xml数据解析（PHP）

以解析Google API 接口提供的天气情况为例，我们取今天的天气及气温。
API地址：http://www.google.com/ig/api?weather=shenzhen

【XML文件内容】

<?xml version="1.0"?>  
<xml_api_reply version="1">  
    <weather module_id="0" tab_id="0" mobile_row="0" mobile_zipped="1" row="0" section="0" >  
        <forecast_information>  
            <city data="Shenzhen, Guangdong"/>  
            <postal_code data="shenzhen"/>  
            <latitude_e6 data=""/>  
            <longitude_e6 data=""/>  
            <forecast_date data="2009-10-05"/>  
            <current_date_time data="2009-10-04 05:02:00 +0000"/>  
            <unit_system data="US"/>  
        </forecast_information>  
        <current_conditions>  
            <condition data="Sunny"/>  
            <temp_f data="88"/>  
            <temp_c data="31"/>  
            <humidity data="Humidity: 49%"/>  
            <icon data="/ig/images/weather/sunny.gif"/>  
            <wind_condition data="Wind:  mph"/>  
        </current_conditions>  
    </weather>  
</xml_api_reply>  

【使用DomDocument解析】

<?PHP
header("Content-type:text/html; Charset=utf-8");
$url = "http://www.google.com/ig/api?weather=shenzhen";
 
//  加载XML内容
$content = file_get_contents($url);
$content = get_utf8_string($content);
$dom = DOMDocument::loadXML($content);
/*
此处也可使用如下所示的代码，
$dom = new DOMDocument();
$dom->load($url);
 */
 
$elements = $dom->getElementsByTagName("current_conditions");
$element = $elements->item(0);
$condition = get_google_xml_data($element, "condition");
$temp_c = get_google_xml_data($element, "temp_c");
echo '天气：', $condition, '<br />';
echo '温度：', $temp_c, '<br />';
 
function get_utf8_string($content) {    //  将一些字符转化成utf8格式
    $encoding = mb_detect_encoding($content, array('ASCII','UTF-8','GB2312','GBK','BIG5'));
    return  mb_convert_encoding($content, 'utf-8', $encoding);
}
 
function get_google_xml_data($element, $tagname) {
    $tags = $element->getElementsByTagName($tagname);   //  取得所有的$tagname
 
    $tag = $tags->item(0);  //  获取第一个以$tagname命名的标签
    if ($tag->hasAttributes()) {    //  获取data属性
        $attribute = $tag->getAttribute("data");
        return $attribute;
    }else {
        return false;
    }
}
?>

【XMLReader】

<?PHP
header("Content-type:text/html; Charset=utf-8");
$url = "http://www.google.com/ig/api?weather=shenzhen";
 
//  加载XML内容
$xml = new XMLReader();
$xml->open($url);
 
$condition = '';
$temp_c = '';
while ($xml->read()) {
//      echo $xml->name, "==>", $xml->depth, "<br>";
      if (!empty($condition) && !empty($temp_c)) {
          break;
      }
      if ($xml->name == 'condition' && empty($condition)) {  //  取第一个condition
            $condition = $xml->getAttribute('data');
      }
 
      if ($xml->name == 'temp_c' && empty($temp_c)) {    //  取第一个temp_c
          $temp_c = $xml->getAttribute('data');
      }
 
      $xml->read();
}
 
$xml->close();
echo '天气：', $condition, '<br />';
echo '温度：', $temp_c, '<br />';

【DOMXPath】

<?PHP
header("Content-type:text/html; Charset=utf-8");
$url = "http://www.google.com/ig/api?weather=shenzhen";
 
//  加载XML内容
$dom = new DOMDocument();
$dom->load($url);
 
$xpath = new DOMXPath($dom);
$element = $xpath->query("/xml_api_reply/weather/current_conditions")->item(0);
$condition = get_google_xml_data($element, "condition");
$temp_c = get_google_xml_data($element, "temp_c");
echo '天气：', $condition, '<br />';
echo '温度：', $temp_c, '<br />';
 
function get_google_xml_data($element, $tagname) {
    $tags = $element->getElementsByTagName($tagname);   //  取得所有的$tagname
 
    $tag = $tags->item(0);  //  获取第一个以$tagname命名的标签
    if ($tag->hasAttributes()) {    //  获取data属性
        $attribute = $tag->getAttribute("data");
        return $attribute;
    }else {
        return false;
    }
}
?>

【xml_parse_into_struct】

<?PHP
header("Content-type:text/html; Charset=utf-8");
$url = "http://www.google.com/ig/api?weather=shenzhen";
 
//  加载XML内容
$content = file_get_contents($url);
$p = xml_parser_create();
xml_parse_into_struct($p, $content, $vals, $index);
xml_parser_free($p);
 
echo '天气：', $vals[$index['CONDITION'][0]]['attributes']['DATA'], '<br />';
echo '温度：', $vals[$index['TEMP_C'][0]]['attributes']['DATA'], '<br />';

【Simplexml】

// Charset: utf-8
/**
  * 用php Simplexml 调用google天气预报api,和g官方的例子不一样
  * google 官方php domxml 获取google天气预报的例子
  * http://www.google.com/tools/toolbar/buttons/intl/zh-CN/apis/howto_guide.html
  *
  * @copyright Copyright (c) 2008 <cmpan(at)qq.com>
  * @license New BSD License
  * @version 2008-11-9
  */
 
// 城市，用城市拼音
$city = empty($_GET['city']) ? 'shenzhen' : $_GET['city'];
$content = file_get_contents("http://www.google.com/ig/api?weather=$city&hl=zh-cn");
$content || die("No such city's data");
$content = mb_convert_encoding($content, 'UTF-8', 'GBK');
$xml = simplexml_load_string($content);
 
$date = $xml->weather->forecast_information->forecast_date->attributes();
$html = $date. "<br>\r\n";
 
$current = $xml->weather->current_conditions;
 
$condition = $current->condition->attributes();
$temp_c = $current->temp_c->attributes();
$humidity = $current->humidity->attributes();
$icon = $current->icon->attributes();
$wind = $current->wind_condition->attributes();
 
$condition && $condition = $xml->weather->forecast_conditions->condition->attributes();
$icon && $icon = $xml->weather->forecast_conditions->icon->attributes();
 
$html.= "当前: {$condition}, {$temp_c}°C,<img src='http://www.google.com/ig{$icon}'/> {$humidity} {$wind} <br />\r\n";
 
foreach($xml->weather->forecast_conditions as $forecast) {
    $low = $forecast->low->attributes();
    $high = $forecast->high->attributes();
    $icon = $forecast->icon->attributes();
    $condition = $forecast->condition->attributes();
    $day_of_week = $forecast->day_of_week->attributes();
    $html.= "{$day_of_week} : {$high} / {$low} °C, {$condition} <img src='http://www.google.com/ig{$icon}' /><br />\r\n";
}
 
header('Content-type: text/html; Charset: utf-8');
print $html;
?>