Va gör egentligen detta kodstycke?
Vad kan dra för nytta utav koden, vore kul att se användningsområdet, då det är ganska mycket kod, och jag begriper inget utav koden. :)
//
// jsrsClient.js - javascript remote scripting client include
//
// Author: Brent Ashley [jsrs@megahuge.com]
//
// make asynchronous remote calls to server without client page refresh
//
// see license.txt for copyright and license information
/*
see history.txt for full history
2.0 26 Jul 2001 - added POST capability for IE/MOZ
*/
// callback pool needs global scope
var jsrsContextPoolSize = 0;
var jsrsContextMaxPool = 10;
var jsrsContextPool = new Array();
var jsrsBrowser = jsrsBrowserSniff();
var jsrsPOST = true;
// constructor for context object
function jsrsContextObj( contextID ){
// properties
this.id = contextID;
this.busy = true;
this.callback = null;
this.container = contextCreateContainer( contextID );
// methods
this.GET = contextGET;
this.POST = contextPOST;
this.getPayload = contextGetPayload;
this.setVisibility = contextSetVisibility;
}
// method functions are not privately scoped
// because Netscape's debugger chokes on private functions
function contextCreateContainer( containerName ){
// creates hidden container to receive server data
var container;
switch( jsrsBrowser ) {
case 'NS':
container = new Layer(100);
container.name = containerName;
container.visibility = 'hidden';
container.clip.width = 100;
container.clip.height = 100;
break;
case 'IE':
document.body.insertAdjacentHTML( "afterBegin", '<span id="SPAN' + containerName + '"></span>' );
var span = document.all( "SPAN" + containerName );
var html = '<iframe name="' + containerName + '" src=""></iframe>';
span.innerHTML = html;
span.style.display = 'none';
container = window.frames[ containerName ];
break;
case 'MOZ':
var span = document.createElement('SPAN');
span.id = "SPAN" + containerName;
document.body.appendChild( span );
var iframe = document.createElement('IFRAME');
iframe.name = containerName;
span.appendChild( iframe );
container = iframe;
break;
}
return container;
}
function contextPOST( rsPage, func, parms ){
var d = new Date();
var unique = d.getTime() + '' + Math.floor(1000 * Math.random());
var doc = (jsrsBrowser == "IE" ) ? this.container.document : this.container.contentDocument;
doc.open();
doc.write('<html><body>');
doc.write('<form name="jsrsForm" method="post" target="" ');
doc.write(' action="' + rsPage + '?U=' + unique + '">');
doc.write('<input type="hidden" name="C" value="' + this.id + '">');
// func and parms are optional
if (func != null){
doc.write('<input type="hidden" name="F" value="' + func + '">');
if (parms != null){
if (typeof(parms) == "string"){
// single parameter
doc.write( '<input type="hidden" name="P0" '
+ 'value="[' + jsrsEscapeQQ(parms) + ']">');
} else {
// assume parms is array of strings
for( var i=0; i < parms.length; i++ ){
doc.write( '<input type="hidden" name="P' + i + '" '
+ 'value="[' + jsrsEscapeQQ(parms[i]) + ']">');
}
} // parm type
} // parms
} // func
doc.write('</form></body></html>');
doc.close();
doc.forms['jsrsForm'].submit();
}
function contextGET( rsPage, func, parms ){
// build URL to call
var URL = rsPage;
// always send context
URL += "?C=" + this.id;
// func and parms are optional
if (func != null){
URL += "&F=" + escape(func);
if (parms != null){
if (typeof(parms) == "string"){
// single parameter
URL += "&P0=[" + escape(parms+'') + "]";
} else {
// assume parms is array of strings
for( var i=0; i < parms.length; i++ ){
URL += "&P" + i + "=[" + escape(parms[i]+'') + "]";
}
} // parm type
} // parms
} // func
// unique string to defeat cache
var d = new Date();
URL += "&U=" + d.getTime();
// make the call
switch( jsrsBrowser ) {
case 'NS':
this.container.src = URL;
break;
case 'IE':
this.container.document.location.replace(URL);
break;
case 'MOZ':
this.container.src = '';
this.container.src = URL;
break;
}
}
function contextGetPayload(){
