xmlstore.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

		//		'item' must be an instance of a dojox.data.XmlItem from the store instance.
		//		'attribute' can be an XML attribute name of the element or one of
		//		special names described below.
		//		If 'attribute' specifies "tagName", nothing is removed and false is
		//		returned.
		//		If 'attribute' specifies "childNodes" or "text()", all child nodes
		//		are removed.
		//		For generic attributes, if '_attributeMap' is specified,
		//		an actual attribute name is looked up with the tag name of
		//		the element and 'attribute' (concatenated with '.').
		//		Then, if 'attribute' starts with "@", the XML attribute is removed.
		//		Otherwise, child elements of the tag name specified with
		//		'attribute' are removed.
		//	item:
		//		An XML element that holds the attribute
		//	attribute:
		//		A tag name of child elements, an XML attribute name or one of
		//		special names
		//	returns:
		//		False for "tagName", otherwise true
		if(attribute === "tagName"){
			return false; //boolean
		}

		this._backupItem(item);

		var element = item.element;
		if(attribute === "childNodes" || attribute === "text()"){
			while(element.firstChild){
				element.removeChild(element.firstChild);
			}
		}else{
			attribute = this._getAttribute(element.nodeName, attribute);
			if(attribute.charAt(0) === '@'){
				var name = attribute.substring(1);
				element.removeAttribute(name);
			}else{
				for(var i = element.childNodes.length - 1; i >= 0; i--){
					var node = element.childNodes[i];
					if(	node.nodeType === 1 /*ELEMENT_NODE*/ &&
						node.nodeName === attribute){
						element.removeChild(node);
					}
				}
			}
		}
		return true; //boolean
	},
	
	save: function(/* object */ keywordArgs){
		//	summary:
		//		Save new and/or modified items (XML elements)
		// 	description:
		//		'url' is used to save XML documents for new, modified and/or
		//		deleted XML elements.
		// 	keywordArgs:
		//		An object for callbacks
		if(!keywordArgs){
			keywordArgs = {};
		}
		for(var i = 0; i < this._modifiedItems.length; i++){
			this._saveItem(this._modifiedItems[i], keywordArgs, "PUT");
		}
		for(var i = 0; i < this._newItems.length; i++){
			var item = this._newItems[i];
			if(item.element.parentNode){ // reparented
				this._newItems.splice(i, 1);
				i--;
				continue;
			}
			this._saveItem(this._newItems[i], keywordArgs, "POST");
		}
		for(var i = 0; i < this._deletedItems.length; i++){
			this._saveItem(this._deletedItems[i], keywordArgs, "DELETE");
		}
	},

	revert: function(){
		// summary:
		//	Invalidate changes (new and/or modified elements)
		// returns:
		//	True
		console.log("XmlStore.revert() _newItems=" + this._newItems.length);
		console.log("XmlStore.revert() _deletedItems=" + this._deletedItems.length);
		console.log("XmlStore.revert() _modifiedItems=" + this._modifiedItems.length);
		this._newItems = [];
		this._restoreItems(this._deletedItems);
		this._deletedItems = [];
		this._restoreItems(this._modifiedItems);
		this._modifiedItems = [];
		return true; //boolean
	},
	
	isDirty: function(/* item? */ item){
		//	summary:
		//		Check whether an item is new, modified or deleted
		//	description:
		//		If 'item' is specified, true is returned if the item is new,
		//		modified or deleted.
		//		Otherwise, true is returned if there are any new, modified
		//		or deleted items.
		//	item:
		//		An item (XML element) to check
		//	returns:
		//		True if an item or items are new, modified or deleted, otherwise
		//		false
		if (item) {
			var element = this._getRootElement(item.element);
			return (this._getItemIndex(this._newItems, element) >= 0 ||
				this._getItemIndex(this._deletedItems, element) >= 0 ||
				this._getItemIndex(this._modifiedItems, element) >= 0); //boolean
		}
		else {
			return (this._newItems.length > 0 ||
				this._deletedItems.length > 0 ||
				this._modifiedItems.length > 0); //boolean
		}
	},

	_saveItem: function(item, keywordArgs, method){
		if(method === "PUT"){
			url = this._getPutUrl(item);
		}else if(method === "DELETE"){
			url = this._getDeleteUrl(item);
		}else{ // POST
			url = this._getPostUrl(item);
		}
		if(!url){
			if(keywordArgs.onError){
				keywordArgs.onError.call(scope, new Error("No URL for saving content: " + postContent));
			}
			return;
		}

		var saveArgs = {
			url: url,
			method: (method || "POST"),
			contentType: "text/xml",
			handleAs: "xml"
		};
		var saveHander;
		if(method === "PUT"){
			saveArgs.putData = this._getPutContent(item);
			saveHandler = dojo.rawXhrPut(saveArgs);
		}else if(method === "DELETE"){
			saveHandler = dojo.xhrDelete(saveArgs);
		}else{ // POST
			saveArgs.postData = this._getPostContent(item);
			saveHandler = dojo.rawXhrPost(saveArgs);
		}
		var scope = (keywordArgs.scope || dojo.global);
		var self = this;
		saveHandler.addCallback(function(data){
			self._forgetItem(item);
			if(keywordArgs.onComplete){
				keywordArgs.onComplete.call(scope);
			}
		});
		saveHandler.addErrback(function(error){
			if(keywordArgs.onError){
				keywordArgs.onError.call(scope, error);
			}
		});
	},

