• PHP全栈学习笔记13

    PHP全栈学习笔记13

    php与ajax技术

    web2.0的到来，ajax逐渐成为主流，什么是ajax，ajax的开发模式，优点，使用技术。（ajax概述，ajax使用的技术，需要注意的 问题，在PHP应用ajax技术的应用）

    什么是ajax，ajax的开发模式，优点。

    ajax是由jesse james garrett创建的，是asynchronous javascript and xml，异步javascript和xml技术，ajax并不是一门新的语言或技术，它是javascript，xml，css，dom等多种技术的组合，可以实现客户端的异步请求操作，可以在不刷新页面下与服务器进行通信，从而减少了用户的等待时间。

    ajax开发模式：
    浏览器（客户端） http传输，http请求， web服务器 数据存储，后端处理，继承系统，服务器端。

    客户端（浏览器）JavaScript调用，ajax引擎 http请求，http传输， web和xml服务器，数据存储，后端处理，继承系统（服务端）。

    优点：减轻服务器的负担，可以把部分由服务器负担的工作转移到客户端上，无刷新更新页面，可以调用xml等外部数据，基于标准化的并被广泛支持的技术。

    JavaScript是一种在web页面中添加动态脚本代码的解释性程序语言。

    xmlhttprequest

    ie浏览器把xmlhttp

    var http_request = new ActiveXObject("Msxml2.XMLHTTP");

    var http_request = new ActiveXObject("Microsoft.XMLHTTP");

    mozailla,safari等其他浏览器

    var http_request = new XMLHttpRequest();

    if(window.XMLHttpRequest){
http_request = new XMLHttpRequest();
}else if(window.ActiveXObject){
 try{
 http_request = new ActiveXObject("Msxml2.XMLHTTP");
 }catch(e){
 try{
 http_request = new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
 try{
 http_request = new ActiveXObject("Microsoft.XMLHTTP");
}catch(e){}
}
}

    XMLHttpRequest对象的常用方法：

    open()方法用于设置进行异步请求目标的url

    open("method", "url" [,asyncFlag [,"userName" [, "password"]]])

    send()方法用于向服务器发送请求

    send(content)

    setRequestHeader()方法

    setRequestHeader()方法为请求的http头设置值

    setRequestHeader("label","value")

    label用于指定http头，value用于指定http头设置值

    open()方法过后才能使用setRequestHeader()方法

    abort()方法
    abort()方法用于停止当前异步请求

    getAllResponseHeaders()方法
    getAllResponseHeaders()方法用于以字符串形式完整的http头信息。

    xmlhttpRequest对象常用的属性
    onreadystatechange 每个状态改变时都会触发这个事件处理器，通常会调用一个JavaScript函数。

    readyState 请求的状态：

    0 为未初始化
1 为正在下载
2 为已加载
3 在交互中
4 为完成

    responseText 服务器的响应，表示字符串

    responseXML 服务器的响应，表示xml

    status 返回服务器的http状态码
    statusText 返回http状态码对应的文本

    xml语言为可扩展的标记语言，提供了用于描述结构化数据的格式。xmlHttpRequest对象与服务器交换的数据，通常采用xml格式。

    dom为文档对象模型，为xml文档的解析定义了一组接口。

    在PHP中应用AJAX技术检测用户名

    <script language="javascript">
var http_request = false;
function createRequest(url) {
	//初始化对象并发出XMLHttpRequest请求
	http_request = false;
	if (window.XMLHttpRequest) { 										//Mozilla等其他浏览器
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			http_request.overrideMimeType("text/xml");
		}
	} else if (window.ActiveXObject) { 								//IE浏览器
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
		   } catch (e) {}
		}
	}
	if (!http_request) {
		alert("不能创建XMLHTTP实例!");
		return false;
	}
	http_request.onreadystatechange = alertContents;   					 //指定响应方法
	
	http_request.open("GET", url, true);								 //发出HTTP请求
	http_request.send(null);
}
function alertContents() {   											 //处理服务器返回的信息
	if (http_request.readyState == 4) {
		if (http_request.status == 200) {
			alert(http_request.responseText);
		} else {
			alert('您请求的页面发现错误');
		}
	}
}
</script>
<script language="javascript">
function checkName() {
	var username = form1.username.value;
	if(username=="") {
		window.alert("请填写用户名!");
		form1.username.focus();
		return false;
	}
	else {
		createRequest('checkname.php?username='+username+'&nocache='+new Date().getTime());
	}
}
</script>