switch( jsrsBrowser ) {
case 'NS':
return this.container.document.forms['jsrs_Form'].elements['jsrs_Payload'].value;
case 'IE':
return this.container.document.forms['jsrs_Form']['jsrs_Payload'].value;
case 'MOZ':
return window.frames[this.container.name].document.forms['jsrs_Form']['jsrs_Payload'].value;
}
}
function contextSetVisibility( vis ){
switch( jsrsBrowser ) {
case 'NS':
this.container.visibility = (vis)? 'show' : 'hidden';
break;
case 'IE':
document.all("SPAN" + this.id ).style.display = (vis)? '' : 'none';
break;
case 'MOZ':
document.getElementById("SPAN" + this.id).style.visibility = (vis)? '' : 'hidden';
this.container.width = (vis)? 250 : 0;
this.container.height = (vis)? 100 : 0;
break;
}
}
// end of context constructor
function jsrsGetContextID(){
var contextObj;
for (var i = 1; i <= jsrsContextPoolSize; i++){
contextObj = jsrsContextPool[ 'jsrs' + i ];
if ( !contextObj.busy ){
contextObj.busy = true;
return contextObj.id;
}
}
// if we got here, there are no existing free contexts
if ( jsrsContextPoolSize <= jsrsContextMaxPool ){
// create new context
var contextID = "jsrs" + (jsrsContextPoolSize + 1);
jsrsContextPool[ contextID ] = new jsrsContextObj( contextID );
jsrsContextPoolSize++;
return contextID;
} else {
alert( "jsrs Error: context pool full" );
return null;
}
}
function jsrsExecute( rspage, callback, func, parms, visibility ){
// call a server routine from client code
//
// rspage - href to asp file
// callback - function to call on return
// or null if no return needed
// (passes returned string to callback)
// func - sub or function name to call
// parm - string parameter to function
// or array of string parameters if more than one
// visibility - optional boolean to make container visible for debugging
// get context
var contextObj = jsrsContextPool[ jsrsGetContextID() ];
contextObj.callback = callback;
var vis = (visibility == null)? false : visibility;
contextObj.setVisibility( vis );
if ( jsrsPOST && ((jsrsBrowser == 'IE') || (jsrsBrowser == 'MOZ'))){
contextObj.POST( rspage, func, parms );
} else {
contextObj.GET( rspage, func, parms );
}
return contextObj.id;
}
function jsrsLoaded( contextID ){
// get context object and invoke callback
var contextObj = jsrsContextPool[ contextID ];
if( contextObj.callback != null){
contextObj.callback( jsrsUnescape( contextObj.getPayload() ), contextID );
}
// clean up and return context to pool
contextObj.callback = null;
contextObj.busy = false;
}
function jsrsError( contextID, str ){
alert( unescape(str) );
jsrsContextPool[ contextID ].busy = false
}
function jsrsEscapeQQ( thing ){
return thing.replace(/'"'/g, '\\"');
}
function jsrsUnescape( str ){
// payload has slashes escaped with whacks
return str.replace( /\\\//g, "/" );
}
function jsrsBrowserSniff(){
if (document.layers) return "NS";
if (document.all) return "IE";
if (document.getElementById) return "MOZ";
return "OTHER";
}
/////////////////////////////////////////////////
//
// user functions
function jsrsArrayFromString( s, delim ){
// rebuild an array returned from server as string
// optional delimiter defaults to ~
var d = (delim == null)? '~' : delim;
return s.split(d);
}
function jsrsDebugInfo(){
// use for debugging by attaching to f1 (works with IE)
// with onHelp = "return jsrsDebugInfo();" in the body tag
var doc = window.open().document;
doc.open;
doc.write( 'Pool Size: ' + jsrsContextPoolSize + '<br><font face="arial" size="2"><b>' );
for( var i in jsrsContextPool ){
var contextObj = jsrsContextPool[i];
doc.write( '<hr>' + contextObj.id + ' : ' + (contextObj.busy ? 'busy' : 'available') + '<br>');
doc.write( contextObj.container.document.location.pathname + '<br>');
doc.write( contextObj.container.document.location.search + '<br>');
doc.write( '<table border="1"><tr><td>' + contextObj.container.document.body.innerHTML + '</td></tr></table>' );
}
doc.write('</table>');
doc.close();
return false;
}