Overview
serviceminder uses DotLiquid as a multi-purpose scripting language for dynamically generating print and email template content. It is an adaptation of the Liquid scripting language used by Shopify, with a few notable differences which we attempt to document below.
For a full list of properties accessible via DotLiquid, please visit: https://serviceminder.com/support/dotliquid
This article will review:
Comment
Allows you to leave un-rendered code inside a Liquid template. Any text within the opening and closing comment blocks will not be printed, and any Liquid code within will not be executed.
Input
Anything you put between {% comment %} and {% endcomment %} tags
is turned into a comment.
Output
Anything you put between tags is turned into a comment.
Control Flow
Control flow tags can change the information Liquid shows using programming logic.
if
Executes a block of code only if a certain condition is true.
Input
{% if product.title == "Awesome Shoes" %}
These shoes are awesome!
{% endif %}
Output
These shoes are awesome!
unless
The opposite of if – executes a block of code only if a certain condition is not met.
Input
{% unless product.title == "Awesome Shoes" %}
These shoes are not awesome.
{% endunless %}
Output
These shoes are not awesome.
This would be the equivalent of doing the following:
{% if product.title != "Awesome Shoes" %}
These shoes are not awesome.
{% endif %}
elsif / else
Adds more conditions within an if or unless block.
Input
{% if customer.name == "kevin" %}
Hey Kevin!
{% elsif customer.name == "anonymous" %}
Hey Anonymous!
{% else %}
Hi Stranger!
{% endif %}
Output
Hey Anonymous!
case/when
Creates a switch statement to compare a variable with different values. case initializes the switch statement, and when compares its values.
Input
{% assign handle = "cake" %}
{% case handle %}
{% when "cake" %}
This is a cake
{% when "cookie" %}
This is a cookie
{% else %}
This is not a cake nor a cookie
{% endcase %}
Output
This is a cake
Iteration
Iteration tags run blocks of code repeatedly.
for
Repeatedly executes a block of code. For a full list of attributes available within a for loop, see forloop (object).
Input
{% for product in collection.products %}
{{ product.title }}
{% endfor %}
Output
hat shirt pants
else
Specifies a fallback case for a for loop which will run if the loop has zero length.
Input
{% for product in collection.products %}
{{ product.title }}
{% else %}
The collection is empty.
{% endfor %}
Output
The collection is empty.
break
Causes the loop to stop iterating when it encounters the break tag.
Input
{% for i in (1..5) %}
{% if i == 4 %}
{% break %}
{% else %}
{{ i }}
{% endif %}
{% endfor %}
Output
1 2 3
continue
Causes the loop to skip the current iteration when it encounters the continue tag.
Input
{% for i in (1..5) %}
{% if i == 4 %}
{% continue %}
{% else %}
{{ i }}
{% endif %}
{% endfor %}
Output
1 2 3 5
for (parameters)
limit
Limits the loop to the specified number of iterations.
Input
{% for item in array limit:2 %}
{{ item }}
{% endfor %}
Output
1 2
offset
Begins the loop at the specified index.
Input
{% for item in array offset:2 %}
{{ item }}
{% endfor %}
Output
3 4 5 6
range
Defines a range of numbers to loop through. The range can be defined by both literal and variable numbers.
Input
{% for i in (3..5) %}
{{ i }}
{% endfor %}
{% assign num = 4 %}
{% for i in (1..num) %}
{{ i }}
{% endfor %}
Output
3 4 5 1 2 3 4
reversed
Reverses the order of the loop. Note that this flag’s spelling is different from the filter reverse.
Input
{% for item in array reversed %}
{{ item }}
{% endfor %}
Output
6 5 4 3 2 1
cycle
Loops through a group of strings and prints them in the order that they were passed as arguments. Each time cycle is called, the next string argument is printed.
cycle must be used within a for loop block.
