Ember-Cli: prepend a findAll() query with a prefix - ember.js

Question

In one of my routes I need to findAll() of user's Items, but instead of making the standard /items request it has to go to /my/items.
My current solution involves:
// routes/my/item.js
export default Ember.Route.extend({
model() {
this.store.unloadAll('item');
return Ember.$.getJSON('/my/items').then((payload) => {
this.store.pushPayload(payload);
return this.store.peekAll('item');
});
}
});
But unfortunately it's not ideal since it requires to unloadAll() items before making the request as to ensure that the model only returns freshly fetched records while unloading any cached.
A better solution will probably involve creating a custom adapter specifically for this route and overwriting either the findAll() method or urlForFindAll(), but I'm not sure how to properly create and import such custom adapter.
Just for testing I overwrote the default Item adapter and returned findAll('item') in the route's model, and everything worked, the request was prefixed with /my/:
// adapters/item.js
findAll: function(store, type, sinceToken, snapshotRecordArray) {
var query, url;
if (sinceToken) { query = { since: sinceToken }; }
// prefix url with `my` str
url = `my${this.buildURL(type.modelName, null, null, 'findAll')}`;
return this.ajax(url, 'GET', { data: query });
},
// routes/my/item.js
export default Ember.Route.extend({
model() {
return this.store.findAll('item');
}
});
..but that obviously overwrites all findAll() queries for this model, wherein I need to make a custom query only in this route.

Answer 1

This can be solved by using adapterOptions to pass options to the item's adapter using findAll:
1) In the route use adapterOption to pass prefix to the adapter:
return this.store.findAll('item', { adapterOptions: { prefix: 'my' } });
2) In ember-cli overwrite item's default adapter with ember g adapter item.
3) In the adapter overwrite the default findAll to prefix url if such option is passed:
// /app/adapters/item.js
import ApplicationAdapter from './application';
export default ApplicationAdapter.extend({
findAll: function(store, type, sinceToken, snapshotRecordArray) {
var query, url;
if (sinceToken) { query = { since: sinceToken }; }
let prefix = Ember.get(snapshotRecordArray, 'adapterOptions.prefix');
url = `${prefix || ''}${this.buildURL(type.modelName, null, null, 'findAll')}`;
return this.ajax(url, 'GET', { data: query });
},
});
4) Success, this.store.findAll('item', { adapterOptions: { prefix: 'my' } }); will now make a my/items instead of items!