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There are two types of markup in liquid: Output and Tag. OutputHere is a simple example of Output: Hello {{name}}
Hello {{user.name}}
Hello {{ 'tobi' }}Advanced output: FiltersOutput 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 {{ 'tobi' | upcase }}
Hello tobi has {{ 'tobi' | length }} letters!
Hello {{ '*tobi*' | textilize | upcase }}
Hello {{ now | date: "%Y %h" }}
TagsTags are for the logic in your template. New tags are very easy to code and I hope to get many contributions to the standard tag library after releasing this code. Here is a list of currently supported tags: CommentsComment is the simplest tag. It just swallows content. Hi tobi {% comment %} you stink {% endcomment %}If / ElseIf else should be well known from any language imaginable. Liquid allows you to write simple expressions in the if. {% if user %}
Hi {{ user.name }}
{% endif %}
{% if user.name == 'tobi' %}
hi tobi
{% endif %}
{% if user.name != 'tobi' %}
hi non-tobi
{% endif %}
{% if user.creditcard == null %}
poor sob
{% endif %}
{% if user.payments == empty %}
you never paid !
{% endif %}
{% if user.age > 18 %}
Login here
{% else %}
Sorry, you are too young
{% endif %}Case StatementIf you need more than one condition you can use the Case Statement {% case condition %}
{% when 1 %}
hit 1
{% when 2 %}
hit 2
{% else %}
elseblock
{% endcase %} Example: {% case template %}
{% when 'label' %}
// {{ label.title }}
{% when 'product' %}
// {{ product.vendor | link_to_vendor }} / {{ product.title }}
{% else %}
// {{page_title}
{% endcase %}CycleOften you have to alternate between different colors or similar tasks. Liquid has build 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
oneIf 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
twoFor loopsLiquid allows for loops over collections {% for item in array %}
{{ item }}
{% endfor %} During every for loop there are following helper variables available for extra styling needs: 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 iternation? 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 1,2,3,4Variable AssignmentYou 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.
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In the last example, there's a stray apostrophe - currently, it's this: {% for t in collections.tags %}{% if t == 'freestyle %} Should be this: {% for t in collections.tags %}{% if t == freestyle %}
It seems that the variables are present only in the current scope ("global", if, loop, ..). I don't see this mentioned in the docs. It might be a good idea to mention it.
I'm just curious. If this is for RoR apps, why not just use rhtml?
I'm just curious. If this is for RoR apps, why not just use rhtml?
I like how it is used in Mephisto blog. But for writing RoR apps directly I'd rather stick with rhtml.
The whole point is that it is non-evaling. This means that the users only have access to the data you specify, and you don't have to worry about them running arbitrary queries or code.
Looping over a range of numbers, as documented above, doesn't appear to work.
{% for i in (1..5) %} {{ i }} {% endfor %} => Syntax Error in 'for loop' - Valid syntax: for [item] in [collection](1..5) is for ruby, not liquid
(1..5) works in liquid. You may need a checked out version
Still a mismatched apostrophe in the last example up there [-:
Also, how unlikely does it seem that all of the first four comments were on the 22nd of a month? d-:
Re: ranges, I was using the latest rubygem, which I hadn't realized is somewhat out of date. As Tobias mentioned, ranges are supported in the latest from source control.
What about using regular expressions to find out if a text string contains some pattern? Does this language support RE?
Please use the mailing list for such discussion. Liquid does not contain regular expression support at the moment but if it can be implemented in a secure way there is no reason to not accept a patch for it.
how to save a liquid tags file and how to execute the code
How do I get the index, first, last, etc variables in a for loop?