Input
{% cycle "one", "two", "three" %}
{% cycle "one", "two", "three" %}
{% cycle "one", "two", "three" %}
{% cycle "one", "two", "three" %}
Output
one two three one
Uses for cycle include:
- applying odd/even classes to rows in a table
- applying a unique class to the last product thumbnail in a row
cycle (parameters)
cycle accepts a “cycle group” parameter in cases where you need multiple cycle blocks in one template. If no name is supplied for the cycle group, then it is assumed that multiple calls with the same parameters are one group.
Input
{% cycle "first": "one", "two", "three" %}
{% cycle "second": "one", "two", "three" %}
{% cycle "second": "one", "two", "three" %}
{% cycle "first": "one", "two", "three" %}
Output
one one two two
tablerow
Generates an HTML table. Must be wrapped in opening <table> and closing </table> HTML tags.
Input
{% tablerow product in collection.products %}
{{ product.title }}
{% endtablerow %}Output
Cool Shirt | Alien Poster | Batman Poster | Bullseye Shirt | Another Classic Vinyl | Awesome Jeans |
tablerow (parameters)
cols
Defines how many columns the tables should have.
Input
{% tablerow product in collection.products cols:2 %}
{{ product.title }}
{% endtablerow %}
Output
| Cool Shirt | Alien Poster |
| Batman Poster | Bullseye Shirt |
| Another Classic Vinyl | Awesome Jeans |
limit
Exits the tablerow after a specific index.
{% tablerow product in collection.products cols:2 limit:3 %}
{{ product.title }}
{% endtablerow %}
offset
Starts the tablerow after a specific index.
{% tablerow product in collection.products cols:2 offset:3 %}
{{ product.title }}
{% endtablerow %}
range
Defines a range of numbers to loop through. The range can be defined by both literal and variable numbers.
{% assign num = 4 %}
{% tablerow i in (1..num) %}
{{ i }}
{% endtablerow %}Raw
Raw temporarily disables tag processing. This is useful for generating content (eg, Mustache, Handlebars) which uses conflicting syntax.
Input
{% raw %}
In Handlebars, {{ this }} will be HTML-escaped, but
{{{ that }}} will not.
{% endraw %}
Output
In Handlebars, {{ this }} will be HTML-escaped, but {{{ that }}} will not.
Variable
Variable tags create new Liquid variables.
assign
Creates a new variable.
Input
{% assign my_variable = false %}
{% if my_variable != true %}
This statement is valid.
{% endif %}
Output
This statement is valid.
Wrap a variable value in quotations " to save it as a string.
Input
{% assign foo = "bar" %}
{{ foo }}
Output
bar
capture
Captures the string inside of the opening and closing tags and assigns it to a variable. Variables created through capture are strings.
Input
{% capture my_variable %}I am being captured.{% endcapture %}
{{ my_variable }}
Output
I am being captured.
Using capture, you can create complex strings using other variables created with assign:
Input
{% assign favorite_food = "pizza" %}
{% assign age = 35 %}
{% capture about_me %}
I am {{ age }} and my favorite food is {{ favorite_food }}.
{% endcapture %}
{{ about_me }}
Output
I am 35 and my favourite food is pizza.
increment
Creates a new number variable, and increases its value by one every time it is called. The initial value is 0.
Input
{% increment my_counter %}
{% increment my_counter %}
{% increment my_counter %}
Output
0 1 2
Variables created through the increment tag are independent from variables created through assign or capture.
In the example below, a variable named “var” is created through assign. The increment tag is then used several times on a variable with the same name. Note that the increment tag does not affect the value of “var” that was created through assign.
Input
{% assign var = 10 %}
{% increment var %}
{% increment var %}
{% increment var %}
{{ var }}
Output
0 1 2 10
decrement
Creates a new number variable, and decreases its value by one every time it is called. The initial value is -1.
Input
{% decrement variable %}
{% decrement variable %}
{% decrement variable %}
Output
-1 -2 -3
Like increment, variables declared inside decrement are independent from variables created through assign or capture.
