PHP: Simple HTML DOM Parser - how to get the element which has certain content?

问题

In PHP I'm using the Simple HTML DOM Parser class.

I have a HTML file which has multiple A-tags.

Now I need to find the tag that has a certain text inside.

for example :

$html = "<a id='tag1'>A</a>
         <a id='tag2'>B</a>
         <a id='tag3'>C</a>
        ";

$dom = str_get_html($html);
$tag = $dom->find("a[plaintext=B]");

The above example doesn't work, since plaintext can only be used as an attribute.

Any idea's?

回答1:

<?php
include("simple_html_dom.php");
$html = "<a id='tag1'>A</a>
         <a id='tag2'>B</a>
         <a id='tag3'>C</a>
        ";

$dom = str_get_html($html);
$select = NULL;
foreach($dom->find('a') as $element) {
       if ($element->innertext === "B") {
            $select = $element;
            break;   
       }
}
?>

回答2:

Assuming each specific text you are looking for maps only to a single link (which sounds like you do), you can build an associative lookup array. I just encountered this need myself. Here is how I handled it. This way you don't need to loop thru all the links every time.

function populateOutlines($htmlOutlines)
{
  $marker = "courses";
  $charSlashFwd = "/";

  $outlines = array();

  foreach ($htmlOutlines->find("a") as $element)
  {
    // filter links for ones with certain markers if required
    if (strpos($element->href, $marker) !== false)
    {
      // construct the key the way you need it
      $dir = explode($charSlashFwd, $element->href);
      $code = preg_replace(
        "/[^a-zA-Z0-9 ]/", "", strtoupper(
          $dir[1]." ".$dir[2]));

      // insert the lookup entry
      $outlines[$code] = $element->href;
    }
  }

  return $outlines;
}

// ...stuff...

$htmlOutlines = file_get_html($urlOutlines);
$outlines = populateOutlines($htmlOutlines);

// ...more stuff...

if (array_key_exists($code, $outlines)) {
  $outline = $outlines[$code];
} else {
  $outline = "n/a";
}

来源：https://stackoverflow.com/questions/11060170/php-simple-html-dom-parser-how-to-get-the-element-which-has-certain-content

标签

php

web-scraping

simple-html-dom