ajax详解_动力节点Java学院整理

!doctype html>
html lang="en"> 
head>
 meta charset="utf-8">
 title>Simple Ajax Example/title>
 meta name="author" content="Rob Larsen">
 meta name="viewport" content="width=device-width, initial-scale=1.0">
 link rel="stylesheet" href="_assets/css/style.css" rel="external nofollow" >
/head>
body>
 div id="main">
  h1>Simple Ajax Example/h1>
  p>strong id="activate">Click here/strong> 
   and content will be appended after this paragraph/p>
 /div>
 script src="_assets/js/ajax.js">/script>
/body>
/html>

/*
Here's a basic Ajax function
*/
var ajax = function( opts ) {
/*
We have an options argument. 
In addition, we want to have some smart defaults.
*/
 opts = {
  //Is it a Get or Post
  type: opts.type || "POST",
  //What URL are we going to hit?
  url: opts.url || "",
  //What do we do with the data
  onSuccess: opts.onSuccess || function(){},
  //what kind of data do we expect?
  data: opts.data || "xml"
 };
//create a new XMLHttpRequest 
 var xhr = new XMLHttpRequest();
//Open the connection to the server 
 xhr.open(opts.type, opts.url, true);
/*
When the ready state changes
fire this function
*/
 xhr.onreadystatechange = function(){
 //readyState 4 is "done" 
 if ( xhr.readyState == 4 ) {
 /*
 do some simple data processing
 There are two components to the returned object-
 responseXML and responseText. 
 Depending on what we're doing we'll need one or the other.
 */
 switch (opts.data){
  case "json":
   //json is text
   opts.onSuccess(xhr.responseText);
   break;
  case "xml":
   //XML retains the structure/DOM 
   //It's passed in whole. 
   opts.onSuccess(xhr.responseXML);
   break;
  default : 
   //Everything else will get TXT
   opts.onSuccess(xhr.responseText);;
  }   
 }
 };
 //close the connection
 xhr.send(null);
}
//here's our simple function
var ajaxSample = function(e){
//Simple callback adds some text to the page 
 var callback = function( data ) {
 document.getElementById("main").innerHTML += 
  "p>"
  +data.getElementsByTagName("data")[0].getAttribute("value")
  +"/p>";
}
//And here's our Ajax call 
 ajax({
  type: "GET",
  url: "_assets/data/ajax-1.xml",
  onSuccess: callback,
  data : "xml"
 })
//prevent the default action 
 e.preventDefault();
}
//Wire everything up
document.getElementById("activate").addEventListener("click", ajaxSample, false);

var ajax = function( opts ) {
 opts = {
 type: opts.type || "POST",
 url: opts.url || "",
 onSuccess: opts.onSuccess || function(){},
 data: opts.data || "xml"
 };
/*
Support for the original ActiveX object in older versions of Internet Explorer
This works all the way back to IE5.
*/
 if ( typeof XMLHttpRequest == "undefined" ) {
 XMLHttpRequest = function () {
  try { 
   return new ActiveXObject("Msxml2.XMLHTTP.6.0"); 
  }
  catch (e) {}
  try { 
   return new ActiveXObject("Msxml2.XMLHTTP.3.0"); 
  }
  catch (e) {}
  try { 
   return new ActiveXObject("Msxml2.XMLHTTP"); 
  }
  catch (e) {}
  throw new Error("No XMLHttpRequest.");
 };
 }
 var xhr = new XMLHttpRequest();
 xhr.open(opts.type, opts.url, true);
 xhr.onreadystatechange = function(){
 if ( xhr.readyState == 4 ) {
  switch (opts.data){
  case "json":
   opts.onSuccess(xhr.responseText);
   break;
  case "xml":
   opts.onSuccess(xhr.responseXML);
   break;
  default : 
   opts.onSuccess(xhr.responseText);;
  }   
 }
 };
 xhr.send(null);
}
var ajaxSample = function(e){
 var callback = function( data ) {
 document.getElementById("main").innerHTML += "p>"
  +data.getElementsByTagName("data")[0].getAttribute("value")
  +"/p>";
 }
 ajax({
 type: "GET",
 url: "_assets/data/ajax-1.xml",
 onSuccess: callback,
 data: "xml"
 })
 e.preventDefault();
}
document.getElementById("activate").addEventListener("click", ajaxSample, false);

var ajax = function( opts ) {
 opts = {
 type: opts.type || "POST",
 url: opts.url || "",
 onSuccess: opts.onSuccess || function(){},
 data: opts.data || "xml"
 };
 var xhr = new XMLHttpRequest();
 xhr.open(opts.type, opts.url, true);
 xhr.onreadystatechange = function(){
 if ( xhr.readyState == 4 ) {
  switch (opt.sdata){
  case "json":
   opt.onSuccess(xhr.responseText);
   break;
  case "xml":
   opt.onSuccess(xhr.responseXML);
   break;
  default : 
   opt.onSuccess(xhr.responseText);;
  }   
 }
 };
 xhr.send(null);
}
var jsonSample = function(e){
 var callback = function( data ) {
 //here, the data is actually a string
 //we use JSON.parse to turn it into an object
 data = JSON.parse(data);
 /*
 we can then use regular JavaScript object references
 to get at our data. 
 */
 document.getElementById("main").innerHTML += "p>"
  + data.sample.txt 
  +"/p>";
 }
 ajax({
 type: "GET",
 url: "_assets/data/json-1.json",
 onSuccess: callback,
 data : "json"
 })
 e.preventDefault();
}
document.getElementById("activate").addEventListener("click", jsonSample, false);

