Home >Backend Development >XML/RSS Tutorial >XML volume practical tips (3): dynamic paging
XML volume practical tips (3): dynamic paging
- 黄舟Original
- 2017-02-10 16:16:291730browse
Motivation:
In order to facilitate users to view large batches of data, we will use dynamic paging, so the paging function is the most common and commonly used functional module we have seen on the website. In the past, information paging was connected to the database, and every click required the support of the background database. This not only increases the burden on the server, but also seriously affects the user's browsing speed.
Just imagine, if the paging function is put on the client, what kind of effect will it have? Haha, take a look at the design below! .
Materials:
XML Volume Dynamic Paging
There are 2 files: pages.xml and pages.xsl
Function:
Put the paging function on the client . Filter data without refreshing the page, effectively improving the efficiency of browsing data.
Effect:
Browse here
Code:
pages.xml
<?xml version="1.0" encoding="gb2312" ?>
<?xml-stylesheet type="text/xsl" href="pages.xsl" ?>
<BlueIdea>
<team>
<blue_ID>1</blue_ID>
<blue_name>Sailflying</blue_name>
<blue_text>一个简单的分页</blue_text>
<blue_time>2002-1-11 17:35:33</blue_time>
<blue_class>XML专题</blue_class>
</team>
<team>
<blue_ID>2</blue_ID>
<blue_name>flyingbird</blue_name>
<blue_text>嫁给你，是要你疼的</blue_text>
<blue_time>2001-09-06 12:45:51</blue_time>
<blue_class>灌水精华</blue_class>
</team>
<team>
<blue_ID>3</blue_ID>
<blue_name>苛子</blue_name>
<blue_text>正则表达式在ＵＢＢ论坛中的应用</blue_text>
<blue_time>2001-11-23 21:02:16</blue_time>
<blue_class>Web 编程精华</blue_class>
</team>
<team>
<blue_ID>4</blue_ID>
<blue_name>太乙郎</blue_name>
<blue_text>年末经典分舵聚会完全手册 v0.1</blue_text>
<blue_time>2000-12-08 10:22:48</blue_time>
<blue_class>论坛灌水区</blue_class>
</team>
<team>
<blue_ID>5</blue_ID>
<blue_name>mmkk</blue_name>
<blue_text>Asp错误信息总汇</blue_text>
<blue_time>2001-10-13 16:39:05</blue_time>
<blue_class>javascript脚本</blue_class>
</team>
</BlueIdea>
pages.xsl
<?xml version="1.0" encoding="gb2312" ?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/TR/WD-xsl">
<xsl:template match="/">
<html>
<head>
<title> XML卷之实战锦囊（3）：动态分页</title>
<style>
body,BlueIdea,team,blue_ID,blue_name,blue_text,blue_time,blue_class{ font: 12px "宋体", "Arial", "Times New Roman"; }
table { font-size: 12px; border: 0px double; border-color: #99CC99 #99CC99 #CCCCCC #CCCCCC; cellpadding:3;cellspacing:3; bgcolor:#eeeeee; text-decoration: blink}
span { font-size: 12px; color: red; }
.keybutton { cursor:hand; font-size: 12px; color: #003300; background: #ffffff; border: 0px solid;}
</style>
<script>
<xsl:comment>
<![CDATA[
var OnePageNum=2;
var PageNum=1;
var XMLPageNum=1;
function pages(Num)
{
stylesheet=document.XSLDocument;
source=document.XMLDocument;
nodes=source.documentElement.childNodes;
len=nodes.length;
for(i=1;i<=(len/OnePageNum);i++);
XMLPageNum=i;
var firstNum=0;
var lastNume=0;
if (Num=="first") {PageNum=1;}
if (Num=="previous") {if (PageNum>1) PageNum -=1;}
if (Num=="next") {if (PageNum<XMLPageNum) PageNum +=1;}
if (Num=="last") {PageNum =XMLPageNum;}
sortField=document.XSLDocument.selectSingleNode("//@expr");
firstNum=OnePageNum*(PageNum-1)+1;
lastNum=OnePageNum*(PageNum-1)+OnePageNum;
text="childnumber(this)>="+firstNum+" & childnumber(this)<="+lastNum;
sortField.value=text;
Layer1.innerHTML=source.documentElement.transformNode(stylesheet);
}
]]>
</xsl:comment>
</script>
</head>
<body>
<p align="center"><span>XML卷之实战锦囊（3）：动态分页</span></p>
<table align="center" width="500" >
<tr>
<td>
<button id="cmdfirstPage" class="keybutton" onclick="pages('first');" >首页</button>
<button id="cmdpreviousPage" class="keybutton" onclick="pages('previous');" >上一页</button>
<button id="cmdnextPage" class="keybutton" onclick="pages('next');">下一页</button>
<button id="cmdlastPage" class="keybutton" onclick="pages('last');">尾页</button>
</td>
</tr>
</table>
