_common.js

这是一个ajax的例子大家好好的看看就是一个鱼眼的效果

if(!dojo._hasResource["dojox.off._common"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojox.off._common"] = true;
dojo.provide("dojox.off._common");

dojo.require("dojox.storage");
dojo.require("dojox.sql");
dojo.require("dojox.off.sync");

// Author: Brad Neuberg, [e-mail], http://codinginparadise.org

// summary:
//		dojox.off is the main object for offline applications.
dojo.mixin(dojox.off, {
	// isOnline: boolean
	//	true if we are online, false if not
	isOnline: false,
	
	// NET_CHECK: int
	//		For advanced usage; most developers can ignore this.
	//		Time in seconds on how often we should check the status of the
	//		network with an automatic background timer. The current default
	//		is 5 seconds.
	NET_CHECK: 5,
	
	// STORAGE_NAMESPACE: String
	//		For advanced usage; most developers can ignore this.
	//		The namespace we use to save core data into Dojo Storage.
	STORAGE_NAMESPACE: "_dot",
	
	// enabled: boolean
	//		For advanced usage; most developers can ignore this.
	//		Whether offline ability is enabled or not. Defaults to true.
	enabled: true,
	
	// availabilityURL: String
	//		For advanced usage; most developers can ignore this.
	//		The URL to check for site availability.  We do a GET request on
	//		this URL to check for site availability.  By default we check for a
	//		simple text file in src/off/network_check.txt that has one value
	//		it, the value '1'.
	availabilityURL: dojo.moduleUrl("dojox", "off/network_check.txt"),
	
	// goingOnline: boolean
	//		For advanced usage; most developers can ignore this.
	//		True if we are attempting to go online, false otherwise
	goingOnline: false,
	
	// coreOpFailed: boolean
	//		For advanced usage; most developers can ignore this.
	//		A flag set by the Dojo Offline framework that indicates that the
	//		user denied some operation that required the offline cache or an
	//		operation failed in some critical way that was unrecoverable. For
	//		example, if the offline cache is Google Gears and we try to get a
	//		Gears database, a popup window appears asking the user whether they
	//		will approve or deny this request. If the user denies the request,
	//		and we are doing some operation that is core to Dojo Offline, then
	//		we set this flag to 'true'.  This flag causes a 'fail fast'
	//		condition, turning off offline ability.
	coreOpFailed: false,
	
	// doNetChecking: boolean
	//		For advanced usage; most developers can ignore this.
	//		Whether to have a timing interval in the background doing automatic
	//		network checks at regular intervals; the length of time between
	//		checks is controlled by dojox.off.NET_CHECK. Defaults to true.
	doNetChecking: true,
	
	// hasOfflineCache: boolean
	//		For advanced usage; most developers can ignore this.
	//  	Determines if an offline cache is available or installed; an
	//  	offline cache is a facility that can truely cache offline
	//  	resources, such as JavaScript, HTML, etc. in such a way that they
	//  	won't be removed from the cache inappropriately like a browser
	//  	cache would. If this is false then an offline cache will be
	//  	installed. Only Google Gears is currently supported as an offline
	//  	cache. Future possible offline caches include Firefox 3.
	hasOfflineCache: null,
	
	// browserRestart: boolean
	//		For advanced usage; most developers can ignore this.
	//		If true, the browser must be restarted to register the existence of
	//		a new host added offline (from a call to addHostOffline); if false,
	//		then nothing is needed.
	browserRestart: false,
	
	_STORAGE_APP_NAME: window.location.href.replace(/[^0-9A-Za-z_]/g, "_"),
	
	_initializeCalled: false,
	_storageLoaded: false,
	_pageLoaded: false,
	
	onLoad: function(){
		// summary:
		//	Called when Dojo Offline can be used.
		// description:
		//	Do a dojo.connect to this to know when you can
		//	start using Dojo Offline:
		//		dojo.connect(dojox.off, "onLoad", myFunc);
	},
	
	onNetwork: function(type){
		// summary:
		//	Called when our on- or offline- status changes.
		// description:
		//	If we move online, then this method is called with the
		//	value "online". If we move offline, then this method is
		//	called with the value "offline". You can connect to this
		//	method to do add your own behavior:
		//
		//		dojo.connect(dojox.off, "onNetwork", someFunc)
		//
		//	Note that if you are using the default Dojo Offline UI
		//	widget that most of the on- and off-line notification
		//	and syncing is automatically handled and provided to the
		//	user.
		// type: String
		//	Either "online" or "offline".
	},
	
	initialize: function(){ /* void */
		// summary:
		//		Called when a Dojo Offline-enabled application is finished
		//		configuring Dojo Offline, and is ready for Dojo Offline to
		//		initialize itself.
		// description:
		//		When an application has finished filling out the variables Dojo
		//		Offline needs to work, such as dojox.off.ui.appName, it must
		//		this method to tell Dojo Offline to initialize itself.
		
		//		Note:
		//		This method is needed for a rare edge case. In some conditions,
		//		especially if we are dealing with a compressed Dojo build, the
		//		entire Dojo Offline subsystem might initialize itself and be
		//		running even before the JavaScript for an application has had a
		//		chance to run and configure Dojo Offline, causing Dojo Offline
		//		to have incorrect initialization parameters for a given app,
		//		such as no value for dojox.off.ui.appName. This method is
		//		provided to prevent this scenario, to slightly 'slow down' Dojo
		//		Offline so it can be configured before running off and doing
		//		its thing.	

