WP-API JS client can't use getCategories for models returned by collections

[jesseenterprises]

Migrating report from ​https://github.com/WP-API/client-js/issues/144

---

If I do this:

var postsCollection = new wp.api.collections.Posts();
postsCollection.fetch();

I'm only seeing the category id returned in the attributes object for each post.

Is there a way to include all category data there? Or from that point, when I'm looping over postsCollection, how do I get the category data for each post?

I tried doing this:

postsCollection.each( function( post ) {
    post.getCategories().done( function( postCategories ) {
        // ... do something with the categories.
        // The new post has an single Category: Uncategorized
        console.log( postCategories[0].name );
        // response -> "Uncategorized"
    });
});

But this is giving me post.getCategories is not a function.

Any insight here? Basically I'm just trying to find out how to loop over posts AND include their categories.

[jesseenterprises]

39070.diff​ fixes an issue where models automatically created as children of fetched collections didn't have appropriate mixin methods, like .getCategories, applied. This is resolved by defining the model property of fetched collections as a function returning an instantiated model, instead of a static model prototype.

[adamsilverstein]

Looks good @jesseenterprises, thanks! I'll test this out.

[helen]

Milestoning for investigation.

[adamsilverstein]

I added some additional tests for this in ​https://github.com/WP-API/client-js/pull/148/files. I am still working on getting these tests integrated into the WordPress core testing suit. I did verify they fail before the attached patch and pass after it.

[adamsilverstein]

In 39603:

WP-API: JavaScript client - fix setup of models used by wp.api.collections objects.

Correct setup for the model attribute of wp.api.collections objects. Set the collection model as a function that returns a new model of the underlying type, instead of setting it as the model prototype. Fixes an issue where models for fetched collections weren't set up properly and didn't have the expected mixin methods such as getCategories available.

Props jesseenterprises.
Fixes #39070.

[adamsilverstein]

In 39604:

WP-API: JavaScript client - fix setup of models used by wp.api.collections objects.

Correct setup for the model attribute of wp.api.collections objects. Set the collection model as a function that returns a new model of the underlying type, instead of setting it as the model prototype. Fixes an issue where models for fetched collections weren't set up properly and didn't have the expected mixin methods such as getCategories available.

Props jesseenterprises.
Merges [39603] to the 4.7 branch.
Fixes #39070.