in parenthesis after the plugin name
                          will be also be passed to the new() constructor. A reference
                          to the current Template::Context object is passed as the first parameter.
                        
[% USE MyPlugin('foo', 123) %]
                        equivalent to:
Template::Plugin::MyPlugin->new($context, 'foo', 123);
                          The only exception to this is when a module is loaded via the
                          LOAD_PERL option. In this case the $context
                          reference is not passed to the new() constructor.
                          This is based on the assumption that the module is a regular Perl module
                          rather than a Template Toolkit plugin so isn't expecting a context
                          reference and wouldn't know what to do with it anyway.
                        
Named parameters may also be specified. These are collated into a hash which is passed by reference as the last parameter to the constructor, as per the general code calling interface.
[% USE url('/cgi-bin/foo', mode='submit', debug=1) %]
                        equivalent to:
Template::Plugin::URL->new(
    $context, 
    '/cgi-bin/foo'
    { mode => 'submit', debug => 1 }
);
                        The plugin may represent any data type; a simple variable, hash, list or code reference, but in the general case it will be an object reference. Methods can be called on the object (or the relevant members of the specific data type) in the usual way:
[% USE table(mydata, rows=3) %]
[% FOREACH row IN table.rows %]
   <tr>    
   [% FOREACH item IN row %]
    <td>[% item %]</td>
   [% END %]
   </tr>
[% END %]
                        An alternative name may be provided for the plugin by which it can be referenced:
[% USE scores = table(myscores, cols=5) %] [% FOREACH row IN scores.rows %] ... [% END %]
                          You can use this approach to create multiple plugin objects with
                          different configurations. This example shows how the Template::Plugin::Format plugin is used to
                          create sub-routines bound to variables for formatting text as per
                          printf().
                        
[% USE bold = format('<b>%s</b>') %]
[% USE ital = format('<i>%s</i>') %]
[% bold('This is bold')   %]
[% ital('This is italic') %]
                        Output:
<b>This is bold</b> <i>This is italic</i>
This next example shows how the Template::Plugin::URL plugin can be used to build dynamic URLs from a base part and optional query parameters.
[% USE mycgi = URL('/cgi-bin/foo.pl', debug=1) %]
<a href="[% mycgi %]">...
<a href="[% mycgi(mode='submit') %]"...
                        Output:
<a href="/cgi-bin/foo.pl?debug=1">... <a href="/cgi-bin/foo.pl?mode=submit&debug=1">...
                          The Template::Plugin::CGI plugin is
                          an example of one which delegates to another Perl module. In this this
                          case, to Lincoln Stein's CGI module. All of the methods
                          provided by the CGI module are available via the plugin.
                        
[% USE CGI;
   CGI.start_form;
   CGI.checkbox_group( name   = 'colours', 
                       values = [ 'red' 'green' 'blue' ] );
   CGI.popup_menu( name   = 'items', 
                   values = [ 'foo' 'bar' 'baz' ] );
   CGI.end_form 
%]
                        See Template::Manual::Plugins for more information on the plugins distributed with the toolkit or available from CPAN.
MACRO
Top
                          The MACRO directive allows you to define a directive or
                          directive block which is then evaluated each time the macro is called.
                        
[% MACRO header INCLUDE header %]
Calling the macro as:
[% header %]
is then equivalent to:
[% INCLUDE header %]
Macros can be passed named parameters when called. These values remain local to the macro.
[% header(title='Hello World') %]
equivalent to:
[% INCLUDE header title='Hello World' %]
                          A MACRO definition may include parameter names. Values
                          passed to the macros are then mapped to these local variables. Other
                          named parameters may follow these.
                        
[% MACRO header(title) INCLUDE header %]
[% header('Hello World') %]
[% header('Hello World', bgcol='#123456') %]
                        equivalent to:
[% INCLUDE header title='Hello World' %] [% INCLUDE header title='Hello World' bgcol='#123456' %]
Here's another example, defining a macro for display numbers in comma-delimited groups of 3, using the chunk and join virtual method.
[% MACRO number(n) GET n.chunk(-3).join(',') %]
[% number(1234567) %]    # 1,234,567
                        
                          A MACRO may precede any directive and must conform to the
                          structure of the directive.
                        
