Publish Vulpes Preview 15 sources for desktop, Android and Tundra

Share Gaia assets and adapters, keep private profiles and development documents local, and update both public READMEs.

gaia/shared/js/contacts/import/utilities/config.js

@@ -0,0 +1,102 @@
+'use strict';
+/* global Promise */
+
+var utils = window.utils || {};
+
+if (typeof utils.config === 'undefined') {
+  (function() {
+    var configs = {};
+    var initializing = {};
+    var initialized = {};
+
+    var EVENT_INITIALIZED = 'config_initialized';
+
+    utils.config = utils.config || {};
+
+    utils.config.reset = function() {
+      configs = {};
+      initializing = {};
+      initialized = {};
+    };
+
+    function onLoad(xhr, file, resolveCb) {
+      configs[file] = xhr.response;
+
+      delete initializing[file];
+      initialized[file] = true;
+
+      document.dispatchEvent(new CustomEvent(EVENT_INITIALIZED, {
+        detail: {
+          file: file,
+          success: true
+        }
+      }));
+      resolveCb(configs[file]);
+    }
+
+    utils.config.load = function(file) {
+      return new Promise(function(resolve, reject) {
+        var isInitialized = initialized[file];
+        if (isInitialized === true) {
+          resolve(configs[file]);
+          return;
+        }
+
+        var isInitializing = initializing[file];
+        if (isInitializing) {
+          var handler = function(expectedFile, e) {
+            document.removeEventListener(EVENT_INITIALIZED, handler);
+            var file = e.detail.file;
+            if (expectedFile !== file) {
+              return;
+            }
+
+            if (e.detail.success) {
+              resolve(configs[file]);
+            }
+            else {
+              reject();
+            }
+          }.bind(null, file);
+
+          document.addEventListener(EVENT_INITIALIZED, handler);
+          return;
+        }
+
+        initializing[file] = true;
+
+        var xhr = new XMLHttpRequest();
+        xhr.open('GET', file, true);
+        xhr.responseType = 'json';
+
+        xhr.onload = function() {
+          var resolvedCb = resolve;
+          if (xhr.status !== 200) {
+            resolvedCb = reject;
+          }
+          onLoad(xhr, file, resolvedCb);
+        };
+
+        xhr.onerror = function() {
+          document.dispatchEvent(new CustomEvent(EVENT_INITIALIZED, {
+            detail: {
+              file: file,
+              success: false
+            }
+          }));
+          delete initializing[file];
+          reject(xhr.error);
+        };
+
+        // If there is any exception we consider the file does not exist
+        try {
+          xhr.send(null);
+        }
+        catch(e) {
+          console.error('Error while loading config file: ', e.message);
+          onLoad({ status: 404 }, file, reject);
+        }
+      });
+    };
+  })();
+}