//write out CSS for class ".hidepiece" that hides pieces of contents within pages
document.write('<style type="text/css">' 
 +'.hidepiece{display:none}\n'
 +'@media print{.hidepiece{display:block !important;}}\n'
 +'</style>')
 
function virtualpaginate(config){ //config: {piececlass:, piececontainer:, pieces_per_page:, defaultpage:, wraparound:, persist}
 this.piececlass=config.piececlass
 var elementType=(typeof config.piececontainer=="undefined")? "div" : config.piececontainer //The type of element used to divide up content into pieces. Defaults to "div"
 this.pieces=virtualpaginate.collectElementbyClass(config.piececlass, elementType) //get total number of divs matching class name
 //Set this.chunksize: 1 if "chunksize" param is undefined, "chunksize" if it's less than total pieces available, or simply total pieces avail (show all)
 this.chunksize=(typeof config.pieces_per_page=="undefined")? 1 : (config.pieces_per_page>0 && config.pieces_per_page<this.pieces.length)? config.pieces_per_page : this.pieces.length
 this.pagecount=Math.ceil(this.pieces.length/this.chunksize) //calculate number of "pages" needed to show the divs
 this.wraparound=config.wraparound || false
 this.paginatediv=[], this.flatviewlinks=[], this.cpspan=[], this.selectmenu=[], this.prevlinks=[], this.nextlinks=[]
 this.persist=config.persist
 var persistedpage=virtualpaginate.getCookie("dd_"+this.piececlass) || 0
 var urlselectedpage=virtualpaginate.urlparamselect(this.piececlass) //returns null or index from: mypage.htm?piececlass=index
 this.currentpage=(typeof urlselectedpage=="number")? urlselectedpage : ((this.persist)? persistedpage : config.defaultpage)
 this.currentpage=(this.currentpage<this.pagecount)? parseInt(this.currentpage) : 0 //ensure currentpage is within range of available pages
 this.showpage(this.currentpage) //Show selected page
}

// -------------------------------------------------------------------
// PUBLIC: navigate(keyword)- Calls this.showpage() based on parameter passed (0=page1, 1=page2 etc, "next", "first", or "last")
// -------------------------------------------------------------------

virtualpaginate.prototype.navigate=function(keyword){
 if ((!this.wraparound && keyword=="previous" && this.currentpage==0) || (!this.wraparound && keyword=="next" && this.currentpage==this.pagecount-1))
  return //exit immediately if wraparound is disabled and prev link is clicked when on 1st content or last link is clicked when on final content
 var prevlinkindex=this.currentpage //Get index of last clicked on page
 if (keyword=="previous")
  this.currentpage=(this.currentpage>0)? this.currentpage-1 : (this.currentpage==0)? this.pagecount-1 : 0
 else if (keyword=="next")
  this.currentpage=(this.currentpage<this.pagecount-1)? this.currentpage+1 : 0
 else if (keyword=="first")
  this.currentpage=0
 else if (keyword=="last")
  this.currentpage=this.pagecount-1 //last page number
 else
  this.currentpage=parseInt(keyword)
 this.currentpage=(this.currentpage<this.pagecount)? this.currentpage : 0 //ensure pagenumber is within range of available pages
 this.showpage(this.currentpage)
 for (var p=0; p<this.paginatediv.length; p++){ //loop through all pagination DIVs
  if (this.flatviewpresent)
   this.flatviewlinks[p][prevlinkindex].className="" //"Unhighlight" previous page (before this.currentpage increments)
  if (this.selectmenupresent)
   this.selectmenu[p].selectedIndex=this.currentpage
  if (this.flatviewpresent)
   this.flatviewlinks[p][this.currentpage].className="selected" //"Highlight" current page
 }
 if (!this.wraparound){
  for (var i=0; i<this.prevlinks.length; i++) //add or remove "disable" class from prev links depending on current page number
   virtualpaginate.setcssclass(this.prevlinks[i], "disabled", (this.currentpage==0)? "add" : "remove")
  for (var i=0; i<this.nextlinks.length; i++) //add or remove "disable" class from next links depending on current page number
   virtualpaginate.setcssclass(this.nextlinks[i], "disabled", (this.currentpage==(this.pagecount-1))? "add" : "remove")
 }
}


// -------------------------------------------------------------------
// PUBLIC: buildpagination()- Create pagination interface by calling one or more of the paginate_build_() functions
// -------------------------------------------------------------------

virtualpaginate.prototype.buildpagination=function(divids, optnavtext){
 var divids=(typeof divids=="string")? [divids] : divids //force divids to be an array of ids
 var primarypaginatediv=divids.shift() //get first id within divids[]
 var paginaterawHTML=document.getElementById(primarypaginatediv).innerHTML
 this.paginate_build(primarypaginatediv, 0, optnavtext)
 for (var i=0; i<divids.length; i++){
  document.getElementById(divids[i]).innerHTML=paginaterawHTML
  this.paginate_build(divids[i], i+1, optnavtext)
 }
}

