csvstore.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

					}
				}
			}else{
				// We want a copy to pass back in case the parent wishes to sort the array.  We shouldn't allow resort 
				// of the internal list so that multiple callers can get lists and sort without affecting each other.
				if(arrayOfAllItems.length> 0){
					items = arrayOfAllItems.slice(0,arrayOfAllItems.length); 
				}
			}
			findCallback(items, requestArgs);
		};

		if(this._loadFinished){
			filter(keywordArgs, this._arrayOfAllItems);
		}else{
			if(this.url !== ""){
				//If fetches come in before the loading has finished, but while
				//a load is in progress, we have to defer the fetching to be 
				//invoked in the callback.
				if(this._loadInProgress){
					this._queuedFetches.push({args: keywordArgs, filter: filter});
				}else{
					this._loadInProgress = true;
					var getArgs = {
							url: self.url, 
							handleAs: "text"
						};
					var getHandler = dojo.xhrGet(getArgs);
					getHandler.addCallback(function(data){
						self._processData(data);
						filter(keywordArgs, self._arrayOfAllItems);
						self._handleQueuedFetches();
					});
					getHandler.addErrback(function(error){
						self._loadInProgress = false;
						if(errorCallback){
							errorCallback(error, keywordArgs);
						}else{
							throw error;
						}
					});
				}
			}else if(this._csvData){
				this._processData(this._csvData);
				this._csvData = null;
				filter(keywordArgs, this._arrayOfAllItems);
			}else{
				var error = new Error("dojox.data.CsvStore: No CSV source data was provided as either URL or String data input.");
				if(errorCallback){
					errorCallback(error, keywordArgs);
				}else{
					throw error;
				}
			}
		}
	},
	
	close: function(/*dojo.data.api.Request || keywordArgs || null */ request){
		 //	summary: 
		 //		See dojo.data.api.Read.close()
	},
	
	
	// -------------------------------------------------------------------
	// Private methods
	_getArrayOfArraysFromCsvFileContents: function(/* string */ csvFileContents){
		/* summary:
		 *   Parses a string of CSV records into a nested array structure.
		 * description:
		 *   Given a string containing CSV records, this method parses
		 *   the string and returns a data structure containing the parsed
		 *   content.  The data structure we return is an array of length
		 *   R, where R is the number of rows (lines) in the CSV data.  The 
		 *   return array contains one sub-array for each CSV line, and each 
		 *   sub-array contains C string values, where C is the number of 
		 *   columns in the CSV data.
		 */
		 
		/* example:
		 *   For example, given this CSV string as input:
		 *     "Title, Year, Producer \n Alien, 1979, Ridley Scott \n Blade Runner, 1982, Ridley Scott"
		 *   this._dataArray will be set to:
		 *     [["Alien", "1979", "Ridley Scott"],
		 *      ["Blade Runner", "1982", "Ridley Scott"]]
		 *   And this._attributes will be set to:
		 *     ["Title", "Year", "Producer"]
		 *   And this._attributeIndexes will be set to:
		 *     { "Title":0, "Year":1, "Producer":2 }
		 */
		if(dojo.isString(csvFileContents)){
			var lineEndingCharacters = new RegExp("\r\n|\n|\r");
			var leadingWhiteSpaceCharacters = new RegExp("^\\s+",'g');
			var trailingWhiteSpaceCharacters = new RegExp("\\s+$",'g');
			var doubleQuotes = new RegExp('""','g');
			var arrayOfOutputRecords = [];
			
			var arrayOfInputLines = csvFileContents.split(lineEndingCharacters);
			for(var i = 0; i < arrayOfInputLines.length; ++i){
				var singleLine = arrayOfInputLines[i];
				if(singleLine.length > 0){
					var listOfFields = singleLine.split(',');
					var j = 0;
					while(j < listOfFields.length){
						var space_field_space = listOfFields[j];
						var field_space = space_field_space.replace(leadingWhiteSpaceCharacters, ''); // trim leading whitespace
						var field = field_space.replace(trailingWhiteSpaceCharacters, ''); // trim trailing whitespace
						var firstChar = field.charAt(0);
						var lastChar = field.charAt(field.length - 1);
						var secondToLastChar = field.charAt(field.length - 2);
						var thirdToLastChar = field.charAt(field.length - 3);
						if(field.length === 2 && field == "\"\""){
							listOfFields[j] = "";  //Special case empty string field.
						}else if((firstChar == '"') && 
								((lastChar != '"') || 
								 ((lastChar == '"') && (secondToLastChar == '"') && (thirdToLastChar != '"')))){
							if(j+1 === listOfFields.length){
								// alert("The last field in record " + i + " is corrupted:\n" + field);
								return null; //null
							}
							var nextField = listOfFields[j+1];
							listOfFields[j] = field_space + ',' + nextField;
							listOfFields.splice(j+1, 1); // delete element [j+1] from the list
						}else{
							if((firstChar == '"') && (lastChar == '"')){
								field = field.slice(1, (field.length - 1)); // trim the " characters off the ends
								field = field.replace(doubleQuotes, '"');   // replace "" with "
							}
							listOfFields[j] = field;
							j += 1;
						}
					}
					arrayOfOutputRecords.push(listOfFields);
				}
			}
			
