Make / work under FastBoot

This commit adds a transparent cache called "fetcher" to prevent making 2 XHRs
(both from the frontend to the backend).

Author: kzys

app/controllers/index.js

@@ -1,31 +1,5 @@
 import Controller from '@ember/controller';
-import { computed } from '@ember/object';
-import { readOnly } from '@ember/object/computed';
-
-import ajax from 'ember-fetch/ajax';
-import { task } from 'ember-concurrency';
 
 export default Controller.extend({
-  model: readOnly('dataTask.lastSuccessful.value'),
-
-  hasData: computed('dataTask.{lastSuccessful,isRunning}', function() {
-    return this.get('dataTask.lastSuccessful') || !this.get('dataTask.isRunning');
-  }),
-
-  dataTask: task(function*() {
-    let data = yield ajax('/api/v1/summary');
-
-    addCrates(this.store, data.new_crates);
-    addCrates(this.store, data.most_downloaded);
-    addCrates(this.store, data.just_updated);
-    addCrates(this.store, data.most_recently_downloaded);
-
-    return data;
-  }).drop(),
+  hasData: true,
 });
-
-function addCrates(store, crates) {
-  for (let i = 0; i < crates.length; i++) {
-    crates[i] = store.push(store.normalize('crate', crates[i]));
-  }
-}

app/routes/index.js

@@ -1,6 +1,9 @@
 import Route from '@ember/routing/route';
+import { inject as service } from '@ember/service';
 
 export default Route.extend({
+  fetcher: service(),
+
   headTags() {
     return [
       {
@@ -13,8 +16,20 @@ export default Route.extend({
     ];
   },
 
-  setupController(controller) {
-    this.controllerFor('application').set('searchQuery', null);
-    controller.dataTask.perform();
+  model() {
+    return this.fetcher.ajax('/api/v1/summary');
+  },
+
+  afterModel(model, transition) {
+    addCrates(this.store, model.new_crates);
+    addCrates(this.store, model.most_downloaded);
+    addCrates(this.store, model.just_updated);
+    addCrates(this.store, model.most_recently_downloaded);
   },
 });
+
+function addCrates(store, crates) {
+  for (let i = 0; i < crates.length; i++) {
+    crates[i] = store.push(store.normalize('crate', crates[i]));
+  }
+}

app/services/fetcher.js

@@ -0,0 +1,31 @@
+import Service, { inject as service } from '@ember/service';
+import ajax from 'ember-fetch/ajax';
+
+export default Service.extend({
+  fastboot: service(),
+
+  ajax(url) {
+    let fastboot = this.fastboot;
+    let shoebox = this.fastboot.shoebox;
+    let cache = shoebox.retrieve('ajax-cache');
+    if (!cache) {
+      cache = {};
+    }
+
+    if (cache[url]) {
+      return cache[url];
+    }
+
+    return ajax(url).then(function(resp) {
+      if (shoebox && fastboot.isFastBoot) {
+        cache[url] = deepCopy(resp);
+        shoebox.put('ajax-cache', cache);
+      }
+      return resp;
+    });
+  },
+});
+
+function deepCopy(obj) {
+  return JSON.parse(JSON.stringify(obj));
+}