joajax.js

广州物价系统开发部分模块

/*************************************************************************
 * Copyright By Jiny Wu
 *
 * JoAjax.js
 *
 * This is a base class for AJAX
 *
 * var Ajax = new JoAjax(Url, Xml, Callback);
 *
 * Url:         Request url
 * Xml:         Determine whether it uses responseXML or responseText
 * Callback:        User-defined callback function to process result
 * Declaration: void Callback( result )
 *                  If responseXml  then result = XmlDom object
 *                  If responseText then result = HTML text
 *
 * Interface declaration
 * 1) Call( string MethodName, ...): Call server method (POST request)
 *    Call method via JoAjax
 *    Ajax->Call( methodName, param1, param2, ...);
 *
 * 2) Get(): Send GET request
 *    Ajax->Get();
 *
 * 3) Post( array key, array value ): Post form key/value
 *    Ajax->Post( arrKey, arrValue );
 *
 * Utility functions declaration
 * 1) HtmlEntity(string HtmlText): convert html entity
 * 2) StripStags(string HtmlText): remove html tags
 *
 * Author: Jiny Wu
 * Email: [e-mail]
 * Date: 2005/12/02
 * Version: 1.0
 *
 * Notice: ANYONE CAN DUPLICATE THE CLASS FOR STUDY AND ANY NON-BUSINESS PURPOSE,
 *         BUT PLEASE DON'T USE IT AS ANY BUSINESS PURPOSE. IF YOU REALLY WANT TO
 *         DO THAT, PLEASE CONTACT ME AND BE GRANTED. IF THERE IS ANY BUG, PLEASE
 *         REPORT IT TO ME AS SOON AS POSSIBLE. PLEASE DON'T REMOVE THE NOTICE AND
 *         COPYRIGHT AFTER DUPLICATING. ANY OPINION WILL BE WELCOME ALSO.
 *
 * $Id 2005/12/02 8:00:00 $
 *************************************************************************/
/* Error constants definition */
var ERR_OK                              = 0;
var ERR_UNKNOWN_EXCEPTION               = 1;
var ERR_SERVER_SCRIPT                   = 2;
var ERR_XMLHTTPREQUEST_FAILURE          = 3;
var ERR_XML_NOTFORMED                   = 4;
var ERR_CALLBACK_FAIL                   = 5;

/*
 * JoAjax class definition
 * It's a constructor of JoAjax class
 */
function JoAjax( url , xml, callback)
{
    try{
        this.HttpRequest = null;
        this.Debug  = false;
        this.Url = url;
        this.ContentType = "text/xml";
        this.CallbackFunction = callback;
        this.bXml = xml;
        this.Error = ERR_OK;

        this.HttpRequest = this.createXMLHttpRequest();

        if ( this.HttpRequest == null )
        {
            this._debug("XMLHttpRequest create failure!");
            this.Error = ERR_XMLHTTPREQUEST_FAILURE;
            return;
        }

        var xhReq = this.HttpRequest;
        xhReq.onreadystatechange = function (){
            JoAjax._OnReadyStateChange( xhReq, xml, callback );
        }

    } catch(e){
        this.Error = ERR_UNKNOWN_EXCEPTION;
        this._debug( "JoAjax: " + e.message );
    }
}

/*
 * Get URL resource
 */
JoAjax.prototype.Get = function() {

    this.SetContentType( "text/html" );
    this._get();
}

/*
 * Post data to the server
 */
JoAjax.prototype.Post = function( arrKey, arrValue ) {

    var data = '';
    this.SetContentType( "application/x-www-form-urlencoded" );
    for( i = 0; i < arrKey.length; i ++)
    {
        data += "&" + encodeURIComponent(arrKey[i]) + "=" + encodeURIComponent(arrValue[i]);
    }
    data = data.replace(/^&/g, "");
    this._post(data);
}

/*
 * XMLRPC call functions in the server side.
 * Arguments are arbitrary, at least one,which show the name of caller function
 */
JoAjax.prototype.Call = function() {

    var data = '';
    var i = 0;
    this.SetContentType( "text/xml" );

    this._assert( arguments.length >= 1, "There is no specified function name");

    data = "<Request>\n<methodName>"+ arguments[0] +"</methodName>\n";

    for ( i = 1; i < arguments.length; i ++)
    {
        data = data + "<param" + i + ">"+ arguments[i] + "</param"+ i +">\n";
    }
    data = data + "</Request>";
    this._post(data);
}

/*
 * Extract scalar value from xml object
 * <Response>
 * scalarvalue              <=> scalarvalue
 * </Response>
 */
JoAjax.ScalarValue = function ( xmlobj ) {

    if ( xmlobj )
    {
        try
        {
            return xmlobj.getElementsByTagName('Response')[0].firstChild.nodeValue;
        }
        catch (e)
        {
            return null;
        }
    }
    return null;
}

/*
 * Extract array value from xml object
 * <Response>
 * <item>1</item>
 * <item>2</item>      <=>      array(1, 2);
 * </Response>
 */
JoAjax.ArrayValue = function ( xmlobj ) {

    var array = new Array();
    if ( xmlobj )
    {
        try
        {
            var i = 0;
            var response = xmlobj.getElementsByTagName('Response')[0];
            var element = response.firstChild;
            array[i] = element.firstChild.nodeValue;

            while ( element = element.nextSibling )
            {
                i ++;
                array[i] = element.firstChild.nodeValue;
            }
            return array;
        }
        catch (e)
        {
            return array;
        }
    }
    return array;
}

