PHP xml_set_character_data_handler()用法及代码示例

xml_set_character_data_handler()函数是PHP中的内置函数，用于为XML解析器设置字符数据处理函数。

用法:

bool xml_set_character_data_handler( resource $xml_parser, callable $data_handler )

参数：该函数接受上述和以下描述的两个参数：

$xml_parser:它是必填参数。它拥有XML解析器的参考来设置字符数据处理程序。
$data_handler:它是必填参数。它是一个包含函数名称的字符串。
```
handler( resource $parser, string $data )
```
处理函数必须具有以下两个参数：
- $xml_parser:它包含正在调用处理程序的XML解析器的引用。
- $data:它以字符串形式保存字符数据。

返回值：如果成功，则此函数返回True；如果失败，则返回False。

注意：

此函数可用于PHP 4.0.0和更高版本。
这些示例可能不适用于在线IDE。因此，请尝试在本地服务器或php托管服务器上运行它。

gfg.xml文件：

<?xml version="1.0" encoding="utf-8"?> 
<user> 
    <username> user123 </username> 
    <name> firstname lastname </name> 
    <phone> +91-9876543210 </phone> 
    <detail> I am John Doe. Live in Kolkata, India. </detail> 
</user>

程序1:

<?php 
  
// Create an XML parser 
$xml_parser = xml_parser_create(); 
   
// Set the character handler function for XML parser 
xml_set_character_data_handler($xml_parser, "char_print"); 
  
// Opening xml file 
$file_pointer = fopen("gfg.xml", "r"); 
  
// Reading xml data from file 
while($data = fread($file_pointer, 4096)) { 
      
    // Parsing XML data 
    xml_parse($xml_parser, $data, feof($file_pointer)) or
      
    // Display error when parsing error occurs 
    die (sprintf("XML Error: %s at line %d", 
          
        // Error string 
        xml_error_string(xml_get_error_code($xml_parser)), 
          
        // Current line 
        xml_get_current_line_number($xml_parser))); 
} 
  
// Free to xml parser 
xml_parser_free($xml_parser); 
  
fclose($file_pointer); 
   
// Character handler function for XML parser 
function char_print($xml_parser, $data_to_print) { 
    echo $data_to_print; 
} 
   
?>

输出：

user123 
firstname lastname 
+91-9876543210 
I am John Doe. Live in Kolkata, India.

程序2:

<?php 
  
// Create an xml parser 
$xml_parser = xml_parser_create(); 
  
// Element handler function named "starting_handler" 
// enables custom manupulation for output 
function starting_handler($xml_parser, 
            $element_name, $element_attrs) { 
      
    switch($element_name) { 
        case "USER": 
            echo "<u>USER DATA</u><br>"; 
            break; 
        case "USERNAME": 
            echo "Username: "; 
            break; 
        case "NAME": 
            echo "Name: "; 
            break; 
        case "PHONE": 
            echo "Phone no: "; 
            break; 
        case "DETAIL": 
            echo "More about user: "; 
    } 
} 
  
// Element handler function named "ending_handler" 
function ending_handler($xml_parser, $element_name) { 
    echo "<br>"; 
} 
  
// Character handler function named "char_handler" 
function char_handler($xml_parser, $data) { 
    echo $data; 
} 
  
// Setting element handlers 
xml_set_element_handler($xml_parser, 
        "starting_handler", "ending_handler"); 
  
// Setting character data handler 
xml_set_character_data_handler($xml_parser, "char_handler"); 
  
// Opening xml file 
$file_pointer = fopen("gfg.xml", "r"); 
  
// Reading xml file  
while ($data = fread($file_pointer, 4096)) { 
    xml_parse($xml_parser, $data, feof($file_pointer)) or
      
    // Display error while xml parsing 
    die (sprintf("XML Error: %s at line %d", 
      
        // Error string 
        xml_error_string(xml_get_error_code($xml_parser)), 
          
        // Error line number 
        xml_get_current_line_number($xml_parser))); 
} 
  
// Free to xml parser 
xml_parser_free($xml_parser); 
  
// Closing file stream 
fclose($file_pointer); 
  
?>

输出：

USER DATA
Username: user123
Name: firstname lastname
Phone no: +91-9876543210
More about user: I am John Doe. Live in Kolkata, India.

参考： https://www.php.net/manual/en/function.xml-set-character-data-handler.php

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注：本文由纯净天空筛选整理自gekcho大神的英文原创作品 PHP | xml_set_character_data_handler() Function。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。