Formatting query parameters that are arrays in Ember.Data - ember.js

Question

Let's say that I have an Ember.Data query I'd like to make:
this.store.find('items', {itemIds: [1,2,3]});
By default, Ember.Data creates a URL that looks like this:
items?itemIds%5B%5D=1&itemIds%5B%5D=2&itemIds%5B%5D=3
But the REST api I am connecting to wants it in this format:
items?itemIds=1&itemIds=2&itemIds=3
How do I achieve this adaptation?

Answer 1

Extend the RESTAdapter and override the ajax method and create the URL that you want to use based on the circumstances.
App.ItemsAdapter = DS.RESTAdapter.extend({
ajax: function(url, type, options){
if(myCircumstance){
var data = options.data;
delete options.data;
url = url + ......;
}
return this._super(url, type, options);
}
});
REST Adapter implementation: https://github.com/emberjs/data/blob/v1.0.0-beta.16.1/packages/ember-data/lib/adapters/rest-adapter.js

Answer 2

From what I see looking on the ember data code, you'd have to overwrite the RestAdapter's findQuery or ajax method, see http://emberjs.com/api/data/classes/DS.RESTAdapter.html#method_findMany (see https://github.com/emberjs/data/blob/v1.0.0-beta.16.1/packages/ember-data/lib/adapters/rest-adapter.js). Both are private, but the store expects the findQuery to be there (https://github.com/emberjs/data/blob/v1.0.0-beta.16.1/packages/ember-data/lib/system/store/finders.js#L137), so I wouldn't expect this behaviour to change soon.
If you use this for production, you'd better open a bug report to have this or something similar exposed as a public hook, as I cannot see one being there thus far.

Answer 3

#Kingpin2k's answer is the right direction, but the solution is even simpler. To create the query params, Ember Data simply yields the data object, wrapped in the options object, to the jQuery.ajax function.
Knowing that, we just need another query param serializer. By default, jQuery will serialize arrays the way TS described. You can change the way of serialization by overriding the $.param method. But luckily we don't even have too, because the $.param function has a second argument called traditional serialization. If set to true, the serialization will be like TS wanted*.
The jQuery.Ajax function also has the traditional flag to use the traditional style of param serialization. Combining this facts, you just need to set this flag yourself:
DS.RESTAdapter.extend({
ajax(url, type, options) {
if (options) {
options.traditional = true;
}
return this._super(...arguments);
}
});
P.S. If you use the JSONAPIAdapter, the trick is the same, because the JSONAPIAdapter extends the RESTAdapter.
*If you need another serialization, you need to override the $.param.