// -------------------------------------------------------------------
// 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
    this.collapsePrev = false //Default: Collapse previous content each time
    this.enablePersist = false //Default: Disable session only persistence
    //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() : ""
}

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

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

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

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


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

// -------------------------------------------------------------------
// 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() {
    var expandedindices = [] //Array to hold indices (position) of content to be expanded by default
    //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]
    this.expandedindices = expandedindices.join(",") //convert array into a string of the format: "0,2,3" for later parsing by script
}


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

// -------------------------------------------------------------------
// 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"
// -------------------------------------------------------------------

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


//PRIVATE: init()- Initializes Switch Content function (collapse contents by default unless exception is found)
switchcontent.prototype.init = function() {
    var instanceOf = this
    this.collectElementbyClass(this.className) //Get all headers and its corresponding content based on shared class name of contents
    if (this.headers.length == 0)
        return //If no headers are present (no contents to switch), just exit
    // 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 (typeof this.statusOpen != "undefined") //If open/ closing HTML indicator is enabled/ set
            this.headers[i].innerHTML = '<span class="status"></span>' + this.headers[i].innerHTML //Add a span element to original HTML to store indicator
        if (opencontents_ids.indexOf(',' + i + ',') != -1) { //(2) if index "i" exists within cookie string or default-enabled string (i=position of the content to expand)
            this.expandcontent(this.headers[i]) //Expand each content per stored indices (if ""Collapse Previous" is set, only one content)
            if (this.collapsePrev) //If "Collapse Previous" set
                this.prevHeader = this.headers[i]  //Indicate the expanded content's corresponding header as the last clicked on header (for logic purpose)
        }
        else //else if no indices found in stored string
            this.contractcontent(this.headers[i]) //Contract each content by default
        this.headers[i].onclick = function() { instanceOf.toggledisplay(this) }
    }
    if (this.enablePersist)
        switchcontent.dotask(window, function() { instanceOf.rememberpluscleanup() }, "unload") //Call persistence method onunload
}

// -------------------------------------------------------------------
// 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
// -------------------------------------------------------------------
switchcontent.prototype.rememberpluscleanup = function() { //store index of opened ULs relative to other ULs in Tree into cookie
    // 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)))
            opencontents[opencontents.length] = i //save the index of the opened UL (relative to the entire list of ULs) as an array element
        this.headers[i].onclick = null //Cleanup code
    }
    if (opencontents.length > 1) //If there exists open content to be persisted
        opencontents.shift() //Boot the "none" value from the array, so all it contains are the ids of the open contents
    if (typeof this.statusOpen != "undefined") //Cleanup code
        this.statusOpen = this.statusClosed = null //Cleanup code
    switchcontent.setCookie(this.className, opencontents.join(",")) //populate cookie with indices of open contents: classname=1,2,3,etc
}

// -------------------------------------------------------------------
// A few utility functions below:
// -------------------------------------------------------------------
switchcontent.dotask = function(target, functionref, tasktype) { //assign a function to execute to an event handler (ie: onunload)
    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) {
    var re = new RegExp(Name + "=[^;]+", "i"); //construct RE to search for target name/value pair
    if (document.cookie.match(re)) //if cookie found
        return document.cookie.match(re)[0].split("=")[1] //return its value
    return ""
}

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