var callback = function( data ) {
 document.getElementById("main").innerHTML += "p>"+ data.sample.txt +"/p>";
}
var jsonpSample = function(e){
//create a script element
 var jsonp = document.createElement("script");
//give it a source with the callback name appended in the query string
 jsonp.src= "_assets/data/jsonp.do?callback=callback";
//add it to the doc
 document.body.appendChild(jsonp);
 e.preventDefault();
}
//wire up the event
document.getElementById("activate").addEventListener("click", jsonpSample, false);

/*
callback is a simple function that will be run
when the data is returned from the server
*/
var callback = function( data ) {
/* 
it just adds a little bit of text to the document
data is the JSON object returned by the server. 
*/
 $("#main").append($("p />").text(data.sample.txt));
}
/*
Wire up the ajax call to this click event
*/
$("#activate").click(
 function(){
//call $.ajax with a configuration object 
 $.ajax({
//it's just a get request
  type: 'get',
//we're looking for this URL 
  url: '_assets/data/json-1.json',
//Our cool callback function
  success: callback,
//it's going to be JSON 
  dataType: "json"
 })
 } 
)

/*
this is the object we're going to post
*/
var myMessages = {
 positive : "Today is a good day",
 negative : "Today stinks",
 meh : "meh"
}
var callback = function( data ) {
 $("#main").append($("p />").text(data.positive));
}
/*
Setting up a simple error handler.
It doesn't do much. 
It's just nice to illustrate error handling.
*/
var errorHandler = function( xhr, textStatus, errorThrown ){
 throw new Error("There was an error. The error status was " + textStatus );
}
/*
Here's where the action happens.
Attach an event to out simple button.
*/
$("#activate").click(
 function(){
//call $.ajax with a configuration object 
  $.ajax({
   //we're sending data to the server  
   type: 'POST',
   //this is our URL
   url: '_assets/data/post-responder.do',
   /*
   This is our data, JSON stringified
   jQuery expects to use native JSON
   or JSON2.js in unsupported browsers
   */
   data: JSON.stringify(myMessages),
   //Here's where we set up our callback function
   success: callback,
   //The data expected from the server
   dataType: "json",
   //And our simple error handler
   error : errorHandler
   }
  )
 }
);

var callback = function( data ) {
//note the document.getelementById alias
 dojo.byId("main").innerHTML += "p>"+ data.sample.txt +"/p>";
}
var getData = function(){
//xhrGet is for get requests
dojo.xhrGet({
 //the URL of the request
 url: "_assets/data/json-1.json",
 //Handle the result as JSON data
 handleAs: "json",
 //The success handler
 load: callback
});
}
// Use connect to attach events
dojo.connect( dojo.byId("activate"), "onclick", getData );

var myMessages = {
 positive : "Today is a good day",
 negative : "Today stinks",
 meh : "meh"
}
var callback = function( data ) {
 dojo.byId("main").innerHTML += "p>"+ data.positive +"/p>";
}
var errorHandler = function(){
 throw new Error("We dun goofed.")
}
var postData = function(){
 //not surprisingly xhrPost is for POST
 dojo.xhrPost({
  // The URL of the request
  url: "_assets/data/post-responder.do",
  //This will be JSON
  handleAs: "json",
  //Set the headers properly
  headers: { "Content-Type": "application/json; charset=uft-8"},
  //Use Dojo's JSON utility
  postData: dojo.toJson(myMessages),
  // The success handler
  load: callback,
  // The error handler
  error: errorHandler
 });
}
// Use connect to attach events
dojo.connect( dojo.byId("activate"), "onclick", postData );

// Create a new YUI instance and populate it with the required modules.
YUI().use('node','event', 'json', 'io', function (Y) {
 var callback = function( id, xhr ) {
  var data = Y.JSON.parse(xhr.responseText);
  Y.one('#main').append("p>" 
   + data.sample.txt 
   +"/p>");
 }
 Y.one("#activate").on('click',
  function(){
   Y.io( '_assets/data/json-1.json', {
   //This is actually the default
   method: 'get',
   on:  {success: callback}
   })
  } 
 )
});

YUI().use('node','event', 'json', 'io', function (Y) {
 var myMessages = {
  positive : "Today is a good day",
  negative : "Today stinks",
  meh : "meh"
 } 
 var callback = function( id, xhr ) {
  var data = Y.JSON.parse(xhr.responseText);
  Y.one('#main').append("p>" 
   + data.positive 
   +"/p>");
 }
 var errorHandler = function( id, xhr){
  throw new Error("There was an error. The error status was " 
   + xhr.statusText 
   +".")
 }
 Y.one("#activate").on('click',
  function(){
   Y.io( '_assets/data/post-responder.do', {
   method: 'post',
   //Use the Y.JSON utility to convert messages to a string
   data : Y.JSON.stringify(myMessages),
   //All response methods are encapsulated in
   //the on object
   on:  {success: callback,
   failure: errorHandler }
   })
  } 
 )
});