[% MACRO header IF frames %] [% INCLUDE frames/header %] [% ELSE %] [% INCLUDE header %] [% END %] [% header %]
                          A MACRO may also be defined as an anonymous
                          BLOCK. The block will be evaluated each time the macro is
                          called.
                        
[% MACRO header BLOCK %] ...content... [% END %] [% header %]
                          If you've got the EVAL_PERL option set, then you can even
                          define a MACRO as a PERL block (see below):
                        
[% MACRO triple(n) PERL %]
     my $n = $stash->get('n');
     print $n * 3;
[% END -%]
                  PERL
Top(for the advanced reader)
                          The PERL directive is used to mark the start of a block
                          which contains Perl code for evaluation. The EVAL_PERL
                          option must be enabled for Perl code to be evaluated or a
                          perl exception will be thrown with the message
                          'EVAL_PERL not set'.
                        
                          Perl code is evaluated in the Template::Perl package. The
                          $context package variable contains a reference to the
                          current Template::Context object. This can be used to access the
                          functionality of the Template Toolkit to process other templates, load
                          plugins, filters, etc. See Template::Context for further details.
                        
[% PERL %]
   print $context->include('myfile');
[% END %]
                        The $stash variable contains a reference to the top-level stash object which manages template variables. Through this, variable values can be retrieved and updated. See Template::Stash for further details.
[% PERL %]
   $stash->set(foo => 'bar');
   print "foo value: ", $stash->get('foo');
[% END %]
                        Output:
foo value: bar
                          Output is generated from the PERL block by calling
                          print(). Note that the Template::Perl::PERLOUT
                          handle is selected (tied to an output buffer) instead of
                          STDOUT.
                        
[% PERL %] print "foo\n"; # OK print PERLOUT "bar\n"; # OK, same as above print Template::Perl::PERLOUT "baz\n"; # OK, same as above print STDOUT "qux\n"; # WRONG! [% END %]
                          The PERL block may contain other template directives. These
                          are processed before the Perl code is evaluated.
                        
[% name = 'Fred Smith' %] [% PERL %] print "[% name %]\n"; [% END %]
Thus, the Perl code in the above example is evaluated as:
print "Fred Smith\n";
                          Exceptions may be thrown from within PERL blocks using
                          die(). They will be correctly caught by enclosing
                          TRY blocks.
                        
[% TRY %]
   [% PERL %]
      die "nothing to live for\n";
   [% END %]
[% CATCH %]
   error: [% error.info %]
[% END %]
                        output: error: nothing to live for
RAWPERL
Top(for the very advanced reader)
                          The Template Toolkit parser reads a source template and generates the
                          text of a Perl subroutine as output. It then uses eval() to
                          evaluate it into a subroutine reference. This subroutine is then called
                          to process the template, passing a reference to the current Template::Context object through
                          which the functionality of the Template Toolkit can be accessed. The
                          subroutine reference can be cached, allowing the template to be processed
                          repeatedly without requiring any further parsing.
                        
For example, a template such as:
[% PROCESS header %] The [% animal %] sat on the [% location %] [% PROCESS footer %]
is converted into the following Perl subroutine definition:
sub {
    my $context = shift;
    my $stash   = $context->stash;
    my $output  = '';
    my $error;
    eval { BLOCK: {
        $output .=  $context->process('header');
        $output .=  "The ";
        $output .=  $stash->get('animal');
        $output .=  " sat on the ";
        $output .=  $stash->get('location');
        $output .=  $context->process('footer');
        $output .=  "\n";
    } };
    if ($@) {
        $error = $context->catch($@, \$output);
        die $error unless $error->type eq 'return';
    }
    return $output;
}
                        
                          To examine the Perl code generated, such as in the above example, set the
                          $Template::Parser::DEBUG package variable to any true value.
                          You can also set the $Template::Directive::PRETTY variable
                          true to have the code formatted in a readable manner for human
                          consumption. The source code for each generated template subroutine will
                          be printed to STDERR on compilation (i.e. the first time a
                          template is used).
                        
