HubL Reference

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For loops

For loops can be used in HubL to iterate through sequences of objects. They will most commonly be used with rendering blog content in a listing format, but they can also be used to sort through other sequence variables.

For loops begin with a for statement and end with an endfor statement. Within the for statement, a single sequence item is named followed by "in" and then the name of the sequence. The code between the opening and closing for statements is printed with each iteration, and generally includes the the printed variable of the individual sequence item. Below is the basic syntax of a for loop:


        {% for item in items %}
            {{ item }}
        {% endfor %}
Below is a basic example that shows how to print a sequence of variable values into a list.

{% set languages = ['HTML', 'CSS', 'Javascript', 'Python', 'Ruby', 'PHP,', 'Java'] %}

<h1>Languages</h1>;
<ul>
{% for language in languages %}
<li>{{ language }}</li>
{% endfor %}
</ul>

<h1>Languages</h1>
<ul>
<li>HTML</li>
<li>CSS</li>
<li>Javascript</li>
<li>Python</li>
<li>Ruby</li>
<li>PHP</li>
<li>Java</li>
</ul>

Loop properties

As a loop iterates, you can use conditional logic to define the loop's behavior. The variable property loop.index keeps a count of the current number of the iterations of the loop. There are several other loop variable properties that count the iterations in different ways. These properties are described below:
VariableDescription
loop.index The current iteration of the loop. This variable starts counting at 1.
loop.index0 The current iteration of the loop. This variable starts counting at 0.
loop.revindex The number of iterations from the end of the loop. Counting down to 1.
loop.revindex0 The number of iterations from the end of the loop. Counting down to 1.
loop.first This variable evaluates to true, if it is the first iteration of the loop.
loop.last This variable evaluates to true, if it is the last iteration of the loop.
loop.length The number of items in the sequence.
loop.cycle A helper function to cycle between a list of sequences. See the explanation below.
loop.depth
Indicates how deep in deep in a recursive loop the rendering currently is. Starts at level 1
loop.depth0
Indicates how deep in deep in a recursive loop the rendering currently is. Starts at level 0

Below are some examples that use different loop variables. The following basic example, uses loop.index to keep a count that is printed with each iteration.


{% set loopy = ['Content', 'Social', 'Contacts', 'Reports'] %}
{% for app in loopy %}
    {{ loop.index }}. {{app}} <br>
{% endfor %}

1. Content <br>
2. Social <br>
3. Contacts <br>
4. Reports <br>

The next example uses uses conditional logic to check whether the length of the loop is divisibleby certain numbers. It then renders the width of the post-item div accordingly. The example uses the standard blog post loop and assumes that there are 6 posts in the loop.


{% for content in contents %}
{% if loop.length is divisibleby 4 %}
<div style="width:25%">Post content</div>

{% elif loop.length is divisibleby 3 %}
<div style="width:33.33332%">Post content</div>

{% else %}
<div style="width:50%">Post content</div>

{% endif %}
{% endfor %}
{% raw %}

<div style="width:33.33332%">Post content</div>
<div style="width:33.33332%">Post content</div>
<div style="width:33.33332%">Post content</div>
<div style="width:33.33332%">Post content</div>
<div style="width:33.33332%">Post content</div>
<div style="width:33.33332%">Post content</div>
<div style="width:33.33332%">Post content</div>

Nested loops

Loops can also be nested with loops. The child for loop will run with each iteration of the parent for loop. In the example below, a list of child items is printed in a nested <ul> within a <ul> of parent items.


{% set parents = ['Parent item 1', 'Parent item 2', 'Parent item 3'] %}
{% set children = ['Child item 1', 'Child item 2', 'Child item 3'] %}
<ul>
{% for parent in parents %}
<li>{{parent}}<ul>
    {% for child in children %}
    <li>{{child}}</li>
    {% endfor %}
    </ul>
</li>
{% endfor %}
</ul>

<ul>
<li>Parent item 1<ul>
    <li>Child item 1</li>
    <li>Child item 2</li>
    <li>Child item 3</li>
    </ul>
</li>

<li>Parent item 2<ul>
    <li>Child item 1</li>
    <li>Child item 2</li>
    <li>Child item 3</li>
    </ul>
</li>

<li>Parent item 3<ul>
    <li>Child item 1</li>
    <li>Child item 2</li>
    <li>Child item 3</li>
    </ul>
</li>
</ul>

cycle

The cycle tag can be used within a for loop to cycle through a series of string values and print them with each iteration. One of the most practical applications to this technique is applying alernating classes to your blog posts in a listing. This tag can be used on more than two values and will repeat the cycle if there are more loop iterations than cycle values. In the example below, a class of "odd" and "even" are applied to posts in a listing (the example assumes that there are 5 posts in the loop).  

Please note that there are no spaces between the comma separated cycle string values.


{% for content in contents %}
    <div class="post-item {% cycle 'odd','even' %}">Blog post content</div>
{% endfor %}

<div class="post-item odd">Blog post content</div>
<div class="post-item even">Blog post content</div>
<div class="post-item odd">Blog post content</div>
<div class="post-item even">Blog post content</div>
<div class="post-item odd">Blog post content</div>

Variables within loops

Any variables defined within loops are limited to the scope of that loop and cannot be called from outside of the loop.

You can call variables that are defined outside of a loop, from within a loop, but not the other way around.