    <?php
	header('Content-type: text/html;charset=GB2312');		//指定发送数据的编码格式为GB2312
	$link=mysql_connect("localhost","root","root");
	mysql_select_db("db_database",$link);
	$GB2312string=iconv( 'UTF-8', 'gb2312//IGNORE' , $RequestAjaxString);			//Ajax中先用encodeURIComponent对要提交的中文进行编码
	mysql_query("set names gb2312");
	$username=$_GET[username];
	$sql=mysql_query("select * from tb_user where name='".$username."'");
	$info=mysql_fetch_array($sql);
	if ($info){
		echo "很报歉!用户名[".$username."]已经被注册!";
	}else{
		echo "祝贺您!用户名[".$username."]没有被注册!";
	}
?>

    类别添加

    <script language="javascript">
var http_request = false;
function createRequest(url) {
	//初始化对象并发出XMLHttpRequest请求
	http_request = false;
	if (window.XMLHttpRequest) { 										//Mozilla等其他浏览器
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			http_request.overrideMimeType("text/xml");
		}
	} else if (window.ActiveXObject) { 								//IE浏览器
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
		   } catch (e) {}
		}
	}
	if (!http_request) {
		alert("不能创建XMLHTTP实例!");
		return false;
	}
	http_request.onreadystatechange = alertContents;   					 //指定响应方法
	
	http_request.open("GET", url, true);								 //发出HTTP请求
	http_request.send(null);
}
function alertContents() {   											 //处理服务器返回的信息
	if (http_request.readyState == 4) {
		if (http_request.status == 200) {
			sort_id.innerHTML=http_request.responseText;				//设置sort_id HTML文本替换的元素内容
		} else {
			alert('您请求的页面发现错误');
		}
	}
}
</script>
<script language="javascript">
function checksort() {
	var txt_sort = form1.txt_sort.value;
	if(txt_sort=="") {
		window.alert("请填写文章类别!");
		form1.txt_sort.focus();
		return false;
	}
	else {
		createRequest('checksort.php?txt_sort='+txt_sort);
	}
}
</script>

    <?php
	$link=mysql_connect("localhost","root","root");
	mysql_select_db("db_database",$link);
	$GB2312string=iconv( 'UTF-8', 'gb2312//IGNORE',$RequestAjaxString);			//Ajax中先用encodeURIComponent对要提交的中文进行编码
	mysql_query("set names gb2312");
	$sort=$_GET[txt_sort];
	mysql_query("insert into tb_sort(sort) values('$sort')");
	header('Content-type: text/html;charset=GB2312');		//指定发送数据的编码格式为GB2312
?>
<table border="0" cellpadding="0" cellspacing="0">
  <tr>
	<td>
	<select name="select" >
	<?php
		$link=mysql_connect("localhost","root","root");
		mysql_select_db("db_database23",$link);
		$GB2312string=iconv( 'UTF-8', 'gb2312//IGNORE' , $RequestAjaxString);			//Ajax中先用encodeURIComponent对要提交的中文进行编码
		mysql_query("set names gb2312");
		$sql=mysql_query("select distinct * from tb_sort group by sort");
		$result=mysql_fetch_object($sql);
		do{
			header('Content-type: text/html;charset=GB2312');		//指定发送数据的编码格式为GB2312
	?>
  	<option value="<?php echo $result->sort;?>" selected><?php echo $result->sort;?></option>
	<?php
		}while($result=mysql_fetch_object($sql));
	?>
    </select>

