Use superagent for _changes feed request

This is an interim solution until fetch polyfill supports abort.

#34

package.json

@@ -22,7 +22,8 @@
     "react": "^15.0.2",
     "react-bootstrap": "^0.29.4",
     "react-dom": "^15.0.2",
-    "react-router": "^2.4.0"
+    "react-router": "^2.4.0",
+    "superagent": "^2.0.0-alpha.3"
   },
   "devDependencies": {
     "babel-core": "^6.8.0",

src/js/api/index.js

@@ -1,4 +1,5 @@
 import fetch from 'isomorphic-fetch'
+import request from 'superagent'
 import { serverApi } from '../app';
 import { makePath } from '../utils';
 
@@ -34,6 +35,39 @@ function _fetch(...args) {
   };
 }
 
+function _request(req) {
+  if (!req)
+    return null;
+
+  let rej;
+  let isCanceled = false;
+  const promise = new Promise((resolve, reject) => {
+    if (isCanceled)
+      reject({ isCanceled });
+    else {
+      rej = reject;
+      req.end((err, res) => {
+        if (err)
+          reject({ message: err.message, status: err.status });
+        else
+          resolve({ data: res.body, status: res.status });
+      });  
+    }  
+  });
+
+  return { 
+    promise,
+    cancel() {
+      if (!isCanceled) {
+        isCanceled = true;
+        req.abort();
+        if (rej) 
+          rej({ isCanceled });  
+      }
+    } 
+  };
+}
+
 export function fetchAllDatabases() {
   const path = makePath('_all_dbs');
   return _fetch(serverApi(path));
@@ -110,6 +144,14 @@ export function deleteDoc(db, docId, revId) {
 }
 
 export function fetchChangesFeed(db, params) {
+  const path = makePath(db, '_changes');
+  const req = request.post(serverApi(path))
+    .set('Content-Type', 'application/json')
+    .send(params);
+  return _request(req);
+}
+
+export function _fetchChangesFeed(db, params) {
   const path = makePath(db, '_changes');
   return _fetch(serverApi(path), {
     method: 'POST',

src/js/stores/AppStore.js

@@ -67,8 +67,6 @@ class AppStore extends Store {
   }
 
   setAlert(alert) {
-    if (alert)
-      debugger;
     this.setData(data => {
       return Object.assign({ }, data, { alert });
     });