	_getPostUrl: function(item){
		//	summary:
		//		Generate a URL for post
		//	description:
		//		This default implementation just returns 'url'.
		//		Sub-classes may override this method for the custom URL.
		//	item:
		//		An item to save
		//	returns:
		//		A post URL
		return this.url; //string
	},

	_getPutUrl: function(item){
		//	summary:
		//		Generate a URL for put
		//	description:
		//		This default implementation just returns 'url'.
		//		Sub-classes may override this method for the custom URL.
		//	item:
		//		An item to save
		//	returns:
		//		A put URL
		return this.url; //string
	},

	_getDeleteUrl: function(item){
		//	summary:
		//		Generate a URL for delete
		// 	description:
		//		This default implementation returns 'url' with 'keyAttribute'
		//		as a query string.
		//		Sub-classes may override this method for the custom URL based on
		//		changes (new, deleted, or modified).
		// 	item:
		//		An item to delete
		// 	returns:
		//		A delete URL
		var url = this.url;
		if (item && this.keyAttribute !== "") {
			var value = this.getValue(item, this.keyAttribute);
			if (value) {
				var key = this.keyAttribute.charAt(0) ==='@' ? this.keyAttribute.substring(1): this.keyAttribute;
				url += url.indexOf('?') < 0 ? '?' : '&';
				url += key + '=' + value;
			}
		}
		return url;	//string
	},

	_getPostContent: function(item){
		//	summary:
		//		Generate a content to post
		// 	description:
		//		This default implementation generates an XML document for one
		//		(the first only) new or modified element.
		//		Sub-classes may override this method for the custom post content
		//		generation.
		//	item:
		//		An item to save
		//	returns:
		//		A post content
		var element = item.element;
		var declaration = "<?xml version=\"1.0\"?>"; // FIXME: encoding?
		return declaration + dojox.data.dom.innerXML(element); //XML string
	},

	_getPutContent: function(item){
		//	summary:
		//		Generate a content to put
		// 	description:
		//		This default implementation generates an XML document for one
		//		(the first only) new or modified element.
		//		Sub-classes may override this method for the custom put content
		//		generation.
		//	item:
		//		An item to save
		//	returns:
		//		A post content
		var element = item.element;
		var declaration = "<?xml version=\"1.0\"?>"; // FIXME: encoding?
		return declaration + dojox.data.dom.innerXML(element); //XML string
	},

/* internal API */

	_getAttribute: function(tagName, attribute){
		if(this._attributeMap){
			var key = tagName + "." + attribute;
			var value = this._attributeMap[key];
			if(value){
				attribute = value;
			}else{ // look for global attribute
				value = this._attributeMap[attribute];
				if(value){
					attribute = value;
				}
			}
		}
		return attribute; //object
	},

	_getItem: function(element){
		return new dojox.data.XmlItem(element, this); //object
	},

	_getItemIndex: function(items, element){
		for(var i = 0; i < items.length; i++){
			if(items[i].element === element){
				return i; //int
			}
		}
		return -1; //int
	},

	_backupItem: function(item){
		var element = this._getRootElement(item.element);
		if(	this._getItemIndex(this._newItems, element) >= 0 ||
			this._getItemIndex(this._modifiedItems, element) >= 0){
			return; // new or already modified
		}
		if(element != item.element){
			item = this._getItem(element);
		}
		item._backup = element.cloneNode(true);
		this._modifiedItems.push(item);
	},

	_restoreItems: function(items){

		dojo.forEach(items,function(item){ 
			if(item._backup){
				item.element = item._backup;
				item._backup = null;
			}
		},this); 
	},

	_forgetItem: function(item){
		var element = item.element;
		var index = this._getItemIndex(this._newItems, element);
		if(index >= 0){
			this._newItems.splice(index, 1);
		}
		index = this._getItemIndex(this._deletedItems, element);
		if(index >= 0){
			this._deletedItems.splice(index, 1);
		}
		index = this._getItemIndex(this._modifiedItems, element);
		if(index >= 0){
			this._modifiedItems.splice(index, 1);
		}
	},

	_getDocument: function(element){
		if(element){
			return element.ownerDocument;  //DOMDocument
		}else if(!this._document){
			return dojox.data.dom.createDocument(); // DOMDocument
		}
	},

	_getRootElement: function(element){
		while(element.parentNode){
			element = element.parentNode;
		}
		return element; //DOMElement
	}

});

//FIXME: Is a full class here really needed for containment of the item or would
//an anon object work fine?
dojo.declare("dojox.data.XmlItem", null, {
	constructor: function(element, store) {
		//	summary:
		//		Initialize with an XML element
		//	element:
		//		An XML element
		//	store:
		//		The containing store, if any.
		this.element = element;
		this.store = store;
	}, 
	//	summary:
	//		A data item of 'XmlStore'
	//	description:
	//		This class represents an item of 'XmlStore' holding an XML element.
	//		'element'
	//	element:
	//		An XML element

	toString: function() {
		//	summary:
		//		Return a value of the first text child of the element
		// 	returns:
		//		a value of the first text child of the element
		var str = "";
		if (this.element) {
			for (var i = 0; i < this.element.childNodes.length; i++) {
				var node = this.element.childNodes[i];
				if (node.nodeType === 3) {
					str = node.nodeValue;
					break;
				}
			}
		}
		return str;	//String
	}

});
dojo.extend(dojox.data.XmlStore,dojo.data.util.simpleFetch);

}