    xml基础技术

    了解xml，使用simpleXML解析文档的方法
    遍历xml文档，修改，保存xml，创建xml文档的方法

    xml语法
    xml文档结构，xml声明，处理指令，注解，xml元素，xml属性，使用cdata标记，xml命令空间。

    XML文档结构

    <?xml version="1.0" encoding="gb2312" standalone="yes"?>

    <?xml-stylesheet type="text/css" href="111.css"?>

    XML声明

    <?xml version="1.0" encoding="gb2312" standalone="yes"?>

    image.png

    处理指令

    <?xml-stylesheet type = "text/css" href="111.css"?>

    <?处理指令名 处理执行信息?>

    xml-stylesheet：样式表单处理指令
    type="text/css"：设定了文档所使用的样式是css
    href="111.css"：设定了样式文件的地址

    image.png

    XML属性

    <标签 属性名="属性值" 属性名=""…>内容</标签＞

    image.png

    SimpleXML
    创建SimpleXML对象
    Simplexml_load_file()函数，将指定的文件解析到内存中
    Simplexml_load_string()函数，将创建的字符串解析到内存当中
    Simplexml_load_date()函数，将一个使用dom函数创建的domDocument对象导入到内存当中

    遍历所有子元素
    children()方法和foreach循环语句可以遍历所有子节点元素

    遍历所有属性
    SimpleXML对象中的attributes()方法

    <?xml version="1.0" encoding="GB2312"?>
<exam>

</exam>

    <?php
header('Content-Type:text/html;charset=utf-8');
?>

<?php
/*  第一种方法  */
$xml_1 = simplexml_load_file("5.xml");
print_r($xml_1);
/*  第二种方法  */
$str = <<<XML
<?xml version='1.0' encoding='gb2312'?>
<Object>
	<ComputerBook>
		<title>PHP</title>
	</ComputerBook>
</Object>
XML;
$xml_2 = simplexml_load_string($str);
echo '<br>';
print_r($xml_2);
/*  第三种方法  */
$dom = new domDocument();
$dom -> loadXML($str);
$xml_3 = simplexml_import_dom($dom);
echo '<br>';
print_r($xml_3);
?>

    <?php
header('Content-Type:text/html;charset=utf-8');
?>
<style type="text/css">

<?php
$str = <<<XML
<?xml version='1.0' encoding='gb2312'?>
<object>
	<book>
		<computerbook>PHP</computerbook>
	</book>
	<book>
		<computerbook>PHP</computerbook>
	</book>
</object>
XML;
$xml = simplexml_load_string($str);
foreach($xml->children() as $layer_one){
	print_r($layer_one);
	echo '<br>';
	foreach($layer_one->children() as $layer_two){
		print_r($layer_two);
		echo '<br>';
	}
}
?>

    
<?php
$str = <<<XML
<?xml version='1.0' encoding='gb2312'?>
<object name='commodity'>
	<book type='computerbook'>
		<bookname name='22'/>
	</book>
	<book type='historybook'>
		<booknanme name='111'/>
	</book>
</object>
XML;
$xml = simplexml_load_string($str);
foreach($xml->children() as $layer_one){
	foreach($layer_one->attributes() as $name => $vl){
		echo $name.'::'.$vl;
	}
	echo '<br>';
	foreach($layer_one->children() as $layer_two){
		foreach($layer_two->attributes() as $nm => $vl){
			echo $nm."::".$vl;
		}
		echo '<br>';
	}
}
?>

    <?php
	header('Content-Type:text/html;charset=utf-8');
?>

<?php
$str = <<<XML
<?xml version='1.0' encoding='gb2312'?>
<object name='商品'>
	<book>
		<computerbook>P123</computerbook>
	</book>
	<book>
		<computerbook name='456'/>
	</book>
</object>
XML;
$xml = simplexml_load_string($str);
echo $xml[name].'<br>';
echo $xml->book[0]->computerbook.'<br>';
echo $xml->book[1]->computerbook['name'].'<br>';
?>

    <?php
header('Content-Type:text/html;charset=utf-8');
$str=<<<XML
<?xml version='1.0' encoding='gb2312'?>
<object name='商品'>
	<book>
		<computerbook type='12356'>123</computerbook>
	</book>
</object>
XML;

