wilford's changes to serve cached data and then fetch from server if needed / specified

Author: Shyam Seshadri

src/Resource.js

@@ -94,6 +94,8 @@ ResourceFactory.prototype = {
           function(status, response) {
             if (status == 200) {
               if (action.isArray) {
+                if (action.cacheThenRetrieve)
+                  value = [];
                 foreach(response, function(item){
                   value.push(new Resource(item));
                 });
@@ -104,7 +106,8 @@ ResourceFactory.prototype = {
             } else {
               throw {status: status, response:response, message: status + ": " + response};
             }
-          }
+          },
+          action.cacheThenRetrieve
         );
         return value;
       };
@@ -135,4 +138,3 @@ ResourceFactory.prototype = {
     return Resource;
   }
 };
-

src/services.js

@@ -313,7 +313,7 @@ angularService('$xhr.bulk', function($xhr, $error, $log){
 
 angularService('$xhr.cache', function($xhr){
   var inflight = {}, self = this;;
-  function cache(method, url, post, callback){
+  function cache(method, url, post, callback, cacheThenRetrieve){
     if (isFunction(post)) {
       callback = post;
       post = null;
@@ -322,7 +322,11 @@ angularService('$xhr.cache', function($xhr){
       var data;
       if (data = cache.data[url]) {
         callback(200, copy(data.value));
-      } else if (data = inflight[url]) {
+        if (!cacheThenRetrieve)
+          return;
+      }
+
+      if (data = inflight[url]) {
         data.callbacks.push(callback);
       } else {
         inflight[url] = {callbacks: [callback]};
@@ -340,6 +344,7 @@ angularService('$xhr.cache', function($xhr){
           });
         });
       }
+
     } else {
       cache.data = {};
       cache.delegate(method, url, post, callback);

test/servicesSpec.js

@@ -306,12 +306,28 @@ describe("service", function(){
         cache('GET', '/url', null, callback);
         xhr.flush();
         expect(log).toEqual('"first";"first";');
+        cache('GET', '/url', null, callback, false);
+        xhr.flush();
+        expect(log).toEqual('"first";"first";"first";');
+      });
+
+      it('should first return cache request, then return server request', function(){
+        xhr.expectGET('/url').respond('first');
+        cache('GET', '/url', null, callback, true);
+        xhr.flush();
+        xhr.expectGET('/url').respond('ERROR');
+        cache('GET', '/url', null, callback, true);
+        expect(log).toEqual('"first";"first";');
+        xhr.flush();
+        expect(log).toEqual('"first";"first";"ERROR";');
       });
 
       it('should serve requests from cache', function(){
         cache.data.url = {value:'123'};
         cache('GET', 'url', null, callback);
         expect(log).toEqual('"123";');
+        cache('GET', 'url', null, callback, false);
+        expect(log).toEqual('"123";"123";');
       });
 
       it('should keep track of in flight requests and request only once', function(){