phpman > perldoc > Template::Provider(3pm)

NAME
    Template::Provider - Provider module for loading/compiling templates

SYNOPSIS
        $provider = Template::Provider->new(\%options);

        ($template, $error) = $provider->fetch($name);

DESCRIPTION
    The Template::Provider is used to load, parse, compile and cache template documents. This object
    may be sub-classed to provide more specific facilities for loading, or otherwise providing
    access to templates.

    The Template::Context objects maintain a list of Template::Provider objects which are polled in
    turn (via fetch()) to return a requested template. Each may return a compiled template, raise an
    error, or decline to serve the request, giving subsequent providers a chance to do so.

    The Template::Provider can also be subclassed to provide templates from a different source, e.g.
    a database. See SUBCLASSING below.

    This documentation needs work.

PUBLIC METHODS
  new(\%options)
    Constructor method which instantiates and returns a new "Template::Provider" object. A reference
    to a hash array of configuration options may be passed.

    See "CONFIGURATION OPTIONS" below for a summary of configuration options and
    Template::Manual::Config for full details.

  fetch($name)
    Returns a compiled template for the name specified. If the template cannot be found then
    "(undef, STATUS_DECLINED)" is returned. If an error occurs (e.g. read error, parse error) then
    "($error, STATUS_ERROR)" is returned, where $error is the error message generated. If the
    TOLERANT option is set the the method returns "(undef, STATUS_DECLINED)" instead of returning an
    error.

  load($name)
    Loads a template without parsing or compiling it. This is used by the the INSERT directive.

  store($name, $template)
    Stores the compiled template, $template, in the cache under the name, $name. Susbequent calls to
    "fetch($name)" will return this template in preference to any disk-based file.

  include_path(\@newpath)
    Accessor method for the "INCLUDE_PATH" setting. If called with an argument, this method will
    replace the existing "INCLUDE_PATH" with the new value.

  paths()
    This method generates a copy of the "INCLUDE_PATH" list. Any elements in the list which are
    dynamic generators (e.g. references to subroutines or objects implementing a "paths()" method)
    will be called and the list of directories returned merged into the output list.

    It is possible to provide a generator which returns itself, thus sending this method into an
    infinite loop. To detect and prevent this from happening, the $MAX_DIRS package variable, set to
    64 by default, limits the maximum number of paths that can be added to, or generated for the
    output list. If this number is exceeded then the method will immediately return an error
    reporting as much.

CONFIGURATION OPTIONS
    The following list summarises the configuration options that can be provided to the
    "Template::Provider" new() constructor. Please consult Template::Manual::Config for further
    details and examples of each configuration option in use.

  INCLUDE_PATH
    The INCLUDE_PATH option is used to specify one or more directories in which template files are
    located.

        # single path
        my $provider = Template::Provider->new({
            INCLUDE_PATH => '/usr/local/templates',
        });

        # multiple paths
        my $provider = Template::Provider->new({
            INCLUDE_PATH => [ '/usr/local/templates',
                              '/tmp/my/templates' ],
        });

  ABSOLUTE
    The ABSOLUTE flag is used to indicate if templates specified with absolute filenames (e.g.
    '"/foo/bar"') should be processed. It is disabled by default and any attempt to load a template
    by such a name will cause a '"file"' exception to be raised.

        my $provider = Template::Provider->new({
            ABSOLUTE => 1,
        });

  RELATIVE
    The RELATIVE flag is used to indicate if templates specified with filenames relative to the
    current directory (e.g. "./foo/bar" or "../../some/where/else") should be loaded. It is also
    disabled by default, and will raise a "file" error if such template names are encountered.

        my $provider = Template::Provider->new({
            RELATIVE => 1,
        });

  DEFAULT
    The DEFAULT option can be used to specify a default template which should be used whenever a
    specified template can't be found in the INCLUDE_PATH.

        my $provider = Template::Provider->new({
            DEFAULT => 'notfound.html',
        });

    If a non-existant template is requested through the Template process() method, or by an
    "INCLUDE", "PROCESS" or "WRAPPER" directive, then the "DEFAULT" template will instead be
    processed, if defined. Note that the "DEFAULT" template is not used when templates are specified
    with absolute or relative filenames, or as a reference to a input file handle or text string.

  ENCODING
    The Template Toolkit will automatically decode Unicode templates that have a Byte Order Marker
    (BOM) at the start of the file. This option can be used to set the default encoding for
    templates that don't define a BOM.

        my $provider = Template::Provider->new({
            ENCODING => 'utf8',
        });

    See Encode for further information.

  CACHE_SIZE
    The CACHE_SIZE option can be used to limit the number of compiled templates that the module
    should cache. By default, the CACHE_SIZE is undefined and all compiled templates are cached.

        my $provider = Template::Provider->new({
            CACHE_SIZE => 64,   # only cache 64 compiled templates
        });

  STAT_TTL
    The STAT_TTL value can be set to control how long the "Template::Provider" will keep a template
    cached in memory before checking to see if the source template has changed.

        my $provider = Template::Provider->new({
            STAT_TTL => 60,  # one minute
        });

  COMPILE_EXT
    The COMPILE_EXT option can be provided to specify a filename extension for compiled template
    files. It is undefined by default and no attempt will be made to read or write any compiled
    template files.

        my $provider = Template::Provider->new({
            COMPILE_EXT => '.ttc',
        });

  COMPILE_DIR
    The COMPILE_DIR option is used to specify an alternate directory root under which compiled
    template files should be saved.

        my $provider = Template::Provider->new({
            COMPILE_DIR => '/tmp/ttc',
        });

  TOLERANT
    The TOLERANT flag can be set to indicate that the "Template::Provider" module should ignore any
    errors encountered while loading a template and instead return "STATUS_DECLINED".

  PARSER
    The PARSER option can be used to define a parser module other than the default of
    Template::Parser.

        my $provider = Template::Provider->new({
            PARSER => MyOrg::Template::Parser->new({ ... }),
        });

  DEBUG
    The DEBUG option can be used to enable debugging messages from the Template::Provider module by
    setting it to include the "DEBUG_PROVIDER" value.

        use Template::Constants qw( :debug );

        my $template = Template->new({
            DEBUG => DEBUG_PROVIDER,
        });

SUBCLASSING
    The "Template::Provider" module can be subclassed to provide templates from a different source
    (e.g. a database). In most cases you'll just need to provide custom implementations of the
    "_template_modified()" and "_template_content()" methods. If your provider requires and custom
    initialisation then you'll also need to implement a new "_init()" method.

    Caching in memory and on disk will still be applied (if enabled) when overriding these methods.

  _template_modified($path)
    Returns a timestamp of the $path passed in by calling "stat()". This can be overridden, for
    example, to return a last modified value from a database. The value returned should be a
    timestamp value (as returned by "time()", although a sequence number should work as well.

  _template_content($path)
    This method returns the content of the template for all "INCLUDE", "PROCESS", and "INSERT"
    directives.

    When called in scalar context, the method returns the content of the template located at $path,
    or "undef" if $path is not found.

    When called in list context it returns "($content, $error, $mtime)", where $content is the
    template content, $error is an error string (e.g. ""$path: File not found""), and $mtime is the
    template modification time.

AUTHOR
    Andy Wardley <abw AT wardley.org> <http://wardley.org/>

COPYRIGHT
    Copyright (C) 1996-2007 Andy Wardley. All Rights Reserved.

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

SEE ALSO
    Template, Template::Parser, Template::Context