Wufoo iframe javascript coolness

function WufooForm(){
this.host='wufoo.com',
this.userName='',
this.formHash='',
this.ssl='unset',
this.autoResize=true,
this.height='',
this.width='100%',
this.disabled=false,
this.frameUrl='',
this.defaultValues='',
this.key='',
this.polling=false,
this.resizeDone='',
this.initialize=function(params){
for(key in params){
this[key]=params[key];
}
this.key=this.formHash+''+Math.floor(Math.random()*1000000);
this.generateFrameUrl();
this.addEvent(window,'message',this.bindMethod(this.resizeWufooForm,this));
},
this.generateFrameUrl=function(){
var url='';
var refer = document.referrer;
refer = refer.replace(/\//g, "wuslash");
refer = refer.replace(/\+/g, "wube");
url+=this.determineSecurity();
url+=this.userName+'.'+this.host+'/embed/'+this.formHash+'/';
url+='def/embedKey='+this.key;
url += '&referrer='+encodeURIComponent(refer);
if(this.defaultValues!='')url+='&'+this.defaultValues;
if(this.ssl==false)url+='&secure=false';
if(this.disabled)url+='&disable=true';
if(this.autoResize==false)url+='&scrolling=true';
this.frameUrl=url;
},
this.generateFullPageUrl=function(){
var url='';
url+=this.determineSecurity();
url+=this.userName+'.'+this.host+'/forms/'+this.formHash+'/';
if(this.ssl==false)url+='http/true/';
return url;
}
this.addResizeScript=function(){
if(!this.polling){
var self=this;
setTimeout(function(){
var script=document.createElement("script");
script.setAttribute("src",document.location.protocol+"//"+self.host+"/forms/height.js?embedKey="+self.key+"&variable="+self.formHash+"&timestamp="+new Date().getTime().toString());
script.setAttribute("type","text/javascript");
document.body.appendChild(script);
},50);
}
},
this.resizeForm=function(ret){
if(this.autoResize==true&&ret.height){
document.getElementById('wufooForm'+this.formHash).height=ret.height;
if(ret.rules=='1'||this.isFunction(this.resizeDone)){
if(this.isFunction(this.resizeDone))this.resizeDone(ret.height);
__wufooCallBackFn=this.resizeDone;
this.appendChildProxyFrame(ret.protocol);
__poll(this.formHash);
this.polling=true;
}
}
},
this.isFunction=function(object){
return typeof object==="function";
},
this.determineSecurity=function(){
if(this.ssl==true)return'https://';
else return'http://';
},
this.generateFrameMarkup=function(){
var scroll='no';
if(this.autoResize==false)scroll='auto';
var src='<iframe id="wufooForm'+this.formHash+'" height="'+this.height+'" allowTransparency="true" frameborder="0" scrolling="'+scroll+'" style="width:'+this.width+';border:none"'+
'src="'+this.frameUrl+'"><a href="'+this.generateFullPageUrl()+'" title="html form" rel="nofollow">Fill out my Wufoo form!</a></iframe>';
return src;
},
this.display=function(){
document.write(this.generateFrameMarkup());
if(!window.postMessage)this.addEvent(document.getElementById('wufooForm'+this.formHash),'load',this.bindMethod(this.addResizeScript,this));
},
this.resizeWufooForm=function(event){
if(event.origin!='http://'+this.userName+'.'+this.host&&
event.origin!='https://'+this.userName+'.'+this.host){
return;
}
if(this.autoResize==true){
var data=event.data.split('|');
var newFormHeight=new Number(data[0]);
var formEl=document.getElementById('wufooForm'+this.formHash);
if(formEl&&this.isMessageFromCorrectForm(data[1])){
formEl.height=newFormHeight;
}
if(this.isFunction(this.resizeDone)){
this.resizeDone(newFormHeight);
}
}
},
this.isMessageFromCorrectForm=function(dataHash){
var hash=dataHash.substring(0,this.formHash.length);
return(hash==this.formHash)?true:false;
},
this.addEvent=function(obj,type,fn){
if(obj.attachEvent){
obj["e"+type+fn]=fn;
obj[type+fn]=function(){obj["e"+type+fn](window.event)};
obj.attachEvent("on"+type,obj[type+fn]);
}
else{
obj.addEventListener(type,fn,false);
}
},
this.bindMethod=function(method,scope){
return function(){
method.apply(scope,arguments);
}
},
this.appendChildProxyFrame=function(protocol){
var proxyName='wufooProxyFrame'+this.formHash;
__proxyFrameUrl=this.getChildProxyUrl(protocol);
this.appendIFrame(proxyName,__proxyFrameUrl);
},
this.getChildProxyUrl=function(protocol){
var url='';
url+=protocol+'//';
url+=this.userName+'.'+this.host+'/forms/blank.htm';
url+='#'+window.location.href;
return url;
},
this.appendIFrame=function(name,src){
var proxyFrame=document.getElementById(name);
if(!proxyFrame){
var newiframe=document.createElement('iframe');
newiframe.setAttribute('id',name);
newiframe.setAttribute('name',name);
newiframe.setAttribute('height','0px;');
newiframe.setAttribute('style','position: absolute; left: -500px; top: 500px; width: 0px;');
newiframe.setAttribute('src',src);
document.body.appendChild(newiframe);
}
}
}
var __currentHeight=0;
var __wufooCallBackFn='';
function __poll(formHash){
var childFrameHeight=__getChildFrameHeight();
if((childFrameHeight>0)&&(__currentHeight!=childFrameHeight)){
__currentHeight=childFrameHeight;
document.getElementById('wufooForm'+formHash).height=childFrameHeight;
if(typeof __wufooCallBackFn==="function"){
__wufooCallBackFn(childFrameHeight);
}
}
setTimeout("__poll('"+formHash+"')",500);
}
function __getChildFrameHeight(){
var hArray=window.location.hash.split('=');
return hArray[1];
}