$xml = simplexml_load_string($str);
echo $xml[name].'<br />';
$xml->book->computerbook['type'] = iconv('gb2312','utf-8','PHP123');
$xml->book->computerbook = iconv('gb2312','utf-8','PHP456');
echo $xml->book->computerbook['type'].' => ';
echo $xml->book->computerbook;
?>

    <?php
$xml = simplexml_load_file('10.xml');
$xml->book->computerbook['type'] = iconv('gb2312','utf-8','PHP1');
$xml->book->computerbook = iconv('gb2312','utf-8','PHP2');
$modi = $xml->asXML();
file_put_contents('10.xml',$modi);
$str = file_get_contents('10.xml');
echo $str;
?>

    <?php
	//Message_XML类，继承PHP5的DomDocument类
	class Message_XML extends DomDocument{
	//属性
	private $Root;
	//方法
	//构造函数
	public function __construct() {
		parent:: __construct();
	//创建或读取存储留言信息的XML文档message.xml
	if (!file_exists("message.xml")){
		$xmlstr = "<?xml version='1.0' encoding='GB2312'?><message></message>";
		$this->loadXML($xmlstr);
		$this->save("message.xml");
	}
	else
		$this->load("message.xml");
}
public function add_message($user,$address){  //添加数据
	$Root = $this->documentElement;
	//获取留言消息
	$admin_id =date("Ynjhis");
	$Node_admin_id= $this->createElement("admin_id");
	$text= $this->createTextNode(iconv("GB2312","UTF-8",$admin_id));
	$Node_admin_id->appendChild($text);
	
	$Node_user = $this->createElement("user");
	$text  = $this->createTextNode(iconv("GB2312","UTF-8",$user));
	$Node_user->appendChild($text);
	
	$Node_address = $this->createElement("address");
	$text= $this->createTextNode(iconv("GB2312","UTF-8",$address));
	$Node_address->appendChild($text);

	$Node_Record = $this->createElement("record");
	$Node_Record->appendChild($Node_admin_id);
	$Node_Record->appendChild($Node_user);
	$Node_Record->appendChild($Node_address);
	//加入到根结点下
	$Root->appendChild($Node_Record);
	$this->save("message.xml");  
	echo "<script>alert('添加成功');location.href='".$_SERVER['PHP_SELF']."'</script>";
}
public function delete_message($admin_id){ 	//删除数据
	$Root = $this->documentElement;
	$xpath = new DOMXPath($this);
	$Node_Record= $xpath->query("//record[admin_id='$admin_id']");
	$Root->removeChild($Node_Record->item(0));
	$this->save("message.xml");
	echo "<script>alert('删除成功');location.href='".$_SERVER['PHP_SELF']."'</script>";
}

public function show_message(){  //读取数据
    $root=$this-documentElement;
	$xpath=new DOMXPath($this);
	
	$Node_Record=$this->getElementsByTagName("record");
	$Node_Record_length=$Node_Record->length;
	print"<table width='506' bgcolor='#FFFFCC'><tr>";
    print"<td width='106' height='22' align='center'>";
	print"<b>用户名</b>";
	print"</td><td width='400' align='center'>";
	print"<b>留言信息</b></td></tr>";

	for($i=0;$i<$Node_Record->length;$i++){
	    $k=0;
		foreach($Node_Record->item($i)->childNodes as $articles){
		   $field[$k]=iconv("UTF-8","GB2312",$articles->textContent);
			$k++;
	}
	print"<table width='506' bgcolor='#FFFFCC'><tr>";
	print"<td width='100' height='22' align='center'>";
	print"$field[1]";
	print"</td><td width='300' align='left'>";
	print"$field[2]";
	print"</td><td width='100' align='center'>";
	print"<a href='?Action=delete_message&admin_id=$field[0]'>删除</a></td>";
	print"</tr></table>"; 
	}}
	public function post_message(){
		print "<table width='506' bgcolor='#FFFFCC'><form method='post' action='?Action=add_message'>";
		print "<tr><td  width='106'height='22'>&nbsp;&nbsp;&nbsp;&nbsp;用户名：</td><td><input type=text name='user' size=50></td></tr>";
		print "<tr><td width='106' height='22'>&nbsp;&nbsp;&nbsp;&nbsp;留言信息：</td><td width='400'><textarea name='address' cols='48' rows='5' id='address'></textarea></td></tr>";
		print "<tr><td width='106' height='30'>&nbsp;&nbsp;<input type='submit' value='添加数据'></td><td align='right'><a href=?Action=show_message>查看数据</a>&nbsp;&nbsp;&nbsp;&nbsp;</td></tr></form></table>";
	}