<div id="Layer1" name="Layer1"> <xsl:apply-templates select="BlueIdea" /></div>
</body>
</html>
</xsl:template>
<xsl:template match="BlueIdea">
<table width="500" border="1" align="center" cellpadding="1" cellspacing="1" bordercolordark="#ffffff" bordercolorlight="#ADAAAD">
<tr bgcolor="#FFCC99" align="center">
<td>编号</td>
<td>姓名</td>
<td>主题</td>
<td>发表时间</td>
<td>归类</td>
</tr>
<xsl:apply-templates select="team" order-by="blue_ID"/>
</table>
</xsl:template>
<xsl:template match="team">
<xsl:if expr="childnumber(this)>=1 & childnumber(this)<=2 ">
<tr align="center">
<xsl:apply-templates select="blue_ID" />
<xsl:apply-templates select="blue_name" />
<xsl:apply-templates select="blue_text" />
<xsl:apply-templates select="blue_time" />
<xsl:apply-templates select="blue_class" />
</tr>
</xsl:if>
</xsl:template>
<xsl:template match="blue_ID">
<td bgcolor="#eeeeee">
<xsl:value-of />
</td>
</xsl:template>
<xsl:template match="blue_name">
<td>
<xsl:value-of />
</td>
</xsl:template>
<xsl:template match="blue_text">
<td>
<xsl:value-of />
</td>
</xsl:template>
<xsl:template match="blue_time">
<td>
<xsl:value-of />
</td>
</xsl:template>
<xsl:template match="blue_class">
<td>
<xsl:value-of />
</td>
</xsl:template>
</xsl:stylesheet>
Explanation:
1) search.xml is a data file, I believe everyone will have no problem.
2) search.xsl is a format file, there are several things to pay attention to.
(1) In the script:
nodes=source.documentElement.childNodes;
The function is: find all nodes. nodes.length is the total number of nodes that meet the conditions
sortField=document.XSLDocument.selectSingleNode("//@expr");The function is to find the first node with the attribute expr, so its corresponding node is
<xsl:if expr="childnumber(this)>=1 & childnumber(this)<=2 ">
Therefore, the value of expr during the first onLoad is
childnumber(this)<=1 & childnumber(this)>=2
About> < You may be more familiar with it. what is that? It is "AND".
You can find some others in XML books.
Parameter description:
OnePageNum: The number of data displayed on each page
PageNum: The current page number
XMLPageNum: The total number of pages
firstNum: The first data value of the current page
lastNum: The last data value of the current page
(2) In the text:
<xsl:if expr="childnumber(this)>=1 & childnumber(this)<=2 ">
In paging we need to output the appropriate data, so we use an if judgment condition to control it.
In the initial stage, we require that only the values of the first two nodes be output.
childnumber(this)
Function: Return the number of the current node in its superior node list. The default number of the first node in the list is 1.
In paging, we judge which page it belongs to based on the number of the node.
expr
I don’t know if you have noticed that the first two times we used test, but this time we used expr.
There are certain differences between them, and their usage is also different.
expr ── Script language expression, the calculation result is "true" or "false"; if the result is "true" and passes the test, the content will be displayed in the output (this attribute can be omitted).
test ── Source data test conditions.
<button id="cmdfirstPage" class="keybutton" onclick="pages('first');" >首页</button>
The function is to return the data to the previous page. The other buttons work similarly.
Additional points: How to use XML example files
1) Save the two files in each example separately according to their file names.
2) Just browse the XML file with a browser. This is the effect you will see, it should be good!
Postscript:
Haha, you can add the function of paging after dynamic sorting. Then make the number of lists configurable. Use your imagination to make these functions more perfect. You can research better ways to implement paging functionality. It’s great to discuss with each other!
The above is the practical tips for XML volume (3): the content of dynamic paging. For more related content, please pay attention to the PHP Chinese website (www.php.cn)!