Liquid Basics

Liquid Template Syntax Basics

This is an introduction to the Spiffy Stores Liquid template syntax, and a reference for Spiffy Stores-specific Tags and Filters.

Liquid is the templating engine for customizing your store layout. It's a small and fast template language which is quick and easy to learn but contains very powerful features for full customization.

The Spiffy Stores Liquid Variables Reference can be found here.

Basics

There are two types of markup in liquid: Output and Tag.

• Output is surrounded by

   {{ two curly brackets }} 

• Tags are surrounded by

   {% a curly bracket and a percent %} 

Output blocks will always be replaced with the data which they reference.

For instance if your liquid template has a product object exposed to it you can print the name of the product to the screen by referencing

 {{ product.title }} 

Tags drive the logic of templates. They are responsible for loops and branching logic such as If / Else.

Output

Here is a simple example of Output:

Hello {{name}}
Hello {{user.name}}
Hello {{ 'fred' }}

Acceptable Tags and Comments

We sanitize all templates, so that you may not use javascript or tags that might be harmful to the application. Disallowed tags include, but aren’t limited to:

• HEAD
• BODY
• SCRIPT

Comments

HTML comments are automatically sanitized by our system. If you wish to place comments in your code, do it with a liquid comment, like so:

 {{ # This is a comment in liquid, and won't show up on the output }} 

Filters

Output markup takes filters. Filters are simple methods. The first parameter is always the output of the left side of the filter. The return value of the filter will be the new left value when the next filter is run. When there are no more filters the template will receive the resulting string.

Hello {{ 'fred' | upcase }}
Hello fred has {{ 'fred' | length }} letters!
Hello {{ '*fred*' | textilize | upcase }}
Hello {{ 'now' | date: "%Y %h" }}

