Working in Laravel, I needed to loop through an array and know whether the current loop was odd or even row. To do this add the expression to your Twig file:
{% set direction = loop.index0 is odd ? 'left' : 'right' %}In the call above, the variable direction is set to either left or right depending on the value of the position of the loop row (loop.index0). I then used the left or right value in a div class adding to a series of tailwind css definitions. Such as text-{{ direction }}
The full div tag in this instance was:
<div class="font-light block text-5xl py-5 px-10 text-{{ direction }} tracking-wider text-white">{{ item.title }}</div>The expression odd returns true if the given number is odd:
{{ var is odd }}Therefore in the set direction call above, when odd is true the value of direction will be left.
Other twig set calls
{% set foo = 'bar' %}After the set call, the foo variable is available in the template like any other ones:
{# displays bar #}
{{ foo }}
The assigned value can be any valid Twig expression:
{% set foo = [1, 2] %}
{% set foo = {'foo': 'bar'} %}
{% set foo = 'foo' ~ 'bar' %}Several variables can be assigned in one block:
{% set foo, bar = 'foo', 'bar' %}
The above call is equivalent to writing:
{% set foo = 'foo' %}
{% set bar = 'bar' %}
The set tag can also be used to ‘capture’ chunks of text:
{% set foo %}
<div id="pagination">
...
</div>
{% endset %}If you enable automatic output escaping, Twig will only consider the content to be safe when capturing chunks of text.
Note, that loops are scoped in Twig; therefore a variable declared inside a for loop is not accessible outside the loop itself:
{% for item in list %}
{% set foo = item %}
{% endfor %}{# foo is NOT available #}
If you want to access the variable, just declare it before the loop:
{% set foo = "" %}
{% for item in list %}
{% set foo = item %}
{% endfor %}{# foo is available #}