$domxpath->query - 检查标题

Question

下面的查询仅搜索网站页面上 <h2> 标记后的第一段 "History"

            $paragraph = $domxpath->query('
                //h2[*[
                        contains(text(), "History")
                      ]
                    ]
                /following-sibling::p[
                        position() = 1 
                    ]'
            );

但我想以某种方式检查是否有任何包含历史记录的 <h2> 标签

foreach($paragraph as $node) {
                    $content= $node->nodeValue;                 
                }



                if(!isset($content)){
                    echo $content;
                }else{
                    echo "static content";
                }

这样不行

更新

$html = file_get_contents( 'www.site.com' );    
                $document = new DOMDocument();              
                $document->loadHTML(mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'));
                $domxpath = new DOMXPath($document);
                $paragraph = $domxpath->query('
                    //h2[*[
                            contains(text(), "History")
                          ]
                        ]
                    /following-sibling::p[
                            position() = 1 
                        ]'
                );
            }   


                foreach($paragraph as $node) {
                    $content= $node->nodeValue;

                }

                if(!isset($content)){
                    echo $content;
                }else{
                    echo "static content";
                }

但我不知道，因为当它没有 "history" 时，它不会打印 "else"

中的静态内容

代码html:

下面div里面有页面的所有主要内容

<div id="mw-content-text" lang="pt" dir="ltr" class="mw-content-ltr">

我想找到 "History"

<h2><span id="Hist.C3.B3ria"></span><span class="mw-headline" id="History">History</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Adamantina&amp;veaction=edit&amp;section=1" class="mw-editsection-visualeditor" title="Editar secção: History">editar</a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Adamantina&amp;action=edit&amp;section=1" title="Editar secção: History">editar código-fonte</a><span class="mw-editsection-bracket">]</span></span></h2>

在开始 <h2> 标签和结束 </h2> 之间有很多代码，可以在上面看到

Answer 1

使用此 XPath 查询获取其中任意位置包含字符串 "History" 的任何 h2 元素：

//h2/*[contains(text(), "History")]

然后，检查结果是否为阳性，统计结果。如果大于0则有结果：

$paragraph = $domxpath->query('//h2/*[contains(text(), "History")]');
if ($paragraph->length > 0) {
    echo "Results!";
}
else {
    echo "Not contained";
}

Demo

$domxpath->query - 检查标题

$domxpath->query - Check for title

php

dom

domparser