}
?>

<html>                                                                                                                           
	<head>                                                                                                                  
	<title>定义一个PHP读取XML类</title>                                                                                        
		<style>
		td,body{font-size:12px}
		a:link {
	text-decoration: none;
}
a:visited {
	text-decoration: none;
}
a:hover {
	text-decoration: none;
}
a:active {
	text-decoration: none;
}
</style>                                                                                      
	<meta http-equiv="Content-Type" content="text/html; charset=gb2312"></head>                                                                                                                        
<body>                                                                                                                         
<table width=506 height=50 border=0 cellpadding=0 cellspacing=0 bgcolor="#33BE6B">                                
                                                                                                                          
		<tr>                                                                                                                         
		  <td width="506" height=50 valign="bottom" background="title.gif"><table width="506">
            <tr>
              <td height="24" align="right" scope="col">&nbsp;&nbsp;<a href=?Action=post_message>添加数据</a>&nbsp;&nbsp;&nbsp;</td>
            </tr>
          </table></td>
		</tr>  
		<?php                                                                                       
		$HawkXML = new Message_XML;     
		$Action ="";      
		if(isset($_GET['Action']))     
			  $Action = $_GET['Action'];                                                                                       
	  	switch($Action){                                                                                            
			case "show_message":	    //查看                                                                               
				$HawkXML->show_message();                                                                         
				break;                                                                                                     
			case "post_message":        //提交                                                                               
				$HawkXML->post_message();                                                                       
				break;                                                                                                      
			case "add_message":          //添加                                                                            
				$HawkXML->add_message($_POST['user'],$_POST['address']);                                             
				break;	  
			case "delete_message":		//删除
				$HawkXML->delete_message($_GET['admin_id']);
				break;
		}                                                                                                
	   ?>	
</table>                                                                                                                   
</body>                                                                                                                      
</html>                                                                                                                        

    <?php
	//Message_XML类，继承PHP5的DomDocument类
	class Message_XML extends DomDocument{
	//属性
	private $Root;
	//方法
	//构造函数
	public function __construct() {
		parent:: __construct();
	//创建或读取存储留言信息的XML文档message.xml
	if (!file_exists("message.xml")){
		$xmlstr = "<?xml version='1.0' encoding='GB2312'?><message></message>";
		$this->loadXML($xmlstr);
		$this->save("message.xml");
	}
	else
		$this->load("message.xml");
}
public function add_message($user,$address){  //添加数据
	$Root = $this->documentElement;
	//获取留言消息
	$admin_id =date("Ynjhis");
	$Node_admin_id= $this->createElement("admin_id");
	$text= $this->createTextNode(iconv("GB2312","UTF-8",$admin_id));
	$Node_admin_id->appendChild($text);
	
	$Node_user = $this->createElement("user");
	$text  = $this->createTextNode(iconv("GB2312","UTF-8",$user));
	$Node_user->appendChild($text);
	
	$Node_address = $this->createElement("address");
	$text= $this->createTextNode(iconv("GB2312","UTF-8",$address));
	$Node_address->appendChild($text);

	$Node_Record = $this->createElement("record");
	$Node_Record->appendChild($Node_admin_id);
	$Node_Record->appendChild($Node_user);
	$Node_Record->appendChild($Node_address);
	//加入到根结点下
	$Root->appendChild($Node_Record);
	$this->save("message.xml");  
	echo "<script>alert('添加成功');location.href='".$_SERVER['PHP_SELF']."'</script>";
}

public function show_message(){  //读取数据
    $root=$this-documentElement;
	$xpath=new DOMXPath($this);
	
