/*
based on prototype's && moo.fx's ajax class
to be used with prototype.lite, in conjunction with moo.AJAX
this submits an iframe invisibly to the server, and expects a JSON object in return
handy, so that you do not have to care about posting forms, urlencoding, file uploads etc.
usage: <form method='post' onsubmit='new iframe(this); return false;'>

changelog:
17-01-06: initial release
18-01-06: added options initiator
          added IE5 support
          added Opera support
01-03-06: added WORKING safari support! Major thanks to Charles Hinshaw and Phil Barrett!

*/
document.iframeLoaders = {};

iframe = Class.create();
iframe.prototype = {
    initialize: function(form, options){
        if (!options) options = {};
        this.form = form;
        this.uniqueId = new Date().getTime();
        document.iframeLoaders[this.uniqueId] = this;
        this.transport = this.getTransport();
        this.onComplete = options.onComplete || null;
        this.update = $(options.update) || null;
        this.updateMultiple = options.multiple || false;
        form.target= 'frame_'+this.uniqueId;
        form.setAttribute("target", 'frame_'+this.uniqueId); // in case the other one fails.
        form.submit();
    },

    onStateChange: function(){
        this.transport = $('frame_'+this.uniqueId);
        try {   var doc = this.transport.contentDocument.document.body.innerHTML; this.transport.contentDocument.document.close(); }    // For NS6
        catch (e){
            try{ var doc = this.transport.contentWindow.document.body.innerHTML; this.transport.contentWindow.document.close(); } // For IE5.5 and IE6
             catch (e){
                 try { var doc = this.transport.document.body.innerHTML; this.transport.document.body.close(); } // for IE5
                    catch (e) {
                        try { var doc = window.frames['frame_'+this.uniqueId].document.body.innerText; } // for really nasty browsers
                        catch (e) { } // forget it.
                 }
            }
        }
        this.transport.responseText = doc;

        if (this.onComplete) setTimeout(function(){this.onComplete(this.transport);}.bind(this), 10);
        if (this.update) setTimeout(function(){this.update.innerHTML = this.transport.responseText;}.bind(this), 10);
        if (this.updateMultiple){ setTimeout(function(){ // JSON support!
                try { var hasscript = false; eval("var inputObject = "+this.transport.responseText);    // we're expecting a JSON object, eval it to inputObject
                    for (var i in inputObject) { if (i == 'script') { hasscript = true; } // check if we passed some javascript along too
                        else {if ( elm = $(i)) { elm.innerHTML = inputObject[i]; } else { alert("element "+i+" not found!"); } } // if it's not script, update the corresponding div
                    } if (hasscript) eval(inputObject['script']); // some on-the-fly-javascript exchanging support too
                } catch (e) { alert('There was an error processing: '+this.transport.responseText); } // in case of an error
            }.bind(this), 10);
        }
    },

    getTransport: function()
    {
        var divElm = document.createElement('DIV');
        divElm.style.position = "absolute";
        divElm.style.top = "0";
        divElm.style.marginLeft = "-10000px";
        if (navigator.userAgent.indexOf('MSIE') > 0 && navigator.userAgent.indexOf('Opera') == -1) {// switch to the crappy solution for IE
         divElm.innerHTML = '<iframe name=\"frame_'+this.uniqueId+'\" id=\"frame_'+this.uniqueId+'\" src=\"about:blank\" onload=\"setTimeout(function(){document.iframeLoaders['+this.uniqueId+'].onStateChange()},20);"></iframe>';
        } else {
            var frame = document.createElement("iframe");
            frame.setAttribute("name", "frame_"+this.uniqueId);
            frame.setAttribute("id", "frame_"+this.uniqueId);
            frame.addEventListener("load",  function(){ this.onStateChange(); }.bind(this), false);
            divElm.appendChild(frame);
        }
        document.getElementsByTagName("body").item(0).appendChild(divElm);
    }
};