Merge pull request #18 from truenorth/customize-pagination-params

Allow customization of pagination API

.travis.yml

@@ -19,6 +19,8 @@ env:
 
 matrix:
   fast_finish: true
+  allow_failures:
+    - env: EMBER_TRY_SCENARIO=ember-canary
 
 before_install:
   - export PATH=/usr/local/phantomjs-2.0.0/bin:$PATH

README.md

@@ -43,18 +43,67 @@ Now, whenever the `infinity-loader` is in view, it will send an action to the ro
 
 When the new records are loaded, they will automatically be pushed into the Model array.
 
-#### JSON Response
+## Advanced Usage
+
+### JSON Request/Response Customization
+
+By default, ember-infinity will send pagination parameters as part of a GET request as follows
+
+````
+/items?per_page=5&page=1
+```` 
 
-The response provided by your server should include the number of total pages.
+and will expect to recieve metadata in the response payload via a `total_pages` param in a `meta` object
 
-```json
-  { "meta": { "total_pages": 4 } }
+```js
+{
+  items: [
+    {id: 1, name: 'Test'},
+    {id: 2, name: 'Test 2'}
+  ],
+  meta: {
+    total_pages: 3
+  }
+}
 ```
 
-If your query returns 20 objects, and you're showing 6 per page, then the
-number of total pages would be 4.
+If you wish to customize some aspects of the JSON contract for pagination, you may do so via your routes. For example: 
 
-## Advanced Usage
+```js
+import Ember from 'ember';
+import InfinityRoute from "ember-infinity/mixins/route";
+
+export default Ember.Route.extend(InfinityRoute, {
+
+  perPageParam: "per",              // instead of "per_page"
+  pageParam: "pg",                  // instead of "page"
+  totalPagesParam: "meta.total",    // instead of "meta.total_pages"
+
+  model() {
+    /* Load pages of the Product Model, starting from page 1, in groups of 12. */
+    return this.infinityModel("product", { perPage: 12, startingPage: 1 });
+  }
+});
+```
+
+This will result in request query params being sent out as follows
+
+````
+/items?per=5&pg=1
+```` 
+
+and ember-infinity will be set up to parse the total number of pages from a JSON response like this:
+
+```js
+{
+  items: [
+    ...
+  ],
+  meta: {
+    total: 3
+  }
+}
+```
 
 ### infinityModel
 

addon/mixins/route.js

@@ -68,6 +68,30 @@ export default Ember.Mixin.create({
   */
   _modelPath: 'controller.model',
 
+  /**
+   * Name of the "per page" param in the
+   * resource request payload
+   * @type {String}
+   * @default  "per_page"
+   */
+  perPageParam: 'per_page',
+
+  /**
+   * Name of the "page" param in the
+   * resource request payload
+   * @type {String}
+   * @default "page"
+   */
+  pageParam: 'page',
+
+  /**
+   * Path of the "total pages" param in
+   * the HTTP response
+   * @type {String}
+   * @default  "meta.total_pages"
+   */
+  totalPagesParam: 'meta.total_pages',
+
   /**
     @private
     @property _canLoadMore
@@ -113,18 +137,22 @@ export default Ember.Mixin.create({
     this.set('_modelPath', modelPath);
     this.set('_extraParams', options);
 
-    var params = Ember.merge({ page: startingPage, per_page: perPage }, options);
+    var requestPayloadBase = {};
+    requestPayloadBase[this.get('perPageParam')] = perPage;
+    requestPayloadBase[this.get('pageParam')] = startingPage;
+
+    var params = Ember.merge(requestPayloadBase, options);
     var promise = this.store.find(modelName, params);
 
     promise.then(
-      function(infinityModel) {
-        var totalPages = infinityModel.get('meta.total_pages');
+      infinityModel => {
+        var totalPages = infinityModel.get(this.get('totalPagesParam'));
         _this.set('_currentPage', startingPage);
         _this.set('_totalPages', totalPages);
         infinityModel.set('reachedInfinity', !_this.get('_canLoadMore'));
         Ember.run.scheduleOnce('afterRender', _this, 'infinityModelUpdated', { lastPageLoaded: startingPage, totalPages: totalPages, newObjects: infinityModel });
       },
-      function() {
+      () => {
         throw new Ember.Error("Could not fetch Infinity Model. Please check your serverside configuration.");
       }
     );

tests/unit/mixins/route-test.js

@@ -89,6 +89,71 @@ test('it sets state before it reaches the end', function(assert) {
   assert.ok(!model.get('reachedInfinity'), 'Should not reach infinity');
 });
 
+test('it allows customizations of request params', assert => {
+  var RouteObject = Ember.Route.extend(RouteMixin, {
+    perPageParam: 'per',
+    pageParam: 'p',
+    model() {
+      return this.infinityModel('item');
+    }
+  });
+  var route = RouteObject.create();
+
+  var dummyStore = {
+    find(modelType, findQuery) {
+      assert.deepEqual(findQuery, {per: 25, p: 1});
+      return new Ember.RSVP.Promise(resolve => {
+        Ember.run(this, resolve, Ember.Object.create({
+          items: []
+        }));
+      });
+    }
+  };
+
+  route.store = dummyStore;
+
+  var model;
+  Ember.run(function() {
+    route.model().then(function(result) {
+      model = result;
+    });
+  });
+});
+
+test('it allows customizations of meta parsing params', assert => {
+  var RouteObject = Ember.Route.extend(RouteMixin, {
+    totalPagesParam: 'pagination.total',
+    model() {
+      return this.infinityModel('item');
+    }
+  });
+  var route = RouteObject.create();
+
+  var dummyStore = {
+    find(modelType, findQuery) {
+      return new Ember.RSVP.Promise(resolve => {
+        Ember.run(this, resolve, Ember.Object.create({
+          items: [{id: 1, name: 'Walter White'}],
+          pagination: {
+            total: 22
+          }
+        }));
+      });
+    }
+  };
+
+  route.store = dummyStore;
+
+  var model;
+  Ember.run(function() {
+    route.model().then(function(result) {
+      model = result;
+    });
+  });
+
+  assert.equal(22, route.get('_totalPages'));
+});
+
 test('it sets state  when it reaches the end', function(assert) {
 
   var RouteObject = Ember.Route.extend(RouteMixin, {