$Template::Parser::DEBUG = 1;
$Template::Directive::PRETTY = 1;
$template->process($file, $vars)
    || die $template->error(), "\n";
                        
                          The PERL ... END construct allows Perl code to
                          be embedded into a template when the EVAL_PERL option is
                          set. It is evaluated at "runtime" using eval() each time the
                          template subroutine is called. This is inherently flexible, but not as
                          efficient as it could be, especially in a persistent server environment
                          where a template may be processed many times.
                        
                          The RAWPERL directive allows you to write Perl code that is
                          integrated directly into the generated Perl subroutine text. It is
                          evaluated once at compile time and is stored in cached form as part of
                          the compiled template subroutine. This makes RAWPERL blocks
                          more efficient than PERL blocks.
                        
                          The downside is that you must code much closer to the metal. For example,
                          in a PERL block you can call print() to generate some output.
                          RAWPERL blocks don't afford such luxury. The code is
                          inserted directly into the generated subroutine text and should conform
                          to the convention of appending to the $output variable.
                        
[% PROCESS header %] [% RAWPERL %] $output .= "Some output\n"; ... $output .= "Some more output\n"; [% END %]
The critical section of the generated subroutine for this example would then look something like:
...
eval { BLOCK: {
    $output .=  $context->process('header');
    $output .=  "\n";
    $output .= "Some output\n";
    ...
    $output .= "Some more output\n";
    $output .=  "\n";
} };
...
                        
                          As with PERL blocks, the Template::Context and Template::Stash references are pre-defined and
                          available for use within RAWPERL code.
                        
Exception Handling and Flow Control
TopTRY / THROW / CATCH / FINAL
Top(more advanced material)
                          The Template Toolkit supports fully functional, nested exception
                          handling. The TRY directive introduces an exception handling
                          scope which continues until the matching END directive. Any
                          errors that occur within that block will be caught and can be handled by
                          one of the CATCH blocks defined.
                        
[% TRY %] ...blah...blah... [% CALL somecode %] ...etc... [% INCLUDE someblock %] ...and so on... [% CATCH %] An error occurred! [% END %]
                          Errors are raised as exceptions (objects of the Template::Exception class)
                          which contain two fields: type and info. The
                          exception type is used to indicate the kind of error that
                          occurred. It is a simple text string which can contain letters, numbers,
                          '_' or '.'. The info field
                          contains an error message indicating what actually went wrong. Within a
                          catch block, the exception object is aliased to the error
                          variable. You can access the type and info
                          fields directly.
                        
[% mydsn = 'dbi:MySQL:foobar' %]
...
[% TRY %]
   [% USE DBI(mydsn) %]
[% CATCH %]
   ERROR! Type: [% error.type %]
          Info: [% error.info %]
[% END %]
                        
                          output (assuming a non-existant database called 'foobar'):
                        
ERROR!  Type: DBI
        Info: Unknown database "foobar"
                        
                          The error variable can also be specified by itself and will
                          return a string of the form "$type error - $info".
                        
... [% CATCH %] ERROR: [% error %] [% END %]
Output:
ERROR: DBI error - Unknown database "foobar"
                          Each CATCH block may be specified with a particular
                          exception type denoting the kind of error that it should catch. Multiple
                          CATCH blocks can be provided to handle different types of
                          exception that may be thrown in the TRY block. A
                          CATCH block specified without any type, as in the previous
                          example, is a default handler which will catch any otherwise uncaught
                          exceptions. This can also be specified as [% CATCH DEFAULT
                          %].
                        
[% TRY %] [% INCLUDE myfile %] [% USE DBI(mydsn) %] [% CALL somecode %] [% CATCH file %] File Error! [% error.info %] [% CATCH DBI %] [% INCLUDE database/error.html %] [% CATCH %] [% error %] [% END %]
                          Remember that you can specify multiple directives within a single tag,
                          each delimited by ';'. So the above example can be written
                          more concisely as:
                        
[% TRY;
       INCLUDE myfile;
       USE DBI(mydsn);
       CALL somecode;
   CATCH file;
       "File Error! $error.info";
   CATCH DBI;
       INCLUDE database/error.html;
   CATCH;
       error;
   END 
%]
                        
                          The DBI plugin throws exceptions of the DBI
                          type (in case that wasn't already obvious). The other specific exception
                          caught here is of the file type.
                        
