gmail.db.js

/* IndexedDB wrapper */

/* 
	From: http://setthebarlow.com/indexeddb/ 
	(with modifications by Anders Sahlin for "Mail Checker Plus for Google Mail™")
*/

var indexedDB = window.indexedDB || window.webkitIndexedDB || window.mozIndexedDB;
 
if ('webkitIndexedDB' in window) {
	window.IDBTransaction = window.webkitIDBTransaction;
	window.IDBKeyRange = window.webkitIDBKeyRange;
}
 
var wrappedDB = {};
wrappedDB.db = null;
wrappedDB.opened = false;
 
wrappedDB.onerror = function(e) {
	console.error(e);
};
 
wrappedDB.open = function(dbName, storeId, callback) {
	var request = indexedDB.open(dbName);
 
	request.onsuccess = function(e) {
		var v = "1.1"; // Structural version of the DB
		wrappedDB.db = e.target.result;
		var db = wrappedDB.db;

		// We can only create Object stores in a setVersion transaction
		if(v!= db.version) {
			var setVrequest = db.setVersion(v);
 
			// onsuccess is the only place we can create Object Stores
			setVrequest.onfailure = wrappedDB.onerror;
			setVrequest.onsuccess = function(e) {
				if(db.objectStoreNames.contains(storeId)) {
					db.deleteObjectStore(storeId);
				}
 
				var store = db.createObjectStore(storeId, {keyPath: "key"}); // Create unique identifier for store
				wrappedDB.opened = true;
				callback();
			};
		}
		else {
			wrappedDB.opened = true;
			callback();
		}
	};
 
	request.onfailure = wrappedDB.onerror;
}
 
wrappedDB.putObject = function(storeId, key, value) {
	if(wrappedDB.opened === false)
		return;

	var db = wrappedDB.db;
	var trans = db.transaction([storeId], IDBTransaction.READ_WRITE, 0);
	
	trans.onabort = function(e) {
		console.error(e);
	};

	var store = trans.objectStore(storeId);
 
	var data = {
		"key": key,
		"value": value
	};
 
	var request = store.put(data);
 
	request.onsuccess = function(e) {
		console.log("Successfully stored object with key: " + key);
	};
	 
	request.onerror = function(e) {
		console.error("An error occured while trying to store an object with key: " + key + ". " 
			+ this.webkitErrorMessage + " (code " + this.errorCode + ")");
	};
};
 
wrappedDB.deleteSetting = function(storeId, key) {
	if(wrappedDB.opened === false)
		return;

	var db = wrappedDB.db;
	var trans = db.transaction([storeId], IDBTransaction.READ_WRITE, 0);
	var store = trans.objectStore(storeId);
 
	var request = store.delete(key);
 
	request.onsuccess = function(e) {
		console.log("Successfully deleted object with key: " + key);
	};
 
	request.onerror = function(e) {
		console.error("An error occured while trying to delete an object with key: " + key + ". " 
			+ this.webkitErrorMessage + " (code " + this.errorCode + ")");
	};
};
 
wrappedDB.readAllObjects = function(storeId, objectFoundCallback, requestCompleteCallback) { 
	if(wrappedDB.opened === false)
		return;

	var db = wrappedDB.db;
	var trans = db.transaction([storeId], IDBTransaction.READ_WRITE, 0);
	var store = trans.objectStore(storeId);
 
	// Get everything in the store;
	var keyRange = IDBKeyRange.lowerBound(0);
	var cursorRequest = store.openCursor(keyRange);
 
	cursorRequest.onsuccess = function(e) {
		var cursor = e.target.result;

		if(!cursor) {
			if(requestCompleteCallback)
				requestCompleteCallback();
		} else { 
			if(objectFoundCallback)
				objectFoundCallback(cursor.value);

			cursor.continue();
		}
	};
 
	cursorRequest.onerror = wrappedDB.onerror;
};

wrappedDB.readObject = function(storeId, key, callback) { 
	if(wrappedDB.opened === false)
		return;

	var db = wrappedDB.db;
	var trans = db.transaction([storeId], IDBTransaction.READ_WRITE, 0);
	var store = trans.objectStore(storeId);
 
	// Get everything in the store;
	var request = store.get(key);
 
	request.onsuccess = function(e) {
		if(callback) {
			if(this.result) {
				callback(this.result.value);
			} else {
				callback(null); // TODO: Better error handling
			}
		}
	};
 
	request.onerror = wrappedDB.onerror;
};