// -------------------------------------------------------------------
// PRIVATE utility functions
// -------------------------------------------------------------------

virtualpaginate.collectElementbyClass=function(classname, element){ //Returns an array containing DIVs with specified classname. Requires setcssclass()
 if (document.querySelectorAll){
  var pieces=document.querySelectorAll(element+"."+classname) //return pieces as HTMLCollection
 }
 else{
  var pieces=[]
  var alltags=document.getElementsByTagName(element)
  for (var i=0; i<alltags.length; i++){
   if (virtualpaginate.setcssclass(alltags[i], classname, "check")) //if element carries class name in question
    pieces[pieces.length]=alltags[i] //return pieces as array
  }
 }
 return pieces
}

// -------------------------------------------------------------------
// PRIVATE: setcssclass() method- Checks, Add, or Removes a class from an element
// -------------------------------------------------------------------

virtualpaginate.setcssclass=function(el, targetclass, action){
 var needle=new RegExp("(^|\\s+)"+targetclass+"($|\\s+)", "ig")
 if (action=="check")
  return needle.test(el.className)
 else if (action=="remove")
  el.className=el.className.replace(needle, "")
 else if (action=="add" && !needle.test(el.className))
  el.className+=" "+targetclass
}

virtualpaginate.urlparamselect=function(vpclass){
 var result=window.location.search.match(new RegExp(vpclass+"=(\\d+)", "i")) //check for "?piececlass=2" in URL
 return (result==null)? null : parseInt(RegExp.$1) //returns null or index, where index (int) is the selected virtual page's index
}

virtualpaginate.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 null
}

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

// -------------------------------------------------------------------
// PRIVATE: showpage(pagenumber)- Shows a page based on parameter passed (0=page1, 1=page2 etc)
// -------------------------------------------------------------------

virtualpaginate.prototype.showpage=function(pagenumber){
 var totalitems=this.pieces.length //total number of broken up divs
 var showstartindex=pagenumber*this.chunksize //array index of div to start showing per pagenumber setting
 var showendindex=showstartindex+this.chunksize-1 //array index of div to stop showing after per pagenumber setting
 for (var i=0; i<totalitems; i++){
  if (i>=showstartindex && i<=showendindex)
   this.pieces[i].style.display="block"
  else
   this.pieces[i].style.display="none"
 }
 if (this.persist){ //if persistence enabled
  virtualpaginate.setCookie("dd_"+this.piececlass, this.currentpage)
 }
 if (this.cpspan.length>0){ //if <span class="paginateinfo> element is present, update it with the most current info (ie: Page 3/4)
  for (var p=0; p<this.cpspan.length; p++)
   this.cpspan[p].innerHTML='Page '+(this.currentpage+1)+'/'+this.pagecount
 }
}

// -------------------------------------------------------------------
// PRIVATE: build() methods- Various methods to create pagination interfaces
// paginate_paginate_build()- Main build() paginate function
// paginate_output_flatview()- Accepts <span class="flatview"> element and populates it with sequential pagination links
// paginate_paginate_build_flatview()- Parses the modified <span class="flatview"> element and assigns click behavior to the pagination links
// paginate_build_selectmenu(paginatedropdown)- Accepts an empty SELECT element and turns it into pagination menu
// paginate_build_regularlinks(paginatelinks)- Accepts a collection of links and screens out/ creates pagination out of ones with specific "rel" attr
// paginate_build_cpinfo(cpspan)- Accepts <span class="paginateinfo"> element and displays current page info (ie: Page 1/4)
// -------------------------------------------------------------------

virtualpaginate.prototype.paginate_build=function(divid, divpos, optnavtext){
 var instanceOfBox=this
 var paginatediv=document.getElementById(divid)
 if (this.chunksize==this.pieces.length){ //if user has set to display all pieces at once, no point in creating pagination div
  paginatediv.style.display="none"
  return
 }
 var paginationcode=paginatediv.innerHTML //Get user defined, "unprocessed" HTML within paginate div
 if (paginatediv.getElementsByTagName("select").length>0) //if there's a select menu in div
  this.paginate_build_selectmenu(paginatediv.getElementsByTagName("select")[0], divpos, optnavtext)
 if (paginatediv.getElementsByTagName("a").length>0) //if there are links defined in div
  this.paginate_build_regularlinks(paginatediv.getElementsByTagName("a"))
 var allspans=paginatediv.getElementsByTagName("span") //Look for span tags within passed div
 for (var i=0; i<allspans.length; i++){
  if (allspans[i].className=="flatview")
   this.paginate_output_flatview(allspans[i], divpos, optnavtext)
  else if (allspans[i].className=="paginateinfo")
   this.paginate_build_cpinfo(allspans[i], divpos)
 }
 this.paginatediv[divpos]=paginatediv
}

