Search and Replace Words in HTML

Question

what I\'m trying to do is make a \'jargon buster\'. Basically I have some html and some glossary terms in a database. When the person clicks on jargon buster it replaces the wor

Answer 1

Assuming all your glossary "words" consist of standard "word" characters, (i.e. [A-Za-z0-9_]), then a simple word boundary assertion can be placed before and after the word in the regex pattern. Try replacing the pertinant statement with this:

$element->innertext = preg_replace(
    '/\b'. $glossary_