	$Node_Record=$this->getElementsByTagName("record");
	$Node_Record_length=$Node_Record->length;
	print"<table width='506' bgcolor='#FFFFCC'><tr>";
    print"<td width='106' height='22' align='center'>";
	print"<b>用户名</b>";
	print"</td><td width='400' align='center'>";
	print"<b>留言信息</b></td></tr>";

	for($i=0;$i<$Node_Record->length;$i++){
	    $k=0;
		foreach($Node_Record->item($i)->childNodes as $articles){
		   $field[$k]=iconv("UTF-8","GB2312",$articles->textContent);
			$k++;
	}
	print"<table width='506' bgcolor='#FFFFCC'><tr>";
	print"<td width='100' height='22' align='center'>";
	print"$field[1]";
	print"</td><td width='400' align='left'>";
	print"$field[2]";
	print"</td>";
	print"</tr></table>"; 
	}}
	public function post_message(){
		print "<table width='506' bgcolor='#FFFFCC'><form method='post' action='?Action=add_message'>";
		print "<tr><td  width='106'height='22'>&nbsp;&nbsp;&nbsp;&nbsp;用户名：</td><td><input type=text name='user' size=50></td></tr>";
		print "<tr><td width='106' height='22'>&nbsp;&nbsp;&nbsp;&nbsp;留言信息：</td><td width='400'><textarea name='address' cols='48' rows='5' id='address'></textarea></td></tr>";
		print "<tr><td width='106' height='30'>&nbsp;&nbsp;<input type='submit' value='添加数据'></td><td align='right'><a href=?Action=show_message>查看数据</a>&nbsp;&nbsp;&nbsp;&nbsp;</td></tr></form></table>";
	}

}
?>
<html>                                                                                                                           
	<head>
	<title>使用XML来存储少量的数据</title>                                                                                 
	<style>
	td,body{font-size:12px}
	a:link {
	text-decoration: none;
}
a:visited {
	text-decoration: none;
}
a:hover {
	text-decoration: none;
}
a:active {
	text-decoration: none;
}
</style>                                                                                      
	<meta http-equiv="Content-Type" content="text/html; charset=gb2312"></head>                                                                                                                        
<body>                                                                                                                         
<table width=506 height=50 border=0 cellpadding=0 cellspacing=0 bgcolor="#33BE6B">                                
                                                                                                                          
		<tr>                                                                                                                         
		  <td width="506" height=50 valign="bottom" background="title.gif"><table width="506">
            <tr>
              <td height="24" align="right" scope="col">&nbsp;&nbsp;<a href=?Action=post_message>添加数据</a>&nbsp;&nbsp;&nbsp;</td>
            </tr>
          </table></td>
		</tr>  
		<?php                                                                                       
		$HawkXML = new Message_XML;     
		$Action ="";      
		if(isset($_GET['Action']))     
			  $Action = $_GET['Action'];                                                                                       
	  	switch($Action){                                                                                            
			case "show_message":	    //查看                                                                               
				$HawkXML->show_message();                                                                         
				break;                                                                                                     
			case "post_message":        //提交                                                                               
				$HawkXML->post_message();                                                                       
				break;                                                                                                      
			case "add_message":          //添加                                                                            
				$HawkXML->add_message($_POST['user'],$_POST['address']);                                             
				break;	  }                                                                                                
	     ?>
</table>                                                                                                                   
</body>                                                                                                                      
</html>

    结言

    好了，欢迎在留言区留言，与大家分享你的经验和心得。

    感谢你学习今天的内容，如果你觉得这篇文章对你有帮助的话，也欢迎把它分享给更多的朋友，感谢。

    感谢！承蒙关照！您真诚的赞赏是我前进的最大动力！

    image

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  • 原文地址：https://www.cnblogs.com/dashucoding/p/10784586.html
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