/*
 * Initialization for JoAjax class
 */
JoAjax.prototype.Init = function() {
    // initialization
}

/*
 * Change URL for request
 */
JoAjax.prototype.SetUrl = function( url ) {
    this.Url = url;
}

/*
 * Set content type for HTTP header before sending request
 */
JoAjax.prototype.SetContentType = function( type ) {
    this.ContentType = type;
}

JoAjax.prototype.createXMLHttpRequest = function() {

    try { return new ActiveXObject("Msxml2.XMLHTTP");    } catch(e) {}
    try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) {}
    try { return new XMLHttpRequest();                   } catch(e) {}
    return null;
}

/*
 * Debug information for testing
 */
JoAjax.prototype._debug = function(message) {

    if ( this.Debug )
    {
        alert(message);
    }
}

/*
 * Process message and data from server
 */
JoAjax._OnReadyStateChange = function( xreq, xml, callback ){

    if ( xreq == null )
    {
        return;
    }
    
    /*Status is completed, then process result */
    if ( xreq.readyState == 4)
    {
        // OK
        
        if ( xreq.status == 200 )
        {
            if ( xml )
            {
                var responseXML = xreq.responseXML;
                
                try
                {
                    if ( responseXML.xmlText == "" )
                    {
                        alert('Server Script Error!' + "\n" + JoAjax.StripTags(xreq.responseText) );
                        this.Error = ERR_SERVER_SCRIPT;
                    } else {

                        try
                        {
                            callback ( responseXML );
                        }
                        catch (e)
                        {
                            this.Error = ERR_CALLBACK_FAIL;
                            alert( "Callback " + e.name + " : " + e.message + "\n" + callback);
                        }
                        
                    }
                }
                catch (e)
                {
                    alert('Xml not well-formed : ' + responseXML.xmlText );
                    this.Error = ERR_XML_NOTFORMED;
                    return;
                }
            } else {
                
                try
                {
                    callback ( xreq.responseText );
                }
                catch (e)
                {
                    this.Error = ERR_CALLBACK_FAIL;
                    alert( "Callback " + e.name + " : " + e.message + "\n" + callback);
                }
                
            }
        }
    } else {
        // Others
    }
}

/*
 * Send HTTP request to the server
 * Params:
 *      HttpMethod: HTTP protocol specified method: POST, GET, PUT, HEAD, etc.
 *      data: HTTP entity data. it can be null if the method is GET, PUT and HEAD
 * Return:
 *      true if successfully, or false
 */
JoAjax.prototype._SendRequest = function(HttpMethod, data){

    this._debug( 'Send Request ' + HttpMethod + data );
    this._assert ( this.HttpRequest != null , "XMLHttpRequest should not be NULL");

    if ( this.HttpRequest != null )
    {
        this.HttpRequest.open(HttpMethod, this.Url, true);

        if ( this.ContentType != null )
        {
            //  <FORM> MIME type: application/x-www-form-urlencoded
            this.HttpRequest.setRequestHeader("Content-Type", this.ContentType);
        }
        this.HttpRequest.send(data);
        return true;
    }
    return false;
}

/* Send GET request to server */
JoAjax.prototype._get = function () {

    this._debug( 'GET' );
    return this._SendRequest("GET", null);
}

/* Send POST request and data to server */
JoAjax.prototype._post = function (data) {

    this._debug( 'POST' );
    return this._SendRequest("POST", data);
}

/*
 * ASSERT statement for program robust
 * It"s used to check arguments of functions
 */
JoAjax.prototype._assert = function(condition, errmsg) {

    if ( !condition )
    {
        this._debug("JoAjax ASSERT(): " + errmsg);
    }
}

/*
 * Convert html entity to string
 *
 * Example:
 *
 * "<item>" => "&lt;item&gt;"
 */
JoAjax.HtmlEntity = function ( html ) {

    html = html.replace(/&/g, "&amp;");
    html = html.replace(/</g, '&lt;');
    html = html.replace(/>/g, '&gt;');
    return html;
}

/*
 * Remove HTML tags
 *
 * Example:
 *
 * "<font><b>example</b> hello, world!</font>" => "example hello, world!"
 */
JoAjax.StripTags = function ( html ){
    html = html.replace(/<[^>]+>/g, "");
    return html;
}

function gb2utf8(data){  
    var glbEncode = [];  
    gb2utf8_data = data;  
    execScript("gb2utf8_data = MidB(gb2utf8_data, 1)", "VBScript");  
    var t=escape(gb2utf8_data).replace(/%u/g,"").replace(/(.{2})(.{2})/g,"%$2%$1").replace(/%([A-Z].)%(.{2})/g,"@$1$2");  
    t=t.split("@");  
    var i=0,j=t.length,k;  
    while(++i<j) {  
        k=t[i].substring(0,4);  
        if(!glbEncode[k]) {  
            gb2utf8_char = eval("0x"+k);  
            execScript("gb2utf8_char = Chr(gb2utf8_char)", "VBScript");  
            glbEncode[k]=escape(gb2utf8_char).substring(1,6);  
        }  
        t[i]=glbEncode[k]+t[i].substring(4);  
    }  
    gb2utf8_data = gb2utf8_char = null;  
    return unescape(t.join("%"));  
}