"Eager loading" of relations like Yii's "with" function

Question

Is there any way to "eagerly load" Craft element relations a la Yii's ActiveRelation "with" function?

http://www.yiiframework.com/doc/api/1.1/CActiveRecord#with-detail

This seems like a very handy way to request one big query instead of many small ones in cases where you know up front that you are going to be using all the relations.

** UPDATE **

Okay after experimenting with this, I guess my real question should have been, is there any way to do this kind of thing at the ElementCriteriaModel level, taking advantage of Craft relational fields.

For instance, I want to get a list of children of a Structure entry, along with all the assets in a field:

foreach ($entry->children->find() as $child) {
    // do something with $child->assetsField...
}

Is there any way to load those assets in one big query rather than individually for each child?

Answer 1

This feature has now made it into Craft core as of version 2.6.

See this link for documentation on the subject:
https://craftcms.com/docs/templating/eager-loading-elements

Answer 2

I've been thinking about ways to achieve this recently, and I've put together a basic proof-of-concept plugin for fetching one level of relations for a collection of elements, with no more than two extra queries for each element type.

One query to get the IDs of the related elements, and then another to actually fetch and return the elements with the ElementsService.

The plugin then matches those related elements back to the entries through a dynamically-added fetched() method.

Say you want to fetch all the Assets related through the mainImage and additionalImages fields, over a collection of product entries:

{% set entries = craft.entries.section('products').find %}
{% do craft.fetch.assets(entries, 'mainImage, additionalImages') %}

{% for entry in entries %}
    {% if entry.fetched('mainImage')|length %}
        <img src="{{ (entry.fetched('mainImage')|first).getUrl('large') }}"> 
    {% endif %}

    {% for image in entry.fetched('additionalImages') %}
        <img src="{{ image.getUrl('medium') }}"> 
    {% endfor %}
{% endfor %}

I wouldn't say it's necessarily production-ready yet, but I've thrown it up on Github - https://github.com/mdcpepper/fetch

Answer 3

Sure thing.

$groupRecord = FieldGroupRecord::model()->with('fields')->findById($groupId);

That will eager load the related data from the "fields" table with the "fieldgroups" table.