Articles on this website have previews- the short extracts of every article displayed on the home page.

I demonstrate how these are constructed in PHP.

Starting with an article $markdownBody, I compile it into an HTML string, $html using Parsedown.

Extract the text from inside <p> elements

We don't want headings and blocks of code appearing in previews! The following line filters out only the paragraphs.

preg_match_all('/<p>(.*?)<\/p>/', $html, $matches);

The array $matches contains two arrays.

    0 => array(
        0=> <p>I am first</p>
        1=><p>I am second</p>
        2=><p>I am third</p>

        0=>I am first
        1=>I am second
        2=>I am third

The second array is more helpful. Let's join it into a string.

$matches = $matches[1];
$p_html = implode(" ", $matches);

The paragraphs could contain HTML elements, so let's strip those too.

$p_text = strip_tags($p_html);

Limit the length of the text

PHP's wordwrap function can be used to split a string into roughly equal segments without breaking any words.

$p_text = wordwrap($p_text, 100);
$p_text = explode("\n", $p_text);
$p_text = $str[0] . '...';

Source: https://stackoverflow.com/a/1104329