如何使用 simplehtmldom 从该页面中提取数据

Question

我正在尝试使用 simplehtmldom 从https://benthamopen.com/browse-by-title/B/1/ 提取信息。

具体来说，我想访问页面中显示的部分：

<div style="padding:10px;">
<strong>ISSN: </strong>1874-1207<br><div class="sharethis-inline-share-buttons" style="padding-top:10px;" data-url="https://benthamopen.com/TOBEJ/home/" data-title="The Open Biomedical Engineering Journal"></div>
</div>

我有这个代码：

$html = file_get_html('https://benthamopen.com/browse-by-title/B/1/');

foreach($html->find('div[style=padding:10px;]') as $ele) {
    echo("<pre>".print_r($ele,true)."</pre>");
}

...返回（我只显示页面中的一项）

simplehtmldom\HtmlNode Object
(
    [nodetype] => HDOM_TYPE_ELEMENT (1)
    [tag] => div
    [attributes] => Array
        (
            [style] => padding:10px;
        )

    [nodes] => Array
        (
            [0] => simplehtmldom\HtmlNode Object
                (
                    [nodetype] => HDOM_TYPE_ELEMENT (1)
                    [tag] => strong
                    [attributes] => none
                    [nodes] => none
                )

            [1] => simplehtmldom\HtmlNode Object
                (
                    [nodetype] => HDOM_TYPE_TEXT (3)
                    [tag] => text
                    [attributes] => none
                    [nodes] => none
                )

            [2] => simplehtmldom\HtmlNode Object
                (
                    [nodetype] => HDOM_TYPE_ELEMENT (1)
                    [tag] => br
                    [attributes] => none
                    [nodes] => none
                )

            [3] => simplehtmldom\HtmlNode Object
                (
                    [nodetype] => HDOM_TYPE_ELEMENT (1)
                    [tag] => div
                    [attributes] => Array
                        (
                            [class] => sharethis-inline-share-buttons
                            [style] => padding-top:10px;
                            [data-url] => https://benthamopen.com/TOBEJ/home/
                            [data-title] => The Open Biomedical Engineering Journal
                        )

                    [nodes] => none
                )

        )

)

我不确定如何从这里开始。我要提取：

• ISSN 文本（未在 echo 语句中显示 - 不确定原因）[上例中的 1874-1207]。它是 [nodes] 的元素零
• 'data-url' [https://benthamopen.com/TOBEJ/home/，在上面的例子中]
• “数据标题”[上例中的开放生物医学工程期刊]

可能是我对PHP对象和数组的理解没有达到应有的水平，不知道为什么回显语句中没有显示ISSN。

我尝试了各种（很多）东西，但只是在努力从元素中提取数据。

Answer 1

我不熟悉 simplehtmldom，除了知道避免它。所以我将介绍一个使用 PHP 内置 DOM 类的解决方案：

<?php
libxml_use_internal_errors(true);
// get the HTML
$html = file_get_contents("https://benthamopen.com/browse-by-title/B/1/");

// create a DOM object and load it up
$dom = new DomDocument();
$dom->loadHtml($html);

// create an XPath object and query it
$xpath = new DomXPath($dom);
$elements = $xpath->query("//div[@style='padding:10px;']");

// loop through the matches
foreach ($elements as $el) {
    // skip elements without ISSN
    $text = trim($el->textContent);
    if (strpos($text, "ISSN") !== 0) {
        continue;
    }
    // get the first div inside this thing
    $div = $el->getElementsByTagName("div")[0];
    // dump it out
    printf("%s %s %s<br/>\n", str_replace("ISSN: ", "", $text), $div->getAttribute("data-title"), $div->getAttribute("data-url"));
}

XPath 的东西可能有点让人不知所措，但对于像这样的简单搜索，它与 CSS 选择器并没有太大区别。希望cmets解释一切，如果没有，请告诉我！

输出：

1874-1207 The Open Biomedical Engineering Journal https://benthamopen.com/TOBEJ/home/<br/>
1874-1967 The Open Biology Journal https://benthamopen.com/TOBIOJ/home/<br/>
1874-091X The Open Biochemistry Journal https://benthamopen.com/TOBIOCJ/home/<br/>
1875-0362 The Open Bioinformatics Journal https://benthamopen.com/TOBIOIJ/home/<br/>
1875-3183 The Open Biomarkers Journal https://benthamopen.com/TOBIOMJ/home/<br/>
2665-9956 The Open Biomaterials Science Journal https://benthamopen.com/TOBMSJ/home/<br/>
1874-0707 The Open Biotechnology Journal https://benthamopen.com/TOBIOTJ/home/<br/>