		//console.debug("dojox.off.initialize");
		this._initializeCalled = true;
		
		if(this._storageLoaded && this._pageLoaded){
			this._onLoad();
		}
	},
	
	goOffline: function(){ /* void */
		// summary:
		//		For advanced usage; most developers can ignore this.
		//		Manually goes offline, away from the network.
		if((dojox.off.sync.isSyncing)||(this.goingOnline)){ return; }
		
		this.goingOnline = false;
		this.isOnline = false;
	},
	
	goOnline: function(callback){ /* void */
		// summary: 
		//		For advanced usage; most developers can ignore this.
		//		Attempts to go online.
		// description:
		//		Attempts to go online, making sure this web application's web
		//		site is available. 'callback' is called asychronously with the
		//		result of whether we were able to go online or not.
		// callback: Function
		//		An optional callback function that will receive one argument:
		//		whether the site is available or not and is boolean. If this
		//		function is not present we call dojo.xoff.onOnline instead if
		//		we are able to go online.
		
		//console.debug("goOnline");
		
		if(dojox.off.sync.isSyncing || dojox.off.goingOnline){
			return;
		}
		
		this.goingOnline = true;
		this.isOnline = false;
		
		// see if can reach our web application's web site
		this._isSiteAvailable(callback);
	},
	
	onFrameworkEvent: function(type /* String */, saveData /* Object? */){
		//	summary:
		//		For advanced usage; most developers can ignore this.
		//		A standard event handler that can be attached to to find out
		//		about low-level framework events. Most developers will not need to
		//		attach to this method; it is meant for low-level information
		//		that can be useful for updating offline user-interfaces in
		//		exceptional circumstances. The default Dojo Offline UI
		//		widget takes care of most of these situations.
		//	type: String
		//		The type of the event:
		//
		//		* "offlineCacheInstalled"
		//			An event that is fired when a user
		//			has installed an offline cache after the page has been loaded.
		//			If a user didn't have an offline cache when the page loaded, a
		//			UI of some kind might have prompted them to download one. This
		//			method is called if they have downloaded and installed an
		//			offline cache so a UI can reinitialize itself to begin using
		//			this offline cache.
		//		* "coreOperationFailed"
		//			Fired when a core operation during interaction with the
		//			offline cache is denied by the user. Some offline caches, such
		//			as Google Gears, prompts the user to approve or deny caching
		//			files, using the database, and more. If the user denies a
		//			request that is core to Dojo Offline's operation, we set
		//			dojox.off.coreOpFailed to true and call this method for
		//			listeners that would like to respond some how to Dojo Offline
		//			'failing fast'.
		//		* "save"
		//			Called whenever the framework saves data into persistent
		//			storage. This could be useful for providing save feedback
		//			or providing appropriate error feedback if saving fails 
		//			due to a user not allowing the save to occur
		//	saveData: Object?
		//		If the type was 'save', then a saveData object is provided with
		//		further save information. This object has the following properties:	
		//
		//		* status - dojox.storage.SUCCESS, dojox.storage.PENDING, dojox.storage.FAILED
		//		Whether the save succeeded, whether it is pending based on a UI
		//		dialog asking the user for permission, or whether it failed. 	
		//
		//		* isCoreSave - boolean
		//		If true, then this save was for a core piece of data necessary
		//		for the functioning of Dojo Offline. If false, then it is a
		//		piece of normal data being saved for offline access. Dojo
		//		Offline will 'fail fast' if some core piece of data could not
		//		be saved, automatically setting dojox.off.coreOpFailed to
		//		'true' and dojox.off.enabled to 'false'.
		//
		// 		* key - String
		//		The key that we are attempting to persist
		//
		// 		* value - Object
		//		The object we are trying to persist
		//
		// 		* namespace - String
		//		The Dojo Storage namespace we are saving this key/value pair
		//		into, such as "default", "Documents", "Contacts", etc.
		//		Optional.
		if(type == "save"){
			if(saveData.isCoreSave && (saveData.status == dojox.storage.FAILED)){
				dojox.off.coreOpFailed = true;
				dojox.off.enabled = false;
			
				// FIXME: Stop the background network thread
				dojox.off.onFrameworkEvent("coreOperationFailed");
			}
		}else if(type == "coreOperationFailed"){
			dojox.off.coreOpFailed = true;
			dojox.off.enabled = false;
			// FIXME: Stop the background network thread
		}
	},
	
	_checkOfflineCacheAvailable: function(callback){
		// is a true, offline cache running on this machine?
		this.hasOfflineCache = dojo.isGears;
		
		callback();
	},
	
	_onLoad: function(){
		//console.debug("dojox.off._onLoad");
		
		// both local storage and the page are finished loading
		
		// cache the Dojo JavaScript -- just use the default dojo.js
		// name for the most common scenario
		// FIXME: TEST: Make sure syncing doesn't break if dojo.js
		// can't be found, or report an error to developer
		dojox.off.files.cache(dojo.moduleUrl("dojo", "dojo.js"));
		
		// pull in the files needed by Dojo