// ---------------------------------------------------------------
// Switch Content Script- By Dynamic Drive
// available at: http://www.dynamicdrive.com
// Created: Jan 5th, 2007
// Last updated: Jan 25th, 2007.
// Fixed defaultExpanded() feature not working when persistence
//   is enabled (applicable only for 1st page load)
// ---------------------------------------------------------------

function switchcontent(className){
	this.className=className
	//Default: Collapse previous content each time
	this.collapsePrev=false
	//Default: Disable session only persistence
	this.enablePersist=false
	//Limit type of element to scan for on page for switch contents
	//if 2nd function parameter is defined,
	// for efficiency sake (ie: "div")
	this.filter_content_tag=(arguments.length==2)? arguments[1].toLowerCase() : ""
}

//PUBLIC: Set open/ closing HTML indicator. Optional
switchcontent.prototype.setStatus=function(openHTML, closeHTML){
	this.statusOpen=openHTML
	this.statusClosed=closeHTML
}

//PUBLIC: Set open/ closing color of switch header. Optional
switchcontent.prototype.setColor=function(openColor, closeColor){
	this.colorOpen=openColor
	this.colorClosed=closeColor
}

//PUBLIC: Enable/ disable persistence. Default is true.
switchcontent.prototype.setPersist=function(bool){
	this.enablePersist=bool
}

//PUBLIC: Enable/ disable collapse previous content. Default is false.
switchcontent.prototype.collapsePrevious=function(bool){
	this.collapsePrev=bool
}


//PUBLIC: Expand / contract all contents method.
// (Values: "contract"|"expand")
switchcontent.prototype.sweepToggle=function(setting){
	//if there are switch contents defined on the page
	if (typeof this.headers!="undefined" && this.headers.length>0){
		for (var i=0; i<this.headers.length; i++){
			if (setting=="expand")
				//expand each content
				this.expandcontent(this.headers[i])
			else if (setting=="contract")
				//contract each content
				this.contractcontent(this.headers[i])
		}
	}
}


// -------------------------------------------------------
// PUBLIC: defaultExpanded(indices_of_contents)
// - Set contents that should be expanded by default
// when the page loads.
// Note that the persistence feature (if enabled)
// overrides this setting.
// Pass in the position of the contents relative
// to the rest of the contents
// ie: defaultExpanded(0,2,3) would expand the 1st, 3rd,
// and 4th contents by default
// -------------------------------------------------------

switchcontent.prototype.defaultExpanded=function(){
	//Array to hold indices (position)
	// of content to be expanded by default
	var expandedindices=[]
	//Loop through function arguments,
	// and store each one within array
	//Two test conditions: 1) End of Arguments array,
	// or 2) If "collapsePrev" is enabled,
	// only the first entered index
	// (as only 1 content can be expanded at any time)
	for (var i=0; (!this.collapsePrev && i<arguments.length) || (this.collapsePrev && i==0); i++)
		expandedindices[expandedindices.length]=arguments[i]
	//convert array into a string of the format: "0,2,3"
	// for later parsing by script
	this.expandedindices=expandedindices.join(",")
}


//PRIVATE: Sets color of switch header.
switchcontent.prototype.togglecolor=function(header, status){
	if (typeof this.colorOpen!="undefined")
		header.style.color=status
}


//PRIVATE: Sets status indicator HTML of switch header.
switchcontent.prototype.togglestatus=function(header, status){
	if (typeof this.statusOpen!="undefined")
		header.firstChild.innerHTML=status
}


//PRIVATE: Contracts a content
// based on its corresponding header entered
switchcontent.prototype.contractcontent=function(header){
	//Reference content for this header
	var innercontent=document.getElementById(header.id.replace("-title", ""))
	innercontent.style.display="none"
	this.togglestatus(header, this.statusClosed)
	this.togglecolor(header, this.colorClosed)
}


//PRIVATE: Expands a content based on its corresponding header entered
switchcontent.prototype.expandcontent=function(header){
	var innercontent=document.getElementById(header.id.replace("-title", ""))
	innercontent.style.display="block"
	this.togglestatus(header, this.statusOpen)
	this.togglecolor(header, this.colorOpen)
}

// -----------------------------------------------------------
// PRIVATE: toggledisplay(header)
//- Toggles between a content being expanded or contracted
// If "Collapse Previous" is enabled,
// contracts previous open content before expanding current
// -----------------------------------------------------------

switchcontent.prototype.toggledisplay=function(header){
	//Reference content for this header
	var innercontent=document.getElementById(header.id.replace("-title", ""))
	if (innercontent.style.display=="block")
		this.contractcontent(header)
	else{
		this.expandcontent(header)
		// If "Collapse Previous" is enabled
		// and there's a previous open content
		if (this.collapsePrev && typeof this.prevHeader!="undefined" && this.prevHeader.id!=header.id)
			//Contract that content first
			this.contractcontent(this.prevHeader)
	}
	if (this.collapsePrev)
		//Set current expanded content as the next "Previous Content"
		this.prevHeader=header
}


// -------------------------------------------------------------
// PRIVATE: collectElementbyClass()
// - Searches and stores all switch contents
// (based on shared class name) and their headers in two arrays
// Each content should carry an unique ID, and for its header,
// an ID equal to "CONTENTID-TITLE"
// -------------------------------------------------------------

