#23(feat): add fetchMultiple flag to resolve the same link multiple times

Author: guylabs

README.md

@@ -373,10 +373,21 @@ SpringDataRestAdapter.process(response, 'anotherLink', true).then(function(proce
 });
 ```
 
-Now the response of the `anotherLink` will be processed the same way as the main response was processed. But *be aware* when setting the recursive flag to true, because when your reponses of the links contain the same link name again, then it will end up in a infinite loop.
+Now the response of the `anotherLink` will be processed the same way as the main response was processed. But *be aware* when setting the recursive flag to true, because when your responses of the links contain the same link name again, then it will end up in a infinite loop.
 
 It will not fetch the `self` link as this would make no sense because the data is already in the response. The `self` key is also configurable. Read more [here](#configuration-of-the-springdatarestadapter).
 
+As a last configuration option you are able to set the fourth parameter called `fetchMultiple` of the `process` method which is used to define if a link is fetched multiple times if the same link is contained in multiple links and you want to resolve each one of them. The drawback
+is that it won't cache the responses in any way. So if you enable this then multiple network calls will be made. Here an example:
+
+```javascript
+SpringDataRestAdapter.process(response, 'anotherLink', true, true).then(function(processedResponse) {
+  ...
+});
+```
+
+:warning: If you set the `fetchMultiple` to `true` you could end up in an infinite loop if you have circular dependencies in your `_links`.
+
 #### Fetch multiple or all links
 
 If you want to fetch multiple links then you are able to add an array of strings with the given link names:
@@ -552,7 +563,7 @@ myApp.config(function (SpringDataRestAdapterProvider) {
     SpringDataRestAdapterProvider.config({
         fetchFunction: function (url, key, data, fetchLinkNames, recursive) {
             var $http = angular.injector(['ng']).get('$http');
-    
+
             $http.get('/rest/endpoint').then(function (responseData) {
                 console.log(responseData);
             })

dist/angular-spring-data-rest.js

@@ -100,9 +100,11 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
              * @param {object} data the data object reference in which the response is stored
              * @param {[string]|string} fetchLinkNames the fetch link names to allow to process the fetched response
              * @param {boolean} recursive true if the fetched response should be processed recursively with the
+             * @param {boolean} fetchMultiple true if multiple same link names should be resolved. ATTENTION: this could lead to
+             * an infinite loop when you have circular dependencies between the links.
              * adapter, false otherwise
              */
-            function fetchFunction(url, key, data, fetchLinkNames, recursive) {
+            function fetchFunction(url, key, data, fetchLinkNames, recursive, fetchMultiple) {
                 if (config.fetchFunction == undefined) {
                     var promisesArray = [];
 
@@ -111,7 +113,7 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
 
                             // wrap the response again with the adapter and return the promise
                             if (recursive) {
-                                return processData(responseData.data, fetchLinkNames, true).then(function (processedData) {
+                                return processData(responseData.data, fetchLinkNames, true, fetchMultiple).then(function (processedData) {
                                     data[key] = processedData;
                                 });
                             } else {
@@ -129,7 +131,7 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
                     // wait for all promises to be resolved and return a new promise
                     return $injector.get("$q").all(promisesArray);
                 } else {
-                    return config.fetchFunction(url, key, data, fetchLinkNames, recursive);
+                    return config.fetchFunction(url, key, data, fetchLinkNames, recursive, fetchMultiple);
                 }
             }
 
@@ -142,9 +144,11 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
              * 'fetchAllLinkNamesKey' key from the config object to fetch all links except the 'self' key.
              * @param {boolean} recursive true if the automatically fetched response should be processed recursively with the
              * adapter, false otherwise
+             * @param {boolean} fetchMultiple true if multiple same link names should be resolved. ATTENTION: this could lead to
+             * an infinite loop when you have circular dependencies between the links.
              * @returns {object} the processed JSON data
              */
-            var processData = function processDataFunction(promiseOrData, fetchLinkNames, recursive) {
+            var processData = function processDataFunction(promiseOrData, fetchLinkNames, recursive, fetchMultiple) {
 
                 // convert the given promise or data to a $q promise
                 return $injector.get("$q").when(promiseOrData).then(function (data) {
@@ -274,12 +278,12 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
                                     // 2. the all link names key is given then fetch the link
                                     // 3. the given key is equal
                                     // 4. the given key is inside the array
-                                    if (linkMap[self].indexOf(linkName) < 0 &&
+                                    if ((fetchMultiple || linkMap[self].indexOf(linkName) < 0) &&
                                         (fetchLinkNames == config.fetchAllKey ||
                                         (typeof fetchLinkNames === "string" && linkName == fetchLinkNames) ||
                                         (fetchLinkNames instanceof Array && fetchLinkNames.indexOf(linkName) >= 0))) {
                                         promisesArray.push(fetchFunction(getProcessedUrl(data, linkName), linkName,
-                                            processedData, fetchLinkNames, recursive));
+                                            processedData, fetchLinkNames, recursive, fetchMultiple));
                                         linkMap[self].push(linkName);
                                     }
                                 }
@@ -307,7 +311,7 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
                                 var processedDataArrayPromise;
                                 angular.forEach(value, function (arrayValue, arrayKey) {
                                     if (angular.isObject(arrayValue)) {
-                                        processedDataArrayPromise = processDataFunction({data: arrayValue}, fetchLinkNames, recursive).then(function (processedResponseData) {
+                                        processedDataArrayPromise = processDataFunction({data: arrayValue}, fetchLinkNames, recursive, fetchMultiple).then(function (processedResponseData) {
                                             processedDataArray[arrayKey] = processedResponseData;
                                         });
                                         promisesArray.push(processedDataArrayPromise);
@@ -324,7 +328,7 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
                                 }
                             } else if (angular.isObject(value)) {
                                 // single objects are processed directly
-                                promisesArray.push(processDataFunction({data: value}, fetchLinkNames, recursive).then(function (processedResponseData) {
+                                promisesArray.push(processDataFunction({data: value}, fetchLinkNames, recursive, fetchMultiple).then(function (processedResponseData) {
                                     processedData[config.embeddedNewKey][key] = processedResponseData;
                                 }));
                             }
@@ -378,9 +382,9 @@ angular.module("spring-data-rest").provider("SpringDataRestAdapter", function ()
             // empty the map and
             // return an object with the processData function
             return {
-                process: function(promiseOrData, fetchLinkNames, recursive) {
+                process: function (promiseOrData, fetchLinkNames, recursive, fetchMultiple) {
                     linkMap = {};
-                    return processData(promiseOrData, fetchLinkNames, recursive);
+                    return processData(promiseOrData, fetchLinkNames, recursive, fetchMultiple);
                 }
             };
         }]