Filter Reference

asset_url(input)	Returns the URL for an asset. {{ 'shop.css' | asset_url }} The above example returns the path plus filename of the specified file. In this case it could be something like: "http://asset2.spiffyserver.com/sites/3457/shop.css" You will most probably use this URL with another filter to create a link or an include tag for instance: {{ 'shop.css' | asset_url | stylesheet_tag }}
capitalize(input)	Capitalize all words in the input string. {{ variant.title | capitalize }}
date(input, format)	Reformat a date using an optional format string. Please see below for a list of the valid format characters. %a - The abbreviated weekday name ("Sun") %A - The full weekday name ("Sunday") %b - The abbreviated month name ("Jan") %B - The full month name ("January") %c - The preferred local date and time representation %d - Day of the month (01..31) %H - Hour of the day, 24-hour clock (00..23) %I - Hour of the day, 12-hour clock (01..12) %j - Day of the year (001..366) %m - Month of the year (01..12) %M - Minute of the hour (00..59) %p - Meridian indicator ("AM" or "PM") %S - Second of the minute (00..60) %U - Week number of the current year, starting with the first Sunday as the first day of the first week (00..53) %W - Week number of the current year, starting with the first Monday as the first day of the first week (00..53) %w - Day of the week (Sunday is 0, 0..6) %x - Preferred representation for the date alone, no time %X - Preferred representation for the time alone, no date %y - Year without a century (00..99) %Y - Year with century %Z - Time zone name %% - Literal "%" character {{ order_date | date: "%m %B, %Y" }}
default_pagination(paginate)	This filter is to be used in conjunction with the Liquid Paginate Tag. It will produce default pagination for the paginated collection if you pipe in the paginate hash which is created by the Liquid Paginate Tag. <div id="paginate"> {{ paginate | default_pagination }}</div>
downcase(input)	Convert a string to lower case. {{ variant.title | downcase }}
escape(input)	URL encode a string so that all special characters are converted to their % form and can be recognised by browsers. This may also be aliased as "h". {{ product.url | escape }}
first(array)	Get the first element of an array. {{ product.images | first | to_img }}
global_asset_url(input)	Returns the URL for a global asset. Global assets are kept in a certain directory on the Spiffy Stores web servers which is aggressively cached and compressed. Using assets from this global directory can improve the loading times of your pages dramatically. Here's a complete listing of all the global assets available: {{ 'prototype.js' | global_asset_url | script_tag }} {{ 'builder.js' | global_asset_url | script_tag }} {{ 'controls.js' | global_asset_url | script_tag }} {{ 'dragdrop.js' | global_asset_url | script_tag }} {{ 'effects.js' | global_asset_url | script_tag }} {{ 'scriptaculous.js' | global_asset_url | script_tag }} {{ 'slider.js' | global_asset_url | script_tag }} {{ 'sound.js' | global_asset_url | script_tag }} {{ 'lightbox.css' | global_asset_url | stylesheet_tag }} {{ 'lightbox.js' | global_asset_url | script_tag }} {{ 'lightbox/v1/lightbox.css' | global_asset_url | stylesheet_tag }} {{ 'lightbox/v1/lightbox.js' | global_asset_url | script_tag }} {{ 'lightbox/v2/lightbox.css' | global_asset_url | stylesheet_tag }} {{ 'lightbox/v2/lightbox.js' | global_asset_url | script_tag }}
highlight_active_tag(tag, css_class='active')
img_tag(url, alt="")	Creates an IMG tag for a file you've uploaded to the server for use inside your document. Ex: {{ 'image_name.jpg' | image_tag }}
join(input, glue = ' ')	Join elements of an array with an optional join character, which defaults to a space. {{ names | join: ',' }}
last(array)	Get the last element of an array. {{ product.images | last | to_img }}
link_to(link, url, title="")	A link_to filter creates a link (<a href="...>) for the given parameters. The first parameter is the link name, the second is the URL and the third parameter specifies the title, but is optional. {{ 'Spiffy Stores' | link_to: 'http://www.spiffystores.com.au', 'The best shopping cart on the planet' }}
link_to_add_tag(label, tag)
link_to_remove_tag(label, tag)
link_to_tag(label, tag, all=false)
link_to_type(type)
link_to_vendor(vendor)
money(money)
money_rounded(money)
money_with_currency(money)
money_without_currency(money)
pluralize(input, singular, plural)
product_img_url(url, style = 'small')
script_tag(url)	This filter takes a URL with a .js file and puts a script tag around it. Use this filter in the page header for all your javascript files. {{ 'shop.js' | asset_url | script_tag }}
stylesheet_tag(url, media="all")	This filter takes a URL with a .css file and puts a link tag around it. Use this filter in the page header for all your stylesheet files. {{ 'shop.css' | asset_url | stylesheet_tag }}
size(input)	Return the size of an array or of a string. {{ variant.title | size }}
sort(array)	Sorts the elements in an array. {{ names | sort | join: ',' ) }}
strip_html(input)	Strip out any html tags. This is a simple filter which removes any characters in the form of an HTML tag, such as "<...>". This can be useful in combination with truncate, to generate fragment summaries of formatted text. {{ 'my long<br>string' | strip_html }}
truncate(input, length = 50, truncate_string = "...")	Truncate a string down to x characters. Additionally, a character string can be specified to indicate that truncation has occurred. {{ 'my long string' | truncate: 50, '...' }}
truncatewords(input, words = 15, truncate_string = "...")	Truncate a string down to a number of words. This is the same as "truncate", except that the length is specified in words, rather than characters. {{ 'my long string' | truncatewords: 2, '...' }}
unescape(input)
upcase(input)	Convert a string to upper case. {{ variant.title | upcase }}
url_encode(input)
url_for_type(type_title)
url_for_vendor(vendor_title)
weight(grams)
weight_with_unit(grams)
within(product_url, collection)

Tags

Tags are for the logic in your template.

Comments

A comment is the simplest of tags. It just swallows content.

Hi fred {% comment %} you stink {% endcomment %}

Variable Assignment

You can store data in your own variables, to be used in output or other tags as desired.

The simplest way to create a variable is with the assign tag, which has a pretty straightforward syntax:

{% assign name = 'freestyle' %}
{% for t in collections.tags %}{% if t == name %}
  <p>Freestyle!</p>
{% endif %}{% endfor %}

Another way of doing this would be to assign true/false values to the variable:

{% assign freestyle = false %}
{% for t in collections.tags %}{% if t == 'freestyle' %}
  {% assign freestyle = true %}
{% endif %}{% endfor %}
{% if freestyle %}
  <p>Freestyle!</p>
{% endif %}

If you want to combine a number of strings into a single string and save it to a variable, you can do that with the capture tag. This tag is a block which "captures" whatever is rendered inside it and assigns it to the given variable instead of rendering it to the screen. Here's how it works:

  {% capture attribute_name %}{{ item.title }}-{{ i }}-color{% endcapture %}

  <label for="{{ attribute_name }}">Colour:</label>
  <select name="attributes[{{ attribute_name }}]" id="{{ attribute_name }}">
    <option value="red">Red</option>
    <option value="green">Green</option>
    <option value="blue">Blue</option>
  </select>

If / Else

The conditional expressions formed with If/Else should be a familiar construction from most programming languages. Liquid allows you to write simple expressions in the if.

