PHP操作XML文件学习笔记

对于XML的操作包括遍历，生成，修改，删除等其他类似的操作。PHP对于XML的操作方式很多，这次学习的是通过DOMDocument进行操作，其他的操作方法可以参考 http://www.oschina.net/code/snippet_110138_4727 1.对XML文件的遍历 通过DOMDocument对于XML文件的操

　　对于XML的操作包括遍历，生成，修改，删除等其他类似的操作。PHP对于XML的操作方式很多，这次学习的是通过DOMDocument进行操作，其他的操作方法可以参考

　　http://www.oschina.net/code/snippet_110138_4727

　　1.对XML文件的遍历

　　　　通过DOMDocument对于XML文件的操作的方法：首先要实例化一个DOMDocument类的对象，然后引入要操作的XML文件。即：

<span>1</span> <span>$doc</span> = <span>new</span><span> DOMDocument();
</span><span>2</span> <span>$doc</span>->load("test.xml");

<span></span><span>xml version="1.0" encoding="utf-8" </span><span>?></span>
<span><span>school</span><span>></span>
    <span><span>student</span><span>></span>
        <span><span>name</span><span>></span>张三<span></span><span>name</span><span>></span>
        <span><span>sex</span><span>></span>男<span></span><span>sex</span><span>></span>
        <span><span>age</span><span>></span>19<span></span><span>age</span><span>></span>
    <span></span><span>student</span><span>></span>
    <span><span>student</span><span>></span>
        <span><span>name</span><span>></span>李四<span></span><span>name</span><span>></span>
        <span><span>sex</span><span>></span>女<span></span><span>sex</span><span>></span>
        <span><span>age</span><span>></span>18<span></span><span>age</span><span>></span>
    <span></span><span>student</span><span>></span>
    <span><span>student</span><span>></span>
        <span><span>name</span><span>></span>王五<span></span><span>name</span><span>></span>
        <span><span>sex</span><span>></span>男<span></span><span>sex</span><span>></span>
        <span><span>age</span><span>></span>19<span></span><span>age</span><span>></span>
    <span></span><span>student</span><span>></span>
<span></span><span>school</span><span>></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

<span>1</span> <span>$content</span> = <span>$doc</span>->getElementsByTagName("student"<span>);
</span><span>2</span> <span>foreach</span>(<span>$content</span> <span>as</span> <span>$value</span><span>){
</span><span>3</span>     <span>echo</span> <span>$value</span>->nodeValue."<br>"<span>;
</span><span>4</span> }

　　注意：在遍历XML文件的时候，要注意的一个问题就是编码的问题，如果xml文件的encoding为"utf-8"，那么xml文件的文件编码也必须是utf-8，可以通过文本编辑器将文件另存为和xml的encoding相同的文件编码即可。否则在遍历的时候会报错或者出现乱码。