                          A file exception is automatically thrown by the Template
                          Toolkit when it can't find a file, or fails to load, parse or process a
                          file that has been requested by an INCLUDE,
                          PROCESS, INSERT or WRAPPER
                          directive. If myfile can't be found in the example above,
                          the [% INCLUDE myfile %] directive will raise a
                          file exception which is then caught by the [% CATCH
                          file %] block. The output generated would be:
                        
File Error! myfile: not found
                          Note that the DEFAULT option (disabled by default) allows
                          you to specify a default file to be used any time a template file can't
                          be found. This will prevent file exceptions from ever being raised when a
                          non-existant file is requested (unless, of course, the
                          DEFAULT file your specify doesn't exist). Errors encountered
                          once the file has been found (i.e. read error, parse error) will be
                          raised as file exceptions as per usual.
                        
                          Uncaught exceptions (i.e. if the TRY block doesn't have a
                          type specific or default CATCH handler) may be caught by
                          enclosing TRY blocks which can be nested indefinitely across
                          multiple templates. If the error isn't caught at any level then
                          processing will stop and the Template Template#process() method will return a false
                          value to the caller. The relevant Template::Exception object can
                          be retrieved by calling the Template#error()
                          method.
                        
[% TRY %]
   ...
   [% TRY %]
      [% INCLUDE $user.header %]
   [% CATCH file %]
      [% INCLUDE header %]
   [% END %]
   ...
[% CATCH DBI %]
   [% INCLUDE database/error.html %]
[% END %]
                        
                          In this example, the inner TRY block is used to ensure that
                          the first INCLUDE directive works as expected. We're using a
                          variable to provide the name of the template we want to include,
                          user.header, and it's possible this contains the name of a
                          non-existant template, or perhaps one containing invalid template
                          directives. If the INCLUDE fails with a file
                          error then we CATCH it in the inner block and
                          INCLUDE the default header file instead. Any
                          DBI errors that occur within the scope of the outer
                          TRY block will be caught in the relevant CATCH
                          block, causing the database/error.html template to be
                          processed. Note that included templates inherit all currently defined
                          template variable so these error files can quite happily access the
                          <error> variable to retrieve information about the currently caught
                          exception. For example, the database/error.html template
                          might look like this:
                        
<h2>Database Error</h2> A database error has occurred: [% error.info %]
                          You can also specify a FINAL block. This is always processed
                          regardless of the outcome of the TRY and/or
                          CATCH blocks. If an exception is uncaught then the
                          FINAL block is processed before jumping to the enclosing
                          block or returning to the caller.
                        
[% TRY %] ... [% CATCH this %] ... [% CATCH that %] ... [% FINAL %] All done! [% END %]
                          The output from the TRY block is left intact up to the point
                          where an exception occurs. For example, this template:
                        
[% TRY %] This gets printed [% THROW food 'carrots' %] This doesn't [% CATCH food %] culinary delights: [% error.info %] [% END %]
generates the following output:
This gets printed culinary delights: carrots
                          The CLEAR directive can be used in a CATCH or
                          FINAL block to clear any output created in the
                          TRY block.
                        
[% TRY %] This gets printed [% THROW food 'carrots' %] This doesn't [% CATCH food %] [% CLEAR %] culinary delights: [% error.info %] [% END %]
Output:
culinary delights: carrots
                          Exception types are hierarchical, with each level being separated by the
                          familiar dot operator. A DBI.connect exception is a more
                          specific kind of DBI error. Similarly, an
                          example.error.barf is a more specific kind of
                          example.error type which itself is also a
                          example error.
                        
                          A CATCH handler that specifies a general exception type
                          (such as DBI or example.error) will also catch
                          more specific types that have the same prefix as long as a more specific
                          handler isn't defined. Note that the order in which CATCH
                          handlers are defined is irrelevant; a more specific handler will always
                          catch an exception in preference to a more generic or default one.
                        
[% TRY %]
   ...
[% CATCH DBI ;
     INCLUDE database/error.html ;
   CATCH DBI.connect ;
     INCLUDE database/connect.html ;
   CATCH ; 
     INCLUDE error.html ;
   END
%]
                        
                          In this example, a DBI.connect error has it's own handler, a
                          more general DBI block is used for all other
                          DBI or DBI.* errors and a default handler
                          catches everything else.
                        
