Text::Xslate::Syntax::TTerse(3pm) User Contributed Perl Documentation Text::Xslate::Syntax::TTerse(3pm)

Text::Xslate::Syntax::TTerse - An alternative syntax compatible with Template Toolkit 2

    use Text::Xslate;
    my $tx = Text::Xslate->new(
        syntax => 'TTerse',
    );
    print $tx->render_string(
        'Hello, [% dialect %] world!',
        { dialect => 'TTerse' }
    );
    # PRE_PROCESS/POST_PROCESS
    $tx = Text::Xslate->new(
        syntax => 'TTerse',
        header => ['header.tt'],
        footer => ['footer.tt'],
    );

TTerse is a subset of the Template-Toolkit 2 (and partially 3) syntax, using "[% ... %]" tags and "%% ..." line code.

Note that TTerse itself has few methods and filters while Template-Toolkit 2 has a lot. See "Text::Xslate::Bridge::*" modules on CPAN which provide extra methods and filters if you want to use those features.

(TODO: I should concentrate on the difference between Template-Toolkit 2 and TTerse)

This supports a Template-Toolkit compatible syntax, although the details might be different.

Note that lower-cased keywords, which are inspired in Template-Toolkit 3, are also allowed.

Scalar access:

    [%  var %]
    [% $var %]
    [% GET var # 'GET' is optional %]

Field access:

    [% var.0 %]
    [% var.field %]
    [% var.accessor %]
    [% var.$field ]%
    [% var[$field] # TTerse specific %]

Variables may be HASH references, ARRAY references, or objects.

If $var is an object instance, you can call its methods.

    [% $var.method() %]
    [% $var.method(1, 2, 3) %]
    [% $var.method(foo => [1, 2, 3]) %]
    [% $var.method({ foo => 'bar' }) %]

Almost the same as Text::Xslate::Syntax::Kolon, but "infix:<_>" for concatenation is supported for compatibility.

    [% FOREACH item IN arrayref %]
        * [% item %]
    [% END %]

Loop iterators are partially supported.

    [% FOREACH item IN arrayref %]
        [%- IF loop.is_first -%]
        <first>
        [%- END -%]
        * [% loop.index %]  # 0 origin
        * [% loop.count     # loop.index + 1 %]
        * [% loop.body      # alias to arrayref %]
        * [% loop.size      # loop.body.size %]
        * [% loop.max_index # loop.size - 1 %]
        * [% loop.peek_next # loop.body[ loop.index + 1 %]
        * [% loop.peek_prev # loop.body[ loop.index - 1 %]
        [%- IF loop.is_last -%]
        <last>
        [%- END -%]
    [% END %]

Unlike Template-Toolkit, "FOREACH" doesn't accept a HASH reference, so you must convert HASH references to ARRAY references by keys(), values(), or kv() methods.

Template-Toolkit compatible names are also supported, but the use of them is discouraged because they are not easy to understand:

    loop.max   # for loop.max_index
    loop.next  # for loop.peek_next
    loop.prev  # for loop.peek_prev
    loop.first # for loop.is_first
    loop.last  # for loop.is_last

Loop control statements, namely "NEXT" and "LAST", are also supported in both "FOR" and "WHILE" loops.

    [% FOR item IN data -%]
        [% LAST IF item == 42 -%]
        ...
    [% END -%]

    [% IF logical_expression %]
        Case 1
    [% ELSIF logical_expression %]
        Case 2
    [% ELSE %]
        Case 3
    [% END %]
    [% UNLESS logical_expression %]
        Case 1
    [% ELSE %]
        Case 2
    [% END %]
    [% SWITCH expression %]
    [% CASE case1 %]
        Case 1
    [% CASE case2 %]
        Case 2
    [% CASE DEFAULT %]
        Case 3
    [% END %]

    [% var | f %]
    [% f(var)  %]

The "INCLUDE" statement is supported.

    [% INCLUDE "file.tt" %]
    [% INCLUDE $var %]

"WITH variables" syntax is also supported, although the "WITH" keyword is optional in Template-Toolkit:

    [% INCLUDE "file.tt" WITH foo = 42, bar = 3.14 %]
    [% INCLUDE "file.tt" WITH
        foo = 42
        bar = 3.14
    %]

The "WRAPPER" statement is also supported. The argument of "WRAPPER", however, must be string literals, because templates will be statically linked while compiling.

    [% WRAPPER "file.tt" %]
    Hello, world!
    [% END %]
    %%# with variable
    [% WRAPPER "file.tt" WITH title = "Foo!" %]
    Hello, world!
    [% END %]

The content will be set into "content", but you can specify its name with the "INTO" keyword.

    [% WRAPPER "foo.tt" INTO wrapped_content WITH title = "Foo!" %]
    ...
    [% END %]

This is a syntactic sugar to template cascading. Here is a counterpart of the example in Kolon.

    : macro my_content -> {
        Hello, world!
    : }
    : cascade "file.tx" { content => my_content() }

Note that the WRAPPER option (<http://template-toolkit.org/docs/manual/Config.html#section_WRAPPER>) in Template-Toolkit is not supported directly. Instead, you can emulate it with "header" and "footer" options as follows:

    my %vpath = (
        wrap_begin => '[% WRAPPER "base" %]',
        wrap_end => '[% END %]',
        base => 'Hello, [% content %] world!' . "\n",
        content => 'Xslate',
    );
    my $tx = Text::Xslate->new(
        syntax => 'TTerse',
        path => \%vpath,
        header => ['wrap_begin'],
        footer => ['wrap_end'],
    );
    print $tx->render('content'); # => Hello, Xslate world!;

Definition:

    [% MACRO foo BLOCK -%]
        This is a macro.
    [% END -%]
    [% MACRO add(a, b) BLOCK -%]
    [%  a + b -%]
    [% END -%]

Call:

    [% foo()     %]
    [% add(1, 2) %]

Unlike Template-Toolkit, calling macros requires parens ("()").

A few methods are supported in the Xslate core.

    %% a.size();
    %% a.join(", ");
    %% a.reverse();
    %% h.size();
    %% h.keys();
    %% h.values();
    %% h.kv();

However, there is a bridge mechanism that allows you to use external methods. For example, Text::Xslate::Bridge::TT2 provides the TT2 virtual methods for Xslate, which bridges Template::VMethods implementation.

    use Text::Xslate::Bridge::TT2;
    my $tx = Text::Xslate->new(
        syntax => 'TTerse',
        module => [qw(Text::Xslate::Bridge::TT2)],
    );
   print $tx->render_string('[% "foo".length() %]'); # => 3

See Text::Xslate::Bridge, or search for "Text::Xslate::Bridge::*" on CPAN.

CALL evaluates expressions, but does not print it.

    [% CALL expr %]

SET and assignments, although the use of them are strongly discouraged.

    [% SET var1 = expr1, var2 = expr2 %]
    [% var = expr %]

DEFAULT statements as a syntactic sugar to "SET var = var // expr":

    [% DEFAULT lang = "TTerse" %]

FILTER blocks to apply filters to text sections:

    [% FILTER html -%]
    Hello, <Xslate> world!
    [% END -%]

There are some differences between TTerse and Template-Toolkit.

Text::Xslate

Template (Template::Toolkit)

Template::Tiny

Text::Xslate::Bridge::TT2

Text::Xslate::Bridge::TT2Like

Text::Xslate::Bridge::Alloy

2024-03-31 perl v5.38.2