Question

I am being “thick this morning” so please excuse this simple question – I have an array of keywords e.g. array('keyword1','keyword2'....) and I have a string of text – (bit like a blog content in length i.e. not just a few words but may be 200-800 words) what is the best way to search the string for the keywords and replace them with an href link. So in the text ‘keyword 1’ (as plain text) will become <a href='apage'>keyword1</a> and so on.

See said was being thick this am.

Thanks in adavance.

Answer 1

Typical preg_replace case:

$text = "There is some text keyword1 and lorem ipsum keyword2.";
$keywords = array('keyword1', 'keyword2');

$regex = '/('.implode('|', $keywords).')/i';

// You might want to make the replacement string more dependent on the
// keyword matched, but you 'll have to tell us more about it
$output = preg_replace($regex, '<a href="apage">\\1</a>', $text);

print_r($output);

See it in action.

Now the above doesn’t do a very “smart” replace in the sense that the href is not a function of the matched keyword, while in practice you will probably want to do that. Look into preg_replace_callback for more flexibility here, or edit the question and provide more information regarding your goal.