NAME

    Plate - Fast templating engine with support for embedded Perl

SYNOPSIS

        use Plate;
        
        my $plate = Plate->new(
            path        => '/path/to/plate/files/',
            cache_path  => '/tmp/cache/',
            auto_filter => 'trim',
        );
        
        $plate->filter(html => \&HTML::Escape::escape_html);
        $plate->filter(trim => sub { $_[0] =~ s/^\s+|\s+$//gr });
        
        # Render /path/to/plate/files/hello.plate cached as /tmp/cache/hello.pl
        my $output = $plate->serve('hello');
        print $output;

DESCRIPTION

    Plate is a very fast, efficient and full-featured templating engine.

    Inspired by HTML::Mason and Tenjin, the goal of this templating engine
    is speed and functionality. It has no non-core dependencies, is a
    compact size and supports embedded Perl.

    Features include preprocessing templates, caching compiled templates,
    variable escaping/filtering, localised global variables. Templates can
    also include other templates, with optional content and even define or
    override templates locally.

    All templates have strict, warnings, utf8 and Perl 5.20 features
    enabled.

 Example

    Here is an example template for a letter stored in the file:
    letter.plate

        % my($title, $surname) = @_;
        Dear <% $title %> <% $surname %>,
        
        <& _ &>
        
            Kind Regards,
        
            E. X. Ample

    Another template could include this template, Eg: job.plate

        <&| letter, 'Dr.', 'No' &>\
        In response to the recently advertised position, please
        consider my résumé in your search for a professional sidekick.
        </&>

    Serving the job.plate template will result in the following output:

        Dear Dr. No,
        
        In response to the recent advertised position, please
        consider my résumé in your search for a professional sidekick.
        
                Kind Regards,
        
                E. X. Ample

    Here is the code to render this output:

        use Plate;
        
        my $plate = new Plate;
        my $output = $plate->serve('job');

 Markup

  Variables

        <% $var %>
        <% $unescaped |%>
        <% $filtered |trim |html %>

    Variables are interpolated into the output and optionally filtered
    (escaped). Filters are listed in the order to be applied preceded by a
    | character. If no filter is given as in the first example, then the
    default filter is applied. To explicitly avoid the default filter use
    the empty string as a filter.

  Statements

        % my $user = db_lookup(user => 'bob');
        % for my $var (@list) {

    Lines that start with a % character are treated as Perl statements.

  Comments

        %# Comment line
        <% # inline comment %>
        <%#
            Multi-line
            comment
        %>

  Perl blocks

        <%perl>
        ...
        </%perl>

    Perl code can also be wrapped in a perl block.

  Newlines

    Newline characters can be escaped with a backslash, Eg:

        % for my $var ('a' .. 'c') {
        <% $var %>\
        % }

    This will result in the output abc, all on one line.

  Content

        <& _ &>

    A template can be served with content. This markup will insert the
    content provided, if any.

  Include other templates

        <& header, 'My Title' &>
        ...
        <& footer &>

    A template can include other templates with optional arguments.

  Include other templates with provided content

        <&| paragraph &>
        This content is passed to the "paragraph" template.
        </&>
        
        Plain text, <&| bold &>bold text</&>, plain text.

    An included template can have its own content passed in.

  Def blocks

        <%def copyright>
        Copyright © <% $_[0] %>
        </%def>
        
        <& copyright, 2018 &>

    Local templates can be defined in a template. They can even override
    existing templates.

SUBROUTINES/METHODS

 new

        my $plate = Plate->new(%options);

    Creates a new Plate engine with the options provided.

    Options (with their defaults) are:

    auto_filter => 'html'

      The name of the default filter to use for template variables when no
      filter is specified, <% ... %>. The built-in default filter is a very
      basic HTML filter. Set this to undef to disable the default filter.