                          Exceptions can be raised in a template using the THROW
                          directive. The first parameter is the exception type which doesn't need
                          to be quoted (but can be, it's the same as INCLUDE) followed
                          by the relevant error message which can be any regular value such as a
                          quoted string, variable, etc.
                        
[% THROW food "Missing ingredients: $recipe.error" %] [% THROW user.login 'no user id: please login' %] [% THROW $myerror.type "My Error: $myerror.info" %]
                          It's also possible to specify additional positional or named parameters
                          to the THROW directive if you want to pass more than just a
                          simple message back as the error info field.
                        
[% THROW food 'eggs' 'flour' msg='Missing Ingredients' %]
                          In this case, the error info field will be a hash array
                          containing the named arguments and an args item which
                          contains a list of the positional arguments.
                        
type => 'food',
info => {
    msg  => 'Missing Ingredients',
    args => ['eggs', 'flour'],
}
                        
                          In addition to specifying individual positional arguments as [%
                          error.info.args.n %], the info hash contains keys
                          directly pointing to the positional arguments, as a convenient shortcut.
                        
[% error.info.0 %] # same as [% error.info.args.0 %]
                          Exceptions can also be thrown from Perl code which you've bound to
                          template variables, or defined as a plugin or other extension. To raise
                          an exception, call die() passing a reference to a Template::Exception
                          object as the argument. This will then be caught by any enclosing
                          TRY blocks from where the code was called.
                        
use Template::Exception;
...
my $vars = {
    foo => sub {
        # ... do something ...
        die Template::Exception->new('myerr.naughty',
                                     'Bad, bad error');
    },
};
                        Template:
[% TRY %]
   [% foo %]
[% CATCH myerr ;
     "Error: $error" ;
   END
%]
                        Output:
Error: myerr.naughty error - Bad, bad error
                          The info field can also be a reference to another object or
                          data structure, if required.
                        
die Template::Exception->new('myerror', { 
    module => 'foo.pl', 
    errors => [ 'bad permissions', 'naughty boy' ],
});
                        Later, in a template:
[% TRY %]
   ...
[% CATCH myerror %]
   [% error.info.errors.size or 'no';
      error.info.errors.size == 1 ? ' error' : ' errors' %]
   in [% error.info.module %]: 
      [% error.info.errors.join(', ') %].
[% END %]
                        Generating the output:
2 errors in foo.pl: bad permissions, naughty boy.
                          You can also call die() with a single string, as is common
                          in much existing Perl code. This will automatically be converted to an
                          exception of the 'undef' type (that's the literal string
                          'undef', not the undefined value). If the string isn't
                          terminated with a newline then Perl will append the familiar " at
                          $file line $line" message.
                        
sub foo {
    # ... do something ...
    die "I'm sorry, Dave, I can't do that\n";
}
                        
                          If you're writing a plugin, or some extension code that has the current
                          Template::Context in
                          scope (you can safely skip this section if this means nothing to you)
                          then you can also raise an exception by calling the context Template::Context#throw() method. You can pass
                          it an Template::Exception object reference, a pair of ($type,
                          $info) parameters or just an $info string to create
                          an exception of 'undef' type.
                        
$context->throw($e);            # exception object
$context->throw('Denied');      # 'undef' type
$context->throw('user.passwd', 'Bad Password');
                  NEXT
Top
                          The NEXT directive can be used to start the next iteration
                          of a FOREACH or WHILE loop.
                        
[% FOREACH user IN users %] [% NEXT IF user.isguest %] Name: [% user.name %] Email: [% user.email %] [% END %]
LAST
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                          The LAST directive can be used to prematurely exit a
                          FOREACH or WHILE loop.
                        
[% FOREACH user IN users %] Name: [% user.name %] Email: [% user.email %] [% LAST IF some.condition %] [% END %]
                          BREAK can also be used as an alias for LAST.
                        
RETURN
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                          The RETURN directive can be used to stop processing the
                          current template and return to the template from which it was called,
                          resuming processing at the point immediately after the
                          INCLUDE, PROCESS or WRAPPER
                          directive. If there is no enclosing template then the Template Template#process() method will return to the
                          calling code with a true value.
                        