　　2.生成XML文件

　　　　在生成XML文件的时候，是通过DOMDocument类中的方法来创建各个节点和节点内容的。我通过查询数据库，并将数据库中的信息生成XML文件方法如下：

<span> 1</span> <span>include</span> "database.php";       <span>//</span><span>导入连接数据库文件</span>
<span> 2</span> <span>$query</span> = <span>mysql_query</span>("SELECT * FROM test"<span>);
</span><span> 3</span> 
<span> 4</span> <span>//</span><span>操作xml准备</span>
<span> 5</span> <span>$doc</span> = <span>new</span><span> DOMDocument("1.0","utf-8");
</span><span> 6</span> 
<span> 7</span> <span>//</span><span>通过createElement方法为xml文件创建节点
</span><span> 8</span> <span>//创建根节点</span>
<span> 9</span> <span>$school</span>= <span>$doc</span>->createElement("school"<span>);
</span><span>10</span> <span>//</span><span>11</span> <span>//将根节点添加到xml文件中</span>
<span>12</span> <span>$doc</span>->appendChild(<span>$school</span><span>);
</span><span>13</span> 
<span>14</span> <span>//</span><span>创建student节点</span>
<span>15</span> <span>$student</span>= <span>$doc</span>->createElement("student"<span>);
</span><span>16</span> <span>//</span><span>将student节点添加到school节点下</span>
<span>17</span> <span>$school</span>->appendChild(<span>$student</span><span>);
</span><span>18</span> 
<span>19</span> <span>$nameinfo</span> = <span>array</span>();    <span>//</span>
<span>20</span> <span>$sexinfo</span> = <span>array</span>();       <span>//</span>
<span>21</span> <span>$ageinfo</span> = <span>array</span>();       <span>//</span>
<span>22</span> <span>$idinfo</span> = <span>array</span>();         <span>//</span><span>对应xml文件中属性id的值</span>
<span>23</span> <span>$i</span> = 0;                        <span>//</span><span>控制变量i</span>
<span>24</span> 
<span>25</span> <span>while</span>(<span>$row</span>=<span>mysql_fetch_array</span>(<span>$query</span><span>)){
</span><span>26</span>     <span>//</span><span>27</span> <span>   //查询数据库信息并赋值给相应的数组</span>
<span>28</span>     <span>$nameinfo</span>[<span>$i</span>] = <span>$doc</span>->createTextNode(<span>$row</span>["name"<span>]);
</span><span>29</span>     <span>$sexinfo</span>[<span>$i</span>] = <span>$doc</span>->createTextNode(<span>$row</span>["sex"<span>]);
</span><span>30</span>     <span>$ageinfo</span>[<span>$i</span>] = <span>$doc</span>->createTextNode(<span>$row</span>["age"<span>]);
</span><span>31</span>     <span>$idinfo</span>[<span>$i</span>] = <span>$doc</span>->createTextNode(<span>$i</span><span>);
</span><span>32</span>     <span>$i</span>++<span>;
</span><span>33</span> <span>}
</span><span>34</span> 
<span>35</span> <span>for</span>(<span>$i</span>=0;<span>$i</span>count(<span>$nameinfo</span>);<span>$i</span>++<span>){
</span><span>36</span>     <span>$name</span> = <span>$doc</span>->createElement("name"<span>);
</span><span>37</span>     <span>$sex</span> = <span>$doc</span>->createElement("sex"<span>);
</span><span>38</span>     <span>$age</span> = <span>$doc</span>->createElement("age"<span>);
</span><span>39</span>     <span>//</span>
<span>40</span>     <span>$id</span> = <span>$doc</span>->createAttribute("id"<span>);
</span><span>41</span> 
<span>42</span>     <span>//</span>
<span>43</span>     <span>$student</span>->appendChild(<span>$name</span><span>);
</span><span>44</span>     <span>$student</span>->appendChild(<span>$sex</span><span>);
</span><span>45</span>     <span>$student</span>->appendChild(<span>$age</span><span>);
</span><span>46</span>     <span>$student</span>->appendChild(<span>$id</span><span>);
</span><span>47</span>     
<span>48</span>     <span>//</span>
<span>49</span>     <span>$name</span>->appendChild(<span>$nameinfo</span>[<span>$i</span><span>]);
</span><span>50</span>     <span>$sex</span>->appendChild(<span>$sexinfo</span>[<span>$i</span><span>]);
</span><span>51</span>     <span>$age</span>->appendChild(<span>$ageinfo</span>[<span>$i</span><span>]);
</span><span>52</span>     <span>$id</span>->appendChild(<span>$idinfo</span>[<span>$i</span><span>]);
</span><span>53</span> <span>}
</span><span>54</span> 
<span>55</span> <span>//</span><span>通过save方法将生成的xml文件保存</span>
<span>56</span> <span>$doc</span>->save("test.xml");

　　注意：在生成XML文件的时候同样应该注意编码问题，除了XML文件编码和XML指定编码应当一致以外，在连接数据库的时候还应该注意XML指定的编码应该和数据库的编

　　3.XML文件的修改和删除

<span> 1</span> <span>$doc</span>= <span>new</span><span> DOMDocument();
</span><span> 2</span> <span>$doc</span>->load("test.xml"<span>);
</span><span> 3</span> 
<span> 4</span> <span>//</span>
<span> 5</span> <span>$students</span> = <span>$doc</span>->getElementsByTagName("student"<span>);
</span><span> 6</span> 
<span> 7</span> <span>//</span><span>遍历$students，将每个student的信息存为$student</span>
<span> 8</span> <span>foreach</span>(<span>$students</span> <span>as</span> <span>$student</span><span>){
</span><span> 9</span>     <span>//</span><span>通过getAttribute获取指定属性的值
</span><span>10</span> 
<span>11</span>     <span>if</span>(<span>$student</span>->getAttribute("id")==2<span>){
</span><span>12</span>         <span>$content</span> = <span>$doc</span>->getElementsByTagName("name")->item(0)->nodeValue = "Kenticny"<span>;
</span><span>13</span> <span>    }
</span><span>14</span>     <span>//</span>
<span>15</span>     <span>if</span>(<span>$student</span>->getAttribute("id")==1<span>){
</span><span>16</span>         <span>//</span><span>17</span> 
<span>18</span>         <span>$student</span>->parentNode->removeChild(<span>$student</span><span>);
</span><span>19</span> <span>    }
</span><span>20</span> 
<span>21</span> <span>}
</span><span>22</span> <span>//</span><span>保存修改的XML文件    </span>
<span>23</span> <span>$doc</span>->save("test.xml");

　　操作。