virtualpaginate.prototype.paginate_output_flatview=function(flatviewcontainer, divpos, anchortext){
 var flatviewhtml=""
 var anchortext=anchortext || new Array()
 for (var i=0; i<this.pagecount; i++){
  if (typeof anchortext[i]!="undefined") //if custom anchor text for this link exists
   flatviewhtml+='<a href="#flatview" rel="'+i+'">'+anchortext[i]+'</a> ' //build pagination link using custom anchor text
  else
   flatviewhtml+='<a href="#flatview" rel="'+i+'">'+(i+1)+'</a> ' //build pagination link using auto incremented sequential number instead
 }
 flatviewcontainer.innerHTML=flatviewhtml
 this.paginate_build_flatview(flatviewcontainer, divpos, anchortext)
}

virtualpaginate.prototype.paginate_build_flatview=function(flatviewcontainer, divpos, anchortext){
 var instanceOfBox=this
 var flatviewhtml=""
 this.flatviewlinks[divpos]=flatviewcontainer.getElementsByTagName("a")
 for (var i=0; i<this.flatviewlinks[divpos].length; i++){
  this.flatviewlinks[divpos][i].onclick=function(){
   var prevlinkindex=instanceOfBox.currentpage //Get index of last clicked on flatview link
   var curlinkindex=parseInt(this.getAttribute("rel"))
   instanceOfBox.navigate(curlinkindex)
   return false
  }
 }
 this.flatviewlinks[divpos][this.currentpage].className="selected" //"Highlight" current flatview link
 this.flatviewpresent=true //indicate flat view links are present
}

virtualpaginate.prototype.paginate_build_selectmenu=function(paginatedropdown, divpos, anchortext){
 var instanceOfBox=this
 var anchortext=anchortext || new Array()
 this.selectmenupresent=1
 for (var i=0; i<this.pagecount; i++){
  if (typeof anchortext[i]!="undefined") //if custom anchor text for this link exists, use anchor text as each OPTION's text
   paginatedropdown.options[i]=new Option(anchortext[i], i)
  else //else, use auto incremented, sequential numbers
   paginatedropdown.options[i]=new Option("Page "+(i+1)+" of "+this.pagecount, i)
 }
 paginatedropdown.selectedIndex=this.currentpage
 setTimeout(function(){paginatedropdown.selectedIndex=instanceOfBox.currentpage}, 500) //refresh currently selected option (for IE's sake)
 paginatedropdown.onchange=function(){
 instanceOfBox.navigate(this.selectedIndex)
 }
 this.selectmenu[divpos]=paginatedropdown
 this.selectmenu[divpos].selectedIndex=this.currentpage //"Select" current page's corresponding option
}

virtualpaginate.prototype.paginate_build_regularlinks=function(paginatelinks){
 var instanceOfBox=this
 for (var i=0; i<paginatelinks.length; i++){
  var currentpagerel=paginatelinks[i].getAttribute("rel")
  if (/^(previous)|(next)|(first)|(last)$/.test(currentpagerel)){ //screen for these "rel" values
   paginatelinks[i].onclick=function(){
    instanceOfBox.navigate(this.getAttribute("rel"))
    return false
   }
  }
  if (currentpagerel=="previous" || paginatelinks[i].href.indexOf("previous")!=-1){ //check if this is a "previous" link
   if (!this.wraparound && this.currentpage==0) //if current page is first page, disable "prev" link
    virtualpaginate.setcssclass(paginatelinks[i], "disabled", "add")
   this.prevlinks.push(paginatelinks[i])
  }
  else if (currentpagerel=="next" || paginatelinks[i].href.indexOf("next")!=-1){ //check if this is a "next" link
   if (!this.wraparound && this.currentpage==this.pagecount-1) //if current page is last page, disable "next" link
    virtualpaginate.setcssclass(paginatelinks[i], "disabled", "add")
   this.nextlinks.push(paginatelinks[i])
  }
  
 }
}

virtualpaginate.prototype.paginate_build_cpinfo=function(cpspan, divpos){
 this.cpspan[divpos]=cpspan
 cpspan.innerHTML='Page '+(this.currentpage+1)+'/'+this.pagecount
}