XML and XML HTTP request abstraction.
转自：http://webfx.eae.net/dhtml/xmlextras/xmlextras.html。
xmlextras.js
1 //<script>
2 //////////////////
3 // Helper Stuff //
4 //////////////////
5
6 // used to find the Automation server name
7 function getDomDocumentPrefix() {
8 if (getDomDocumentPrefix.prefix)
9 return getDomDocumentPrefix.prefix;
10
11 var prefixes = ["MSXML2", "Microsoft", "MSXML", "MSXML3"];
12 var o;
13 for (var i = 0; i < prefixes.length; i++) {
14 try {
15 // try to create the objects
16 o = new ActiveXObject(prefixes[i] + ".DomDocument");
17 return getDomDocumentPrefix.prefix = prefixes[i];
18 }
19 catch (ex) {};
20 }
21
22 throw new Error("Could not find an installed XML parser");
23 }
24
25 function getXmlHttpPrefix() {
26 if (getXmlHttpPrefix.prefix)
27 return getXmlHttpPrefix.prefix;
28
29 var prefixes = ["MSXML2", "Microsoft", "MSXML", "MSXML3"];
30 var o;
31 for (var i = 0; i < prefixes.length; i++) {
32 try {
33 // try to create the objects
34 o = new ActiveXObject(prefixes[i] + ".XmlHttp");
35 return getXmlHttpPrefix.prefix = prefixes[i];
36 }
37 catch (ex) {};
38 }
39
40 throw new Error("Could not find an installed XML parser");
41 }
42
43 //////////////////////////
44 // Start the Real stuff //
45 //////////////////////////
46
47
48 // XmlHttp factory
49 function XmlHttp() {}
50
51 XmlHttp.create = function () {
52 try {
53 if (window.XMLHttpRequest) {
54 var req = new XMLHttpRequest();
55
56 // some versions of Moz do not support the readyState property
57 // and the onreadystate event so we patch it!
58 if (req.readyState == null) {
59 req.readyState = 1;
60 req.addEventListener("load", function () {
61 req.readyState = 4;
62 if (typeof req.onreadystatechange == "function")
63 req.onreadystatechange();
64 }, false);
65 }
66
67 return req;
68 }
69 if (window.ActiveXObject) {
70 return new ActiveXObject(getXmlHttpPrefix() + ".XmlHttp");
71 }
72 }
73 catch (ex) {}
74 // fell through
75 throw new Error("Your browser does not support XmlHttp objects");
76 };
77
78 // XmlDocument factory
79 function XmlDocument() {}
80
81 XmlDocument.create = function () {
82 try {
83 // DOM2
84 if (document.implementation && document.implementation.createDocument) {
85 var doc = document.implementation.createDocument("", "", null);
86
87 // some versions of Moz do not support the readyState property
88 // and the onreadystate event so we patch it!
89 if (doc.readyState == null) {
90 doc.readyState = 1;
91 doc.addEventListener("load", function () {
92 doc.readyState = 4;
93 if (typeof doc.onreadystatechange == "function")
94 doc.onreadystatechange();
95 }, false);
96 }
97
98 return doc;
99 }
100 if (window.ActiveXObject)
101 return new ActiveXObject(getDomDocumentPrefix() + ".DomDocument");
102 }
103 catch (ex) {}
104 throw new Error("Your browser does not support XmlDocument objects");
105 };
106
107 // Create the loadXML method and xml getter for Mozilla
108 if (window.DOMParser &&
109 window.XMLSerializer &&
110 window.Node && Node.prototype && Node.prototype.__defineGetter__) {
111
112 // XMLDocument did not extend the Document interface in some versions
113 // of Mozilla. Extend both!
114 //XMLDocument.prototype.loadXML =
115 Document.prototype.loadXML = function (s) {
116
117 // parse the string to a new doc
118 var doc2 = (new DOMParser()).parseFromString(s, "text/xml");
119
120 // remove all initial children
121 while (this.hasChildNodes())
122 this.removeChild(this.lastChild);
123
124 // insert and import nodes
125 for (var i = 0; i < doc2.childNodes.length; i++) {
126 this.appendChild(this.importNode(doc2.childNodes[i], true));
127 }
128 };
129
130
131 /*
132 * xml getter
133 *
134 * This serializes the DOM tree to an XML String
135 *
136 * Usage: var sXml = oNode.xml
137 *
138 */
139 // XMLDocument did not extend the Document interface in some versions
140 // of Mozilla. Extend both!
141 /*
142 XMLDocument.prototype.__defineGetter__("xml", function () {
143 return (new XMLSerializer()).serializeToString(this);
144 });
145 */
146 Document.prototype.__defineGetter__("xml", function () {
147 return (new XMLSerializer()).serializeToString(this);
148 });
149 }
加载 xml 文件
使用异步加载
1 function loadAsync(sUri) {
2 var xmlHttp = XmlHttp.create();
3 var async = true;
4 xmlHttp.open("GET", sUri, async);
5 xmlHttp.onreadystatechange = function () {
6 if (xmlHttp.readyState == 4)
7 doSomething(xmlHttp.responseXML); // responseXML : XmlDocument
8 }
9 xmlHttp.send(null);
10 }
11
12
使用syncronous的 XMLHTTP
1 function loadSync(sUri) {
2 var xmlHttp = XmlHttp.create();
3 var async = false;
4 xmlHttp.open("GET", sUri, async);
5 xmlHttp.send(null);
6 doSomething(xmlHttp.responseXML); // responseXML : XmlDocument
7 }
8
9
发送一个XML 文件
1 function postAsync(sUri, xmlDoc) {
2 var xmlHttp = XmlHttp.create();
3 var async = true;
4 xmlHttp.open("GET", sUri, async);
5 xmlHttp.onreadystatechange = function () {
6 if (xmlHttp.readyState == 4)
7 doSomething(xmlHttp.responseXML); // responseXML : XmlDocument
8 }
9 xmlHttp.send(xmlDoc);
10 }
11
加载一个文本文件
1 function loadTextSync(sUri) {
2 var xmlHttp = XmlHttp.create();
3 var async = false;
4 xmlHttp.open("GET", sUri, async);
5 xmlHttp.send(null);
6 doSomething(xmlHttp.responseText); // responseText : String
7 }
8
使用XmlDocument
1 var doc = XmlDocument.create();
2 doc.loadXML( "<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
3 "<root>" +
4 "<test name=\"Test 1\"/>" +
5 "<test name=\"Test 2\"/>" +
6 "</root>");
7
8 var testEls = doc.getElementsByTagName("test");
9 for (var i = 0; i < testEls.length; i++)
10 alert(tests[i].getAttribute("name"));
11
负载使用 XmlDocument
1 function loadAsync2(sUri) {
2 var doc = XmlDocument.create();
3 doc.async = true;
4 doc.onreadystatechange = function () {
5 if (doc.readyState == 4)
6 alert(doc.xml); // doc.xml : String
7 }
8 doc.load(sUri);
9 }
10
我都有些迷惑，如果可以大家一起讨论一下。