自己动手封装的 ajax

以前开发用了很多ajax的技术比如ext,prototype,jquery等等，但都是开源封装好的ajax框架。从没真正用过纯正的ajax，故参照prototyp面向对象思想自己封装了一个ajax框架。希望能给读者参考、帮助、评价。

/*
* 自己封装的ajax
*
*
* @author 姜松
* @version 1.00 $date:2009-07-02
*
* history:
*
*/
object.extend = function(destination, source) {
for (var property in source) {
destination[property] = source[property];
}
return destination;
};
object.extend(string.prototype, {
include: function(pattern) {
return this.indexof(pattern) > -1;
},
startswith: function(pattern) {
return this.indexof(pattern) == 0;
},
endswith: function(pattern) {
return this.lastindexof(pattern) == (this.length - pattern.length);
},
empty: function() {
return /^\s*$/.test(this) || this == undefined || this == null;
}
});
object.extend(array.prototype, {
each: function(iterator) {
try {
for (var i = 0, length = this.length; i < length; i++) {
iterator(this[i]);
}
} catch (e) {
if (e != 'break') { throw e };
}
},
clear: function() {
this.length = 0;
return this;
},
first: function() {
return this[0];
},
last: function() {
return this[this.length - 1];
},
indexof: function(object) {
for (var i = 0, length = this.length; i < length; i++) {
if (this[i] == object) {return i};
}
return -1;
},
size: function() {
return this.length;
},
include: function(object) {
var found = false;
this.each(function(value) {
if (value == object) {found = true; throw 'break';}
});
return found;
}
});
function $(element) {
if(arguments.length > 1) {
for(var i = 0, elements = [], length = arguments.length; i < length; i++) {
elements.push($(arguments[i]));
}
return elements;
}
if(typeof element == 'string') {
element = document.getelementbyid(element);
}
return element;
};
var ajax = {
transport: new object(),
options: new object(),
gettransport: function() {
if(window.activexobject) {
try {
return new activexobject('msxm12.xmlhttp');
} catch(e) {
try {
return new activexobject('microsoft.xmlhttp');
} catch(e) {}
}
} else if(window.xmlhttprequest) {
try {
return new xmlhttprequest();
} catch(e) {}
}
},
setoptions: function(options) {
ajax.options = {
method: 'get',
asynchronous: true,
contenttype: 'application/x-www-form-urlencoded',
encoding: 'utf-8',
parameters: ''
};
object.extend(ajax.options, options);
ajax.options.method = ajax.options.method.touppercase();
},
request: function(url, options) {
ajax.transport = ajax.gettransport();
ajax.setoptions(options);
this.method = ajax.options.method;
var params = ajax.options.parameters;
if (!['get', 'post'].include(this.method)) {
this.method = 'get';
}
if (this.method == 'get') {
url = ajax.setparameters(url, params);
}
try {
ajax.transport.open(this.method, url, ajax.options.asynchronous);
ajax.transport.onreadystatechange = ajax.statechange;
ajax.setrequestheaders();
this.body = this.method == 'post' ? params : null;
ajax.transport.send(this.body);
} catch (e) {}
},
statechange: function() {
try {
var readystate = ajax.transport.readystate;
if(readystate == 4) {
var status = ajax.transport.status, transport = ajax, json = ajax.evaljson();
if(status == 200) {
ajax.options['onsuccess'](transport, json);
} else {
ajax.options['onfailure'](transport, json);
}
}
} catch (e) {}
},
setparameters: function(url, params) {
if (params && typeof params == 'string') {
url += (url.include('?') ? '&' : '?') + params;
} else if (params && typeof params == 'object') {
for(var param in params) {
url += (url.include('?') ? '&' : '?') + param + '=' + params[param];
}
}
return url;
},
setrequestheaders: function() {
var headers = {
'x-requested-with': 'xmlhttprequest',
'accept': 'application/xml, text/xml, text/html, text/javascript, application/javascript, application/json, text/javascript, text/plain, */*',
'if-modified-since': 'thu, 01 jan 1970 00:00:00 gmt'
};
this.method = ajax.options.method;
if (this.method == 'post') {
headers['content-type'] = ajax.options.contenttype +
(ajax.options.encoding ? '; charset=' + ajax.options.encoding : '');
if (ajax.transport.overridemimetype &&
(navigator.useragent.match(/gecko\/(\d{4})/) || [0,2005])[1] < 2005) {
headers['connection'] = 'close';
}
}
for (var name in headers) {
ajax.transport.setrequestheader(name, headers[name]);
}
},
evaljson: function() {
try {
return eval('(' + ajax.transport.responsetext + ')');
} catch (e) {}
}
};
var form = {
serialize: function(element) {
var elements = $(element).all;
var querycomponents = [];
for(var i = 0; i < elements.length; i++) {
var parameter = null, method = elements[i].tagname.tolowercase();
if(['input', 'select', 'textarea'].include(method)) {
parameter = form.serializers[method](elements[i]);
}
if(parameter != null && parameter.constructor == array) {
var key = encodeuricomponent(parameter[0]);
var value = encodeuricomponent(parameter[1]);
querycomponents.push(key + '=' + value);
}
}
return querycomponents.join('&');
},
request: function(options) {
var params = this.toqueryparams(options.parameters);
options.parameters = this.serialize(this.form);
if(params) {
options.parameters = options.parameters.concat('&' + params);
}
if($(this.form).method) {
options.method = $(this.form).method;
}
return new ajax.request($(this.form).action, options);
},
toqueryparams: function(params) {
var querycomponents = [];
if (params && typeof params == 'string') {
querycomponents.push(encodeuricomponent(params));
} else if (params && typeof params == 'object') {
for(var param in params) {
var key = encodeuricomponent(param);
var value = encodeuricomponent(params[param]);
querycomponents.push(key + '=' + value);
}
}
return querycomponents.join('&');
}
};
form.serializers = {
input: function(element) {
switch(element.type.tolowercase()) {
case 'checkbox':
case 'radio':
return this.inputselector(element);
default:
return this.textarea(element);
}
},
inputselector: function(element) {
if(element.checked) {
return [element.name, element.value];
}
},
textarea: function(element) {
return [element.name, element.value];
},
select: function(element) {
return this[element.type == 'select-one' ?
'selectone' : 'selectmany'](element);
},
selectone: function(element) {
var value = null, option, index = element.selectedindex;
if(index >= 0) {
option = element.options[index];
value = option.value == (undefined || '') ? option.text : option.value;
}
return [element.name, value];
},
selectmany: function(element) {
var value = [];
for(var i = 0; i < element.length; i++) {
var option = element.options[i];
if(option.selected) {
var optvalue = option.value == (undefined || '') ? option.text : option.value;
value.push(optvalue);
}
}
return [element.name, value];
}
};
function $f(element) {
this.form = element;
}
object.extend($f.prototype, form);
/**************************************************************
* 测试函数
*/
function ontest() {
//get提交方法
var params = new object();
params.ss = '张三';
new ajax.request('ajax.do?method=doget', {
onsuccess: function(transport) {
alert(transport.evaljson().xx)
},
parameters: params
});
//post form提交方法
var params = new object();
params.idd = 1000;
params.names = '张三'
new $f('form').request({
onsuccess: function(transport) {
alert(transport.evaljson().xx);
},
parameters: params
});
}