// -------------------------------------------------------------------
// Virtual Pagination Script- By Dynamic Drive, available at: http://www.dynamicdrive.com
// Last updated: May 31st, 2007
//
// PUBLIC: virtualpaginate(className, chunksize)
// Main Virtual Paginate Object function.
// -------------------------------------------------------------------

function virtualpaginate(className, chunksize, elementType)
{
 var elementType=(typeof elementType=="undefined")? "div" : elementType //The type of element used to divide up content into pieces. Defaults to "div"
 //this.pieces=getWords(document.documentElement))
 //Document.write(this.pieces)
 this.pieces=virtualpaginate.collectElementbyClass(className, elementType) //get total number of divs matching class name
 //var numWords = countWords(document.documentElement))
 //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 chunksize=="undefined")? 1 : (chunksize>0 && chunksize <this.pieces.length)? chunksize : this.pieces.length
 //this.chunksize = (typeof chunksize=="undefined")? 1 : (chunksize>0 && chunksize<numWords)? chunksize : numWords
 this.pagecount=Math.ceil(this.pieces.length/this.chunksize) //calculate number of "pages" needed to show the divs
 this.showpage(-1) //show no pages (aka hide all)
 this.currentpage=0 //Having hidden all pages, set currently visible page to 1st page
 this.showpage(this.currentpage) //Show first page
}

function getWords(src)
{
 var wc = 0, words = "";
 traverse(src);
 var w_a = words.match(/\b\w+\b/g);
 if (w_a != null)
 {
  wc = w_a.length;
 }
 function traverse(node)
 {
  if (node.nodeType == 3)
  {
   words += node.nodeValue;
  }
  if (node.childNodes != null)
  {
   for ( var i = 0; i < node.childNodes.length; i++)
   {
    traverse(node.childNodes.item(i));
   }
  }
 }
 return w_a;
}

// -------------------------------------------------------------------
// PRIVATE: collectElementbyClass(classname)- Returns an array containing DIVs with the specified classname
// -------------------------------------------------------------------

virtualpaginate.collectElementbyClass=function(classname, element)
{ //Returns an array containing DIVs with specified classname
 var classnameRE=new RegExp("(^|\\s+)"+classname+"($|\\s+)", "i") //regular expression to screen for classname within element
 var pieces=[]
 var alltags=document.getElementsByTagName(element)
 for (var i=0; i<alltags.length; i++)
 {
  if (typeof alltags[i].className=="string" && alltags[i].className.search(classnameRE)!=-1)
  {
   pieces[pieces.length]=alltags[i]
  }
 }
 return pieces
}

// -------------------------------------------------------------------
// PUBLIC: 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"
  }
 }
 this.currentpage=parseInt(pagenumber)
 if (this.cpspan) //if <span class="paginateinfo> element is present, update it with the most current info (ie: Page 3/4)
 {
  this.cpspan.innerHTML='Page '+(this.currentpage+1)+'/'+this.pagecount
 }
}

// -------------------------------------------------------------------
// PRIVATE: paginate_build_() methods- Various methods to create pagination interfaces
// 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_flatview(flatviewcontainer)- Accepts <span class="flatview"> element and replaces it with sequential pagination links
// paginate_build_cpinfo(cpspan)- Accepts <span class="paginateinfo"> element and displays current page info (ie: Page 1/4)
// -------------------------------------------------------------------

virtualpaginate.prototype.paginate_build_selectmenu=function(paginatedropdown, 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
 paginatedropdown.onchange=function()
 {
  instanceOfBox.showpage(this.selectedIndex)
 }
}

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 (currentpagerel=="previous" || currentpagerel=="next" || currentpagerel=="first" || currentpagerel=="last") //screen for these "rel" values
  {
   paginatelinks[i].onclick=function()
   {
    instanceOfBox.navigate(this.getAttribute("rel"))
    return false
   }
  }
 }
}

virtualpaginate.prototype.paginate_build_flatview=function(flatviewcontainer, anchortext)
{
 var instanceOfBox=this
 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.flatviewlinks=flatviewcontainer.getElementsByTagName("a")
 for (var i=0; i<this.flatviewlinks.length; i++)
 {
  this.flatviewlinks[i].onclick=function()
  {
   instanceOfBox.flatviewlinks[instanceOfBox.currentpage].className="" //"Unhighlight" last flatview link clicked on...
   this.className="selected" //while "highlighting" currently clicked on flatview link (setting its class name to "selected"
   instanceOfBox.showpage(this.getAttribute("rel"))
   return false
  }
 }
 this.flatviewlinks[this.currentpage].className="selected" //"Highlight" current page
 this.flatviewpresent=true //indicate flat view links are present
}

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


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

virtualpaginate.prototype.buildpagination=function(divid, 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], 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_build_flatview(allspans[i], optnavtext)
  }
  else if (allspans[i].className=="paginateinfo")
  {
   this.paginate_build_cpinfo(allspans[i])
  }
 }
 this.paginatediv=paginatediv
}

// -------------------------------------------------------------------
// PRIVATE: navigate(keyword)- Calls this.showpage() with the currentpage property preset based on entered keyword
// -------------------------------------------------------------------

virtualpaginate.prototype.navigate=function(keyword)
{
 if (this.flatviewpresent)
 {
  this.flatviewlinks[this.currentpage].className="" //"Unhighlight" previous page (before this.currentpage increments)
 }
 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.pieces.length-1
 }
 this.showpage(this.currentpage)
 if (this.selectmenupresent)
 {
  this.paginatediv.getElementsByTagName("select")[0].selectedIndex=this.currentpage
 }
 if (this.flatviewpresent)
 {
  this.flatviewlinks[this.currentpage].className="selected" //"Highlight" current page
 }
}