//Returns an array containing DIVs with specified classname
switchcontent.prototype.collectElementbyClass=function(classname){
	//regular expression to screen for classname within element
	var classnameRE=new RegExp("(^|\\s+)"+classname+"($|\\s+)", "i")
	this.headers=[], this.innercontents=[]
	//If user defined limit type of element to scan
	// for to a certain element (ie: "div" only)
	if (this.filter_content_tag!="")
		var allelements=document.getElementsByTagName(this.filter_content_tag)
	else //else, scan all elements on the page!
		var allelements=document.all? document.all : document.getElementsByTagName("*")
	for (var i=0; i<allelements.length; i++){
		if (typeof allelements[i].className=="string" && allelements[i].className.search(classnameRE)!=-1){
			//if header exists for this inner content
			if (document.getElementById(allelements[i].id+"-title")!=null){
				//store reference to header intended for this inner content
				this.headers[this.headers.length]=document.getElementById(allelements[i].id+"-title")
				//store reference to this inner content
				this.innercontents[this.innercontents.length]=allelements[i]
			}
		}
	}
}


//PRIVATE: init()
// - Initializes Switch Content function
// (collapse contents by default unless exception is found)

switchcontent.prototype.init=function(){
	var instanceOf=this
	//Get all headers and its corresponding content
	// based on shared class name of contents
	this.collectElementbyClass(this.className)
	if (this.headers.length==0)
		//If no headers are present (no contents to switch), just exit
		return
	// Get ids of open contents below. Three possible scenerios:
	// 1) Persistence is enabled AND corresponding cookie contains a non blank ("") string, indicating this isn't the first page load
	// 2) Or, check to see if there are contents that should be enabled by default (even if persistence is enabled and this IS the first page load)
	// 3) Or, default to no contents should be expanded on page load ("" value)
	var opencontents_ids=(this.enablePersist && switchcontent.getCookie(this.className)!="")? ','+switchcontent.getCookie(this.className)+',' : (this.expandedindices)? ','+this.expandedindices+',' : ""

	for (var i=0; i<this.headers.length; i++){ //BEGIN FOR LOOP (1)
		//If open/ closing HTML indicator is enabled/ set
		if (typeof this.statusOpen!="undefined")
			//Add a span element to original HTML to store indicator
			this.headers[i].innerHTML='<span class="status"></span>'+this.headers[i].innerHTML
		//(2) if index "i" exists within cookie string or
		// default-enabled string (i=position of the content to expand)
		if (opencontents_ids.indexOf(','+i+',')!=-1){
			//Expand each content per stored indices
			// (if ""Collapse Previous" is set, only one content)
			this.expandcontent(this.headers[i])
			if (this.collapsePrev) //If "Collapse Previous" set
				//Indicate the expanded content's corresponding header
				// as the last clicked on header (for logic purpose)
				this.prevHeader=this.headers[i]
		}
		else //else if no indices found in stored string
			//Contract each content by default
			this.contractcontent(this.headers[i])
		this.headers[i].onclick=function(){instanceOf.toggledisplay(this)}
	}
	if (this.enablePersist)
		//Call persistence method onunload
		switchcontent.dotask(window, function(){instanceOf.rememberpluscleanup()}, "unload")
}


// --------------------------------------------------------
// PRIVATE: rememberpluscleanup()
// - Stores the indices of content that are expanded
// inside session only cookie
// If "Collapse Previous" is enabled,
// only 1st expanded content index is stored
// --------------------------------------------------------

//store index of opened ULs relative to other ULs in Tree into cookie
switchcontent.prototype.rememberpluscleanup=function(){
	// Define array to hold ids of open content that should be persisted
	// Default to just "none" to account for the case where
	// no contents are open when user leaves the page (and persist that):
	var opencontents=new Array("none")
	for (var i=0; i<this.innercontents.length; i++){
		//If persistence enabled, content in question is expanded,
		// and either "Collapse Previous" is disabled, or if enabled,
		// this is the first expanded content
		if (this.enablePersist && this.innercontents[i].style.display=="block" && (!this.collapsePrev || (this.collapsePrev && opencontents.length<2)))
			//save the index of the opened UL (relative to the entire
			// list of ULs) as an array element
			opencontents[opencontents.length]=i
		this.headers[i].onclick=null //Cleanup code
	}
	//If there exists open content to be persisted
	if (opencontents.length>1)
		//Boot the "none" value from the array,
		// so all it contains are the ids of the open contents
		opencontents.shift()
	if (typeof this.statusOpen!="undefined") //Cleanup code
		this.statusOpen=this.statusClosed=null //Cleanup code
	//populate cookie with indices of open contents: classname=1,2,3,etc
	switchcontent.setCookie(this.className, opencontents.join(","))
}


// -----------------------------------------
// A few utility functions below:
// -----------------------------------------


//assign a function to execute to an event handler (ie: onunload)
switchcontent.dotask=function(target, functionref, tasktype){
	var tasktype=(window.addEventListener)? tasktype : "on"+tasktype
	if (target.addEventListener)
		target.addEventListener(tasktype, functionref, false)
	else if (target.attachEvent)
		target.attachEvent(tasktype, functionref)
}

switchcontent.getCookie=function(Name){ 
	//construct RE to search for target name/value pair
	var re=new RegExp(Name+"=[^;]+", "i");
	if (document.cookie.match(re)) //if cookie found
		//return its value
		return document.cookie.match(re)[0].split("=")[1]
	return ""
}

switchcontent.setCookie=function(name, value){
	document.cookie = name+"="+value
}