GUAC-586: Invoke REST service functions across multiple data sources using dataSourceService.apply().

guacamole/src/main/webapp/app/rest/services/dataSourceService.js

@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2015 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * Service which contains all REST API response caches.
+ */
+angular.module('rest').factory('dataSourceService', ['$injector',
+        function dataSourceService($injector) {
+
+    // Required services
+    var $q = $injector.get('$q');
+
+    // Service containing all caches
+    var service = {};
+
+    /**
+     * Invokes the given function once for each of the given data sources,
+     * passing that data source as the first argument to each invocation,
+     * followed by any additional arguments passed to apply(). The results of
+     * each invocation are aggregated into a map by data source identifier,
+     * and handled through a single promise which is resolved or rejected
+     * depending on the success/failure of each resulting REST call. Any error
+     * results in rejection of the entire apply() operation, except 404 ("NOT
+     * FOUND") errors, which are ignored.
+     *
+     * @param {Function} fn
+     *     The function to call for each of the given data sources. The data
+     *     source identifier will be given as the first argument, followed by
+     *     the rest of the arguments given to apply(), in order. The function
+     *     must return a Promise which is resolved or rejected depending on the
+     *     result of the REST call.
+     *
+     * @param {String[]} dataSources
+     *     The array or data source identifiers against which the given
+     *     function should be called.
+     *
+     * @param {...*} args
+     *     Any additional arguments to pass to the given function each time it
+     *     is called.
+     *
+     * @returns {Promise.<Object.<String, *>>}
+     *     A Promise which resolves with a map of data source identifier to
+     *     corresponding result. The result will be the exact object or value
+     *     provided as the resolution to the Promise returned by calls to the
+     *     given function.
+     */
+    service.apply = function apply(fn, dataSources) {
+
+        var deferred = $q.defer();
+
+        var requests = [];
+        var results = {};
+
+        // Build array of arguments to pass to the given function
+        var args = [];
+        for (var i = 2; i < arguments.length; i++)
+            args.push(arguments[i]);
+
+        // Retrieve the root group from all data sources
+        angular.forEach(dataSources, function invokeAgainstDataSource(dataSource) {
+
+            // Add promise to list of pending requests
+            var deferredRequest = $q.defer();
+            requests.push(deferredRequest.promise);
+
+            // Retrieve root group from data source
+            fn.apply(this, [dataSource].concat(args))
+
+            // Store result on success
+            .then(function immediateRequestSucceeded(response) {
+                results[dataSource] = response.data;
+                deferredRequest.resolve();
+            },
+
+            // Fail on any errors (except "NOT FOUND")
+            function immediateRequestFailed(response) {
+
+                // Ignore "NOT FOUND" errors
+                if (response.status === 404)
+                    deferredRequest.resolve();
+
+                // Explicitly abort for all other errors
+                else
+                    deferredRequest.reject(response);
+
+            });
+
+        });
+
+        // Resolve if all requests succeed
+        $q.all(requests).then(function requestsSucceeded() {
+            deferred.resolve(results);
+        },
+
+        // Reject if at least one request fails
+        function requestFailed(response) {
+            deferred.reject(response);
+        });
+
+        return deferred.promise;
+
+    };
+
+    return service;
+
+}]);