      To prevent the default filter being used for just a single variable,
      just set the filter to an empty string. Eg: <% $unfiltered |%>

    cache_code => 1

      If set to a true value, the engine will cache compiled template code
      in memory. This vastly improves performance at the expense of some
      memory.

    cache_path => undef

      Set this to a directory to store compiled templates on the
      filesystem. If the directory does not exist, it will attempt to
      create it using the umask setting.

    cache_suffix => '.pl'

      Compiled templates stored on the filesystem will have this suffix
      appended.

    chomp => 1

      If set to a true value (the default), the final newline in every
      template will be removed.

    encoding => 'UTF-8'

      Set this to the encoding of your template files.

    filters => { html => \&_basic_html_filter }

      A hash of filters to set for use in templates. The key is the name of
      the filter, and the value is the CODE ref, subroutine name or undef.
      The subroutine will be given one argument (the content to filter) as
      a string, and must return the filtered string. To remove a filter
      pass undef as it's value.

      To remove all filters pass undef instead of a HASH ref.

    keep_undef => undef

      If set to a false value (the default), then variables and calls that
      return undef are converted to an empty string.

    max_call_depth => 99

      This sets the maximum call depth to prevent infinite recursion.

    package => 'Plate::Template'

      The package name that templates are compiled and run in.

    path => ''

      The path to the templates on the filesystem. An empty string (the
      default) refers to the current directory. If set to undef then the
      filesystem will not be searched, only cached templates will be
      served.

    static => undef

      If set to a false value (the default), the engine will reload and
      recompile templates whenever files are modified.

      If set to a true value, file modification will not be checked nor
      will templates be reloaded. While this improves performance in
      production, it is not recommended in development.

    suffix => '.plate'

      The suffix appended to template names when searching on the
      filesystem.

    umask => 077

      The umask used when creating cache files and directories.

    vars => {}

      A hash of vars to set for use in templates. This will define new
      local variables to be imported into the templating package when
      compiling and running templates. If the value is not a reference it
      will be a constant in the templating package. To remove a var pass
      undef as it's value.

      To remove all vars pass undef instead of a HASH ref.

      All templates will have access to these variables, subroutines and
      constants even under use strict.

 serve

        my $output = $plate->serve($template_name, @arguments);

    Renders a template. The @arguments will be passed to the template as
    @_.

 serve_with

        my $output = $plate->serve_with($content, $template_name, @arguments);

    Renders a template with the provided content.

    The content can be passed in one of three ways. If $content is a string
    then it is the name of a template to serve. If $content is a SCALAR ref
    then it is the contents of a template to be compiled and served.
    $content may also be a CODE ref which should return the content
    directly.

 content

        % my $content = &Plate::content;

    Used from within a template to return the content passed to that
    template.

 has_content

        % if (Plate::has_content) { ...

    Used from within a template to determine if that template was called
    with content.

 define

        $plate->define($template_name => $content);

    This will cache a template in memory. The $content is the contents of a
    template (as a string) to be compiled or a CODE ref.

    This is useful if you need to use templates that are not stored on the
    file system, for example from a database or a custom subroutine.

 undefine

        $plate->undefine;
        $plate->undefine($template_name);

    This will delete a previously cached template, or all templates if the
    name is undef.

 does_exist

        my $exists = $plate->does_exist($template_name);

    Returns true if a template by that name is cached or exists on the
    filesystem. No attempt will be made to compile the template.

 can_serve

        my $ok = $plate->can_serve($template_name);

    Returns true if a template by that name can be served, otherwise it
    sets $@ to the reason for failure.

 set

        $plate->set(%options);

    Set the options for this Plate engine. Options are the same as those
    for "new".

AUTHOR

    Vernon Lyon <vlyon@cpan.org>

BUGS

    Please report any bugs or feature requests on GitHub issues
    <https://github.com/vlyon/Plate/issues>.

SOURCE

    The source code is hosted on GitHub <https://github.com/vlyon/Plate>.
    Feel free to fork the repository and submit pull requests!

SUPPORT

    You can find documentation for this module with the perldoc command.

        perldoc Plate

    You can also read the documentation online on metacpan
    <https://metacpan.org/pod/Plate>.

COPYRIGHT AND LICENSE

    Copyright (C) 2018, Vernon Lyon.

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

