[CCSDK-28] populated the seed code for dgbuilder

[ccsdk/distribution.git] / dgbuilder / red / settings.js

diff --git a/dgbuilder/red/settings.js b/dgbuilder/red/settings.js
new file mode 100644 (file)
index 0000000..4994953
--- /dev/null
+++ b/dgbuilder/red/settings.js
@@ -0,0 +1,84 @@
+/**
+ * Copyright 2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+var when = require("when");
+
+var assert = require("assert");
+
+var userSettings = null;
+var globalSettings = null;
+var storage = null;
+
+var persistentSettings = {
+    init: function(settings) {
+        userSettings = settings;
+        
+        for (var i in settings) {
+            if (settings.hasOwnProperty(i)) {
+                (function() {
+                    var j = i;
+                    persistentSettings.__defineGetter__(j,function() { return userSettings[j]; });
+                    persistentSettings.__defineSetter__(j,function() { throw new Error("Property '"+i+"' is read-only"); });
+                })();
+            }
+        }
+        globalSettings = null;
+    },
+    load: function(_storage) {
+        storage = _storage;
+        return storage.getSettings().then(function(_settings) {
+            globalSettings = _settings;
+        });
+    },
+    get: function(prop) {
+        if (userSettings.hasOwnProperty(prop)) {
+            return userSettings[prop];
+        }
+        if (globalSettings === null) {
+            throw new Error("Settings not available");
+        }
+        return globalSettings[prop];
+    },
+    
+    set: function(prop,value) {
+        if (userSettings.hasOwnProperty(prop)) {
+            throw new Error("Property '"+prop+"' is read-only");
+        }
+        if (globalSettings === null) {
+            throw new Error("Settings not available");
+        }
+        var current = globalSettings[prop];
+        globalSettings[prop] = value;
+        try {
+            assert.deepEqual(current,value);
+            return when.resolve();
+        } catch(err) {
+            return storage.saveSettings(globalSettings);
+        }
+    },
+    
+    available: function() {
+        return (globalSettings !== null);
+    },
+    
+    reset: function() {
+        userSettings = null;
+        globalSettings = null;
+        storage = null;
+    }
+}
+
+module.exports = persistentSettings;