Eager-Loading Assets in Matrix

Question

I've been using this example to eager load images, stored in an Assets field which is located in a Matrix field.

My query looks like this:

{% set entries = craft.entries.section('project')
.with(['projectMatrix.imageBlock:imageFile']) %}

Where projectMatrix is a Matrix field, imageBlock is a Matrix block type and imageFile is an Asset field inside imageBlock.

But how do I reference the that image in my templates?

{% for entry in entries %}

{% set matrixImage = entry.projectMatrix.type('imageBlock')[0].imageFile[0] ?? null %}

...

{% endfor %}

This is always be null, when eager loaded

Answer 1

The reason this doesn't work is because .type('image') won't work with eager loading. Eager loading removes the ability to use ElementCriteriaModel methods.

From the docs:

When the assets aren’t eager-loaded, entry.assetsField gives you an ElementCriteriaModel that is preconfigured to return the related assets once they’re requested (e.g. when first() is called).

However when the assets are eager-loaded, entry.assetsField gets overwritten with an array of the eager-loaded assets. So first(), find(), and other ElementCriteriaModel methods are not available. Instead you must stick to the standard array syntaxes.

As a work around, you could use a for loop to match only Matrix blocks of a particular type instead:

{% for block in entry.projectMatrix if block.type == 'imageBlock' %}
  {% set matrixImage = block.imageFile[0] %}
{% endfor %}

If you only want the first image block type:

{% for block in entry.projectMatrix if block.type == 'imageBlock' %}
  {% if loop.index == 1 %}
    {% set matrixImage = block.imageFile[0] %}
  {% endif %}
{% endfor %}