NAME
Template::Liquid - A Simple, Stateless Template System
Synopsis
use Template::Liquid;
my $template = Template::Liquid->new();
$template->parse( # See Template::Liquid::Tag for more examples
'{% for x in (1..3) reversed %}{{ x }}, {% endfor %}{{ some.text }}'
);
print $template->render({some => {text => 'Contact!'}}); # 3, 2, 1, Contact!Description
Template::Liquid is a template engine based on Liquid. The Liquid template engine was crafted for very specific requirements:
It has to have simple markup and beautiful results. Template engines which don't produce good looking results are no fun to use.
It needs to be non-evaling and secure. Liquid templates are made so that users can edit them. You don't want to run code on your server which your users wrote.
It has to be stateless. The compile and render steps have to be separate, so that the expensive parsing and compiling can be done once; later on, you can just render it by passing in a hash with local variables and objects.
It needs to be able to style emails as well as HTML.
Getting Started
It's very simple to get started with Solution. Just as in Liquid, templates are built and used in two steps: Parse and Render.
my $sol = Template::Liquid->new(); # Create a Template::Liquid object
$sol->parse('Hi, {{name}}!'); # Parse and compile the template
$sol->render({name => 'Sanko'}); # Render the output => "Hi, Sanko!"
# Or if you're in a hurry...
Template::Liquid->parse('Hi, {{name}}!')->render({name => 'Sanko'});The parse step creates a fully compiled template which can be re-used as often as you like. You can store it in memory or in a cache for faster rendering later.
All parameters you want Template::Liquid to work with have to be passed as parameters to the render method. Template::Liquid is a closed ecosystem; it does not know about your local, instance, global, or environment variables.
For an expanded overview of the Liquid/Solution syntax, please see Template::Liquid::Tag and read Liquid for Designers.
Extending Template::Liquid
Extending the Template::Liquid template engine for your needs is almost too simple. Keep reading.
Custom Filters
Filters are simple subs called when needed. They are not passed any state data by design and must return the modified content.
Template::Liquid->register_filter( ... )
This registers a package which Template::Liquid will assume contains one or more filters.
# Register a package as a filter
Template::Liquid->register_filter( 'Template::Solution::Filter::Amalgamut' );
# Or simply say...
Template::Liquid->register_filter( );
# ...and Template::Liquid will assume the filters are in the calling packageCustom Tags
See the section entitled Extending Template::Liquid with Custom Tags in Template::Liquid::Tag for more information.
To assist with custom tag creation, Template::Liquid provides several basic tag types for subclassing and exposes the following methods:
Template::Liquid->register_tag( ... )
This registers a package which must contain (directly or through inheritance) both a parse and render method.
# Register a new tag which Template::Liquid will look for in the given package
Template::Liquid->register_tag( 'newtag', 'Template::Solution::Tag::You're::It' );
# Or simply say...
Template::Liquid->register_tag( 'newtag' );
# ...and Template::Liquid will assume the new tag is in the calling packagePre-existing tags are replaced when new tags are registered with the same name. You may want to do this to override some functionality.
For an example of a custom tag, see Template::Solution::Tag::Include.
Why should I use Template::Liquid?
You want to allow your users to edit the appearance of your application, but don't want them to run insecure code on your server.
You want to render templates directly from the database.
You like Smarty-style template engines.
You need a template engine which does HTML just as well as email.
You don't like the markup language of your current template engine.
You wasted three days reinventing this wheel when you could have been doing something productive like volunteering or catching up on past seasons of Doctor Who.
Why shouldn't I use Template::Liquid?
You've found or written a template engine which fills your needs better than Liquid or Template::Liquid ever could.
You are uncomfortable with text that you didn't copy and paste yourself. Everyone knows computers cannot be trusted.
Template::LiquidX or Template::Solution?
I'd really rather use Template::Solution::{Package} for extentions but who cares? Namespaces are kinda useless if you're the only person using the code.
As I understand it, the original project's name, Liquid, is a reference to the classical states of matter (the engine itself being stateless). I settled on solution because it's liquid but... with... bits of other stuff floating in it. (Pretend you majored in chemistry instead of mathematics or computer science.) Liquid tempates will always be work with Template::Liquid but (due to Template::Solutions's expanded syntax) Template::Solution templates may not be compatible with Liquid or Template::Liquid.
This 'solution' is not the answer to all your problems and obviously not the only solution for your templating troubles. It's simply a solution.
Author
Sanko Robinson <sanko@cpan.org> - http://sankorobinson.com/
CPAN ID: SANKO
The original Liquid template system was developed by jadedPixel and Tobias Lütke.
License and Legal
Copyright (C) 2009,2010 by Sanko Robinson <sanko@cpan.org>
This program is free software; you can redistribute it and/or modify it under the terms of The Artistic License 2.0. See the LICENSE file included with this distribution or notes on the Artistic License 2.0 for clarification.
When separated from the distribution, all original POD documentation is covered by the Creative Commons Attribution-Share Alike 3.0 License. See the clarification of the CCA-SA3.0.