			// The first item of the array must be the header row with attribute names.
			this._attributes = arrayOfOutputRecords.shift();
			for(var i=0; i<this._attributes.length; i++){
				// Store the index of each attribute 
				this._attributeIndexes[this._attributes[i]] = i;
			}
			this._dataArray = arrayOfOutputRecords; //Array
		}
	},
	
	_processData: function(/* String */ data){
		this._getArrayOfArraysFromCsvFileContents(data);
		this._arrayOfAllItems = [];
		for(var i=0; i<this._dataArray.length; i++){
			this._arrayOfAllItems.push(this._createItemFromIdentity(i));
		}
		this._loadFinished = true;
		this._loadInProgress = false;
	},
	
	_createItemFromIdentity: function(/* String */ identity){
		var item = {};
		item[this._storeProp] = this;
		item[this._idProp] = identity;
		return item; //Object
	},
	
	
/***************************************
     dojo.data.api.Identity API
***************************************/
	getIdentity: function(/* item */ item){
		//	summary: 
		//		See dojo.data.api.Identity.getIdentity()
		if(this.isItem(item)){
			return item[this._idProp]; //String
		}
		return null; //null
	},

	fetchItemByIdentity: function(/* Object */ keywordArgs){
		//	summary: 
		//		See dojo.data.api.Identity.fetchItemByIdentity()

		//Hasn't loaded yet, we have to trigger the load.
		

		if(!this._loadFinished){
			var self = this;
			if(this.url !== ""){
				//If fetches come in before the loading has finished, but while
				//a load is in progress, we have to defer the fetching to be 
				//invoked in the callback.
				if(this._loadInProgress){
					this._queuedFetches.push({args: keywordArgs});
				}else{
					this._loadInProgress = true;
					var getArgs = {
							url: self.url, 
							handleAs: "text"
						};
					var getHandler = dojo.xhrGet(getArgs);
					getHandler.addCallback(function(data){
						var scope =  keywordArgs.scope?keywordArgs.scope:dojo.global;
						try{
							self._processData(data);
							var item = self._createItemFromIdentity(keywordArgs.identity);
							if(!self.isItem(item)){
								item = null;
							}
							if(keywordArgs.onItem){
								keywordArgs.onItem.call(scope, item);
							}
							self._handleQueuedFetches();
						}catch(error){
							if(keywordArgs.onError){
								keywordArgs.onError.call(scope, error);
							}
						}
					});
					getHandler.addErrback(function(error){
						this._loadInProgress = false;
						if(keywordArgs.onError){
							var scope =  keywordArgs.scope?keywordArgs.scope:dojo.global;
							keywordArgs.onError.call(scope, error);
						}
					});
				}
			}else if(this._csvData){
				self._processData(self._csvData);
				self._csvData = null;
				var item = self._createItemFromIdentity(keywordArgs.identity);
				if(!self.isItem(item)){
					item = null;
				}
				if(keywordArgs.onItem){
					var scope =  keywordArgs.scope?keywordArgs.scope:dojo.global;
					keywordArgs.onItem.call(scope, item);
				}
			}
		}else{
			//Already loaded.  We can just look it up and call back.
			var item = this._createItemFromIdentity(keywordArgs.identity);
			if(!this.isItem(item)){
				item = null;
			}
			if(keywordArgs.onItem){
				var scope =  keywordArgs.scope?keywordArgs.scope:dojo.global;
				keywordArgs.onItem.call(scope, item);
			}
		}
	},

	getIdentityAttributes: function(/* item */ item){
		 //	summary: 
		 //		See dojo.data.api.Identity.getIdentifierAttributes()
		 
		 //Identity isn't a public attribute in the item, it's the row position index.
		 //So, return null.
		 return null;
	},

	_handleQueuedFetches: function(){
		//	summary: 
		//		Internal function to execute delayed request in the store.
		//Execute any deferred fetches now.
		if (this._queuedFetches.length > 0) {
			for(var i = 0; i < this._queuedFetches.length; i++){
				var fData = this._queuedFetches[i];
				var delayedFilter = fData.filter;
				var delayedQuery = fData.args;
				if(delayedFilter){
					delayedFilter(delayedQuery, this._arrayOfAllItems); 
				}else{
					this.fetchItemByIdentity(fData.args);
				}
			}
			this._queuedFetches = [];
		}
	}
});
//Mix in the simple fetch implementation to this class.
dojo.extend(dojox.data.CsvStore,dojo.data.util.simpleFetch);

}