Before [% INCLUDE half_wit %] After [% BLOCK half_wit %] This is just half... [% RETURN %] ...a complete block [% END %]
Output:
Before This is just half... After
STOP
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                          The STOP directive can be used to indicate that the
                          processor should stop gracefully without processing any more of the
                          template document. This is a planned stop and the Template Template#process() method will return a
                          true value to the caller. This indicates that the template was
                          processed successfully according to the directives within it.
                        
[% IF something.terrible.happened %]
   [% INCLUDE fatal/error.html %]
   [% STOP %]
[% END %]
[% TRY %]
   [% USE DBI(mydsn) %]
   ...
[% CATCH DBI.connect %]
   <h1>Cannot connect to the database: [% error.info %]</h1>
   <p>
     We apologise for the inconvenience.
   </p>
   [% INCLUDE footer %]
   [% STOP %]
[% END %]
                  CLEAR
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                          The CLEAR directive can be used to clear the output buffer
                          for the current enclosing block. It is most commonly used to clear the
                          output generated from a TRY block up to the point where the
                          error occurred.
                        
[% TRY %] blah blah blah # this is normally left intact [% THROW some 'error' %] # up to the point of error ... [% CATCH %] [% CLEAR %] # clear the TRY output [% error %] # print error string [% END %]
Miscellaneous
TopMETA
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                          The META directive allows simple metadata items to be
                          defined within a template. These are evaluated when the template is
                          parsed and as such may only contain simple values (e.g. it's not possible
                          to interpolate other variables values into META variables).
                        
[% META title = 'The Cat in the Hat' author = 'Dr. Seuss' version = 1.23 %]
                          The template variable contains a reference to the main
                          template being processed. These metadata items may be retrieved as
                          attributes of the template.
                        
<h1>[% template.title %]</h1> <h2>[% template.author %]</h2>
                          The name and modtime metadata items are
                          automatically defined for each template to contain its name and
                          modification time in seconds since the epoch.
                        
[% USE date %] # use Date plugin to format time ... [% template.name %] last modified at [% date.format(template.modtime) %]
                          The PRE_PROCESS and POST_PROCESS options allow
                          common headers and footers to be added to all templates. The
                          template reference is correctly defined when these templates
                          are processed, allowing headers and footers to reference metadata items
                          from the main template.
                        
$template = Template->new({
    PRE_PROCESS  => 'header',
    POST_PROCESS => 'footer',
});
$template->process('cat_in_hat');
                        header:
<html>
  <head>
    <title>[% template.title %]</title>
  </head>
  <body>
                        cat_in_hat:
[% META
     title   = 'The Cat in the Hat'
     author  = 'Dr. Seuss'
     version = 1.23 
     year    = 2000
%]
    The cat in the hat sat on the mat.
                        footer:
    <hr>
    © [% template.year %] [% template.author %]
  </body>
</html>
                        The output generated from the above example is:
<html>
  <head>
    <title>The Cat in the Hat</title>
  </head>
  <body>
    The cat in the hat sat on the mat.
    <hr>
    © 2000 Dr. Seuss
  </body>
</html>
                  TAGS
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                          The TAGS directive can be used to set the
                          START_TAG and END_TAG values on a per-template
                          file basis.
                        
[% TAGS <+ +> %] <+ INCLUDE header +>
                          The TAGS directive may also be used to set a named TAG_STYLE
                        
[% TAGS html %] <!-- INCLUDE header -->
See the Template::Manual::Config#TAGS and Template::Manual::Config#TAG_STYLE configuration options for further details.
DEBUG
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                          The DEBUG directive can be used to enable or disable
                          directive debug messages within a template. The DEBUG
                          configuration option must be set to include DEBUG_DIRS for
                          the DEBUG directives to have any effect. If
                          DEBUG_DIRS is not set then the parser will automatically
                          ignore and remove any DEBUG directives.
                        
                          The DEBUG directive can be used with an on or
                          off parameter to enable or disable directive debugging
                          messages from that point forward. When enabled, the output of each
                          directive in the generated output will be prefixed by a comment indicate
                          the file, line and original directive text.
                        
[% DEBUG on %] directive debugging is on (assuming DEBUG option is set true) [% DEBUG off %] directive debugging is off
                          The format parameter can be used to change the format of the
                          debugging message.
                        
[% DEBUG format '<!-- $file line $line : [% $text %] -->' %]