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shopify-liquid

shopify-liquid

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A Liquid template engine with a wide range of tags and filters, for both Node.js and browsers. Here's a live demo: http://harttle.com/shopify-liquid/

The Liquid template engine is implemented in Ruby originally, which is used by Jekyll and Github Pages.

Features:

API Reference:

Installation:

npm install --save shopify-liquid

Render from String

Parse and Render:

var Liquid = require('shopify-liquid');
var engine = Liquid();
 
engine.parseAndRender('{{name | capitalize}}', {name: 'alice'})
    .then(function(html){
        // html === 'Alice' 
    });

Caching templates:

var tpl = engine.parse('{{name | capitalize}}');
engine.render(tpl, {name: 'alice'})
    .then(function(html){   
        // html === 'Alice' 
    });

Render from File

var engine = Liquid({
    root: path.resolve(__dirname, 'views/'),  // dirs to lookup layouts/includes 
    extname: '.liquid'          // the default extname used for layouts/includes 
});
engine.renderFile("hello.liquid", {name: 'alice'})
    .then(function(html){
       // html === 'Alice' 
    });
// equivalent to:  
engine.renderFile("hello", {name: 'alice'})
    .then(function(html){
       // html === 'Alice' 
    });

Options

The full list of options for Liquid() is listed as following:

  • root is a directory or an array of directories to resolve layouts and includes, as well as the filename passed in when calling .renderFile(). If an array, the files are looked up in the order they occur in the array. Defaults to ["."]

  • extname is used to lookup the template file when filepath doesn't include an extension name. Defaults to ".liquid"

  • cache indicates whether or not to cache resolved templates. Defaults to false.

  • strict_filters is used to enable strict filter existence. If set to false, undefined filters will be rendered as empty string. Otherwise, undefined filters will cause an exception. Defaults to false.

  • strict_variables is used to enable strict variable derivation. If set to false, undefined variables will be rendered as empty string. Otherwise, undefined variables will cause an exception. Defaults to false.

  • trim_right is used to strip blank characters (including , \t, and \r) from the right of tags ({% %}) until \n (inclusive). Defaults to false.

  • trim_left is similiar to trim_right, whereas the \n is exclusive. Defaults to false. See Whitespace Control for details.

  • greedy is used to specify whether trim_left/trim_right is greedy. When set to true, all successive blank characters including \n will be trimed regardless of line breaks. Defaults to false.

Use with Express.js

// register liquid engine 
app.engine('liquid', engine.express()); 
app.set('views', './views');            // specify the views directory 
app.set('view engine', 'liquid');       // set to default 

There's an Express demo here.

When using with Express.js, partials(includes and layouts) will be looked up in both Liquid root and Express views directories.

Use in Browser

Download the dist files and import into your HTML. And window.Liquid is what you want. There's also a demo.

<html lang="en">
<head>
  <script src="dist/liquid.min.js"></script> 
</head>
<body>
  <script>
    var engine = window.Liquid();
    var src = '{{ name | capitalize}}';
    var ctx = {
      name: 'welcome to Shopify Liquid'
    };
    engine.parseAndRender(src, ctx)
      .then(function(html) {
        // html === Welcome to Shopify Liquid  
      });
  </script> 
</body>
</html>

Note: In IE and Android UC browser, you need a Promise implementation registered to any-promise.

Includes

// file: color.liquid
color: '{{ color }}' shape: '{{ shape }}'

// file: theme.liquid
{% assign shape = 'circle' %}
{% include 'color' %}
{% include 'color' with 'red' %}
{% include 'color', color: 'yellow', shape: 'square' %}

The output will be:

color: '' shape: 'circle'
color: 'red' shape: 'circle'
color: 'yellow' shape: 'square'

Layouts

// file: default-layout.liquid
Header
{% block content %}My default content{% endblock %}
Footer

// file: page.liquid
{% layout "default-layout" %}
{% block content %}My page content{% endblock %}

The output of page.liquid:

Header
My page content
Footer
  • It's possible to define multiple blocks.
  • block name is optional when there's only one block.

Register Filters

// Usage: {{ name | uppper }} 
engine.registerFilter('upper', function(v){
    return v.toUpperCase();
});

See existing filter implementations: https://github.com/harttle/shopify-liquid/blob/master/filters.js

Register Tags

// Usage: {% upper name%} 
engine.registerTag('upper', {
    parse: function(tagToken, remainTokens) {
        this.str = tagToken.args; // name 
    },
    render: function(scope, hash) {
        var str = Liquid.evalValue(this.str, scope); // 'alice' 
        return Promise.resolve(str.toUpperCase()); // 'Alice' 
    }
});

See existing tag implementations: https://github.com/harttle/shopify-liquid/blob/master/tags/

Contribution Guide

  1. Write a test to define the feature you want.
  2. File an issue, or optionally:
  3. Get your test pass and make a pull request.