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Tag: "Set"

This tag stores a value into a variable for later use.

Node Information

Name Description
Tag Name set
End Tag endset or N/A (if you're creating an alias of an existing variable)
Rendering Immediately; no output
Parameter Description
Name The name of the variable you want to store.
Expression (Optional) The value to be stored.

The parameters and tags of this node depend on which mode you want to use:

  • Use {% set myVar %}...{% endset %} to render and store everything between the start and end tag into the variable.
  • Use {% set myVar someOtherVar.prop1.prop2 %} to evaluate and store an expression's result into the variable.

Example of render: {% set myVar %}hello{% endset %}

Example of evaluate: {% set myVar2 myVar|uppercase %}

When to use it

Useful when you have a certain calculation you want to re-use in multiple places without repeating yourself. For example you can compute only once the result of multiple filters applied in sequence to a variable, store that result and reuse it later.

This tag can be used in 2 ways:

  • Render: the content between the the set and endset tags is rendered immediately using the available context, and stored on the stack into a variable with the provided name.
  • Evaluate: the provided expression is evaluated and stored into a variable with the provided name. This is especially useful if you want to avoid the conversion of contents to a String value (which render mode always does).

Keep in mind that the variable is scoped, meaning that if you set a variable while (for example) inside a for loop, the set variable will not exist outside the scope of that for loop.

Usage example

// we start with 'x' and 'y' as empty variables
// 'items' is an array of integers in the context: [1, 3, 7]

// set value
{% set x %}hello{% endset %} 
{% set y %}world{% endset %}
// x = "hello", y = "world"

// Compute some complex expression once, and reuse it multiple times later
{% set greetings %}{{ x|uppercase }}, {{ y|titlecase }}{% endset %}
// greetings = "HELLO, World"

// set inside for loop
{% for item in items %}
  {% set x %}item #{{item}}{% endset %}
  // x = "item #...", y = "world"
  // greetings is still = "HELLO, World" (it isn't recomputed with new x)
{% endfor %}

// after for loop
// x = "hello", y = "world"

{{ greetings }}, {{ greetings }}, {{ greetings }}!
// HELLO World, HELLO World, HELLO World!

// Difference between render and evaluate:

{% set a %}{{items}}{% endset %}
{% set b items %}
// a = "[1, 3, 7]", b = [1, 3, 7]
// a is contains a string (the description of 'items')
// b contains an array, the same value as 'items'

// This will print every character in the string "[1, 3, 7]"
{% for item in a %}
	item = {{item}}
{% endfor %}

// This will print every item of the array [1, 3, 7]
{% for item in b %}
	item = {{item}}
{% endfor %}