{% if user %}
  Hi {{ user.name }}
{% endif %}

{% if user.name == 'fred' %}
  hi fred
{% endif %}

{% if user.name != 'fred' %}
  you aren't fred
{% endif %}

{% if user.creditcard == null %}
   user has no credit
{% endif %}

{% if user.payments == empty %}
   you never paid !
{% endif %}

{% if user.age > 18 %}
   Login here
{% else %}
   Sorry, you are too young
{% endif %}

Case Statement

If you need more than one condition you can use the Case statement

{% case line_item.quantity %}
  {% when 0 %}
  none
  {% when 1 %}
  one
  {% when 2 %}
  two
  {% else %}
  a few more...
{% endcase %}

Example:

{% case template %}
	
{% when 'label' %}
     // {{ label.title }}
{% when 'product' %}
     // {{ product.vendor | link_to_vendor }} / {{ product.title }}
{% else %}
     // {{page_title}
{% endcase %}

Cycle

Often you have to cycle through an number of alternative values. Liquid has built-in support for such operations using the Cycle tag.

{% cycle 'one', 'two', 'three' %}
{% cycle 'one', 'two', 'three' %}
{% cycle 'one', 'two', 'three' %}
{% cycle 'one', 'two', 'three' %}

...will result in...

one
two
three
one

If no name is supplied for the cycle group then its assumed that multiple calls with the same parameters are one group.

If you want to have total control over cycle groups you can optionally specify the name of the group. This can even be a variable.

{% cycle 'group 1': 'one', 'two', 'three' %}
{% cycle 'group 1': 'one', 'two', 'three' %}
{% cycle 'group 2': 'one', 'two', 'three' %}
{% cycle 'group 2': 'one', 'two', 'three' %}

...will result in...

one
two
one
two

For Loops

Liquid allows for loops over collections. This allows you to loop over things like line-items in an order.

  {% for item in order.line-items %}
    {{ item.description }}
  {% endfor %}

During every For loop, the following helper variables are available for additional control over the results.

 forloop.length       # => length of the entire for loop
 forloop.index	      # => index of the current iteration
 forloop.index0	      # => index of the current iteration (zero based)
 forloop.rindex       # => how many items are still left?
 forloop.rindex0      # => how many items are still left? (zero based)
 forloop.first	      # => is this the first iteration?
 forloop.last	      # => is this the last iteration?

There are several attributes you can use to influence which items you receive in your loop

• limit lets you restrict how many items you get
• offset lets you start the collection with the nth item.

  # array = [1,2,3,4,5,6]
  {% for item in array limit:2 offset:2 %}
    {{ item }}
  {% endfor %}
  # results in 3,4

Instead of looping over an existing collection, you can define a range of numbers to loop through. The range can be defined by both literal and variable numbers:

  # if item.quantity is 4...
  {% for i in (1..item.quantity) %}
    {{ i }}
  {% endfor %}
  # results in 1,2,3,4

Tables

Liquid can also create table rows and cells for you, although you still need to wrap a table tag around the tablerow tag.

  <table>
    {% tablerow item in items cols: 3 limit: 12 %}
      {{ item.variable }}
    {% endtablerow %}
  </table>

You can also find out whether a table cell is the first or last column in a row or directly query the column number.

 tablerowloop.length       # => length of the entire for loop
 tablerowloop.index	   # => index of the current iteration
 tablerowloop.index0	      # => index of the current iteration (zero based)
 tablerowloop.rindex       # => how many items are still left?
 tablerowloop.rindex0      # => how many items are still left? (zero based)
 tablerowloop.first	   # => is this the first iteration?
 tablerowloop.last	   # => is this the last iteration?
 tablerowloop.col	   # => index of column in the current row
 tablerowloop.col0	   # => index of column in the current row (zero based)
 tablerowloop.col_first    # => is this the first column in the row?
 tablerowloop.col_last     # => is this the last column in the row?

  {% tablerow item in items cols: 3 %}
    {% if col_first %}
      First column: {{ item.variable }}
    {% else %}
      Different column: {{ item.variable }}
    {% endif %}
  {% endtablerow %}