jquery.pager.js分页实现详解

/* 
* jQuery pager plugin 
* Version 1.0 (12/22/2008) 
* @requires jQuery v1.2.6 or later 
* 
* Example at: http://jonpauldavies.github.com/JQuery/Pager/PagerDemo.html 
* 
* Copyright (c) 2008-2009 Jon Paul Davies 
* Dual licensed under the MIT and GPL licenses: 
* http://www.opensource.org/licenses/mit-license.php 
* http://www.gnu.org/licenses/gpl.html 
* 
* Read the related blog post and contact the author at http://www.j-dee.com/2008/12/22/jquery-pager-plugin/ 
* 
* This version is far from perfect and doesn't manage it's own state, therefore contributions are more than welcome! 
* 
* Usage: .pager({ pagenumber: 1, pagecount: 15, buttonClickCallback: PagerClickTest }); 
* 
* Where pagenumber is the visible page number 
* pagecount is the total number of pages to display 
* buttonClickCallback is the method to fire when a pager button is clicked. 
* 
* buttonClickCallback signiture is PagerClickTest = function(pageclickednumber) 
* Where pageclickednumber is the number of the page clicked in the control. 
* 
* The included Pager.CSS file is a dependancy but can obviously tweaked to your wishes 
* Tested in IE6 IE7 Firefox & Safari. Any browser strangeness, please report. 
*/ 
(function($) { 
 
 $.fn.pager = function(options) { 
 
 var opts = $.extend({}, $.fn.pager.defaults, options); 
 
 return this.each(function() { 
 
 // empty out the destination element and then render out the pager with the supplied options 
  $(this).empty().append(renderpager(parseInt(options.pagenumber), parseInt(options.pagecount), options.buttonClickCallback)); 
  
  // specify correct cursor activity 
  $('.pages li').mouseover(function() { document.body.style.cursor = "pointer"; }).mouseout(function() { document.body.style.cursor = "auto"; }); 
 }); 
 }; 
 
 // render and return the pager with the supplied options 
 function renderpager(pagenumber, pagecount, buttonClickCallback) { 
 
 // setup $pager to hold render 
 var $pager = $('<ul class="pages"></ul>'); 
 
 // add in the previous and next buttons 
 $pager.append(renderButton('第一页', pagenumber, pagecount, buttonClickCallback)).append(renderButton('上一页', pagenumber, pagecount, buttonClickCallback)); 
 
 // pager currently only handles 5 viewable pages ( could be easily parameterized, maybe in next version ) so handle edge cases 
 var startPoint = 1; 
 var endPoint = 5; 
 
 if (pagenumber > 2) { 
  startPoint = pagenumber - 2; 
  endPoint = pagenumber + 2; 
 } 
 
 if (endPoint > pagecount) { 
  startPoint = pagecount - 3; 
  endPoint = pagecount; 
 } 
 
 if (startPoint < 1) { 
  startPoint = 1; 
 } 
 
 // loop thru visible pages and render buttons 
 for (var page = startPoint; page <= endPoint; page++) { 
 
  var currentButton = $('<li class="page-number">' + (page) + '</li>'); 
 
  page == pagenumber ? currentButton.addClass('pgCurrent') : currentButton.click(function() { buttonClickCallback(this.firstChild.data); }); 
  currentButton.appendTo($pager); 
 } 
 
 // render in the next and last buttons before returning the whole rendered control back. 
 $pager.append(renderButton('下一页', pagenumber, pagecount, buttonClickCallback)).append(renderButton('尾页', pagenumber, pagecount, buttonClickCallback)); 
 
 return $pager; 
 } 
 
 // renders and returns a 'specialized' button, ie 'next', 'previous' etc. rather than a page number button 
 function renderButton(buttonLabel, pagenumber, pagecount, buttonClickCallback) { 
 
 var $Button = $('<li class="pgNext">' + buttonLabel + '</li>'); 
 
 var destPage = 1; 
 
 // work out destination page for required button type 
 switch (buttonLabel) { 
  case "第一页": 
  destPage = 1; 
  break; 
  case "上一页": 
  destPage = pagenumber - 1; 
  break; 
  case "下一页": 
  destPage = pagenumber + 1; 
  break; 
  case "尾页": 
  destPage = pagecount; 
  break; 
 } 
 
 // disable and 'grey' out buttons if not needed. 
 if (buttonLabel == "第一页" || buttonLabel == "上一页") { 
  pagenumber <= 1 ? $Button.addClass('pgEmpty') : $Button.click(function() { buttonClickCallback(destPage); }); 
 } 
 else { 
  pagenumber >= pagecount ? $Button.addClass('pgEmpty') : $Button.click(function() { buttonClickCallback(destPage); }); 
 } 
 
 return $Button; 
 } 
 
 // pager defaults. hardly worth bothering with in this case but used as placeholder for expansion in the next version 
 $.fn.pager.defaults = { 
 pagenumber: 1, 
 pagecount: 1 
 }; 
 
})(jQuery); 

#pager ul.pages { 
display:block; 
border:none; 
text-transform:uppercase; 
font-size:10px; 
margin:10px 0 50px; 
padding:0; 
} 
 
#pager ul.pages li { 
list-style:none; 
float:left; 
border:1px solid #ccc; 
text-decoration:none; 
margin:0 5px 0 0; 
padding:5px; 
} 
 
#pager ul.pages li:hover { 
border:1px solid #003f7e; 
} 
 
#pager ul.pages li.pgEmpty { 
border:1px solid #eee; 
color:#eee; 
} 
 
#pager ul.pages li.pgCurrent { 
border:1px solid #003f7e; 
color:#000; 
font-weight:700; 
background-color:#eee; 
} 

 <html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
 <title>jQuery.pager.js Test</title> 
 <link href="Pager.css" rel="stylesheet" type="text/css" /> 
 <script src="jquery-1.2.6.js" type="text/javascript"></script> 
 <script src="jquery.pager.js" type="text/javascript"></script> 
 <script type="text/javascript" language="javascript"> 
 
 $(document).ready(function() { 
  $("#pager").pager({ pagenumber: 1, pagecount: 15, buttonClickCallback: PageClick }); 
 }); 
 
 PageClick = function(pageclickednumber) { 
  $("#pager").pager({ pagenumber: pageclickednumber, pagecount: 15, buttonClickCallback: PageClick }); 
  $("#result").html("Clicked Page " + pageclickednumber); 
 } 
  
 </script> 
</head> 
<body> 
<h2 id="result">Click the pager below.</h2> 
<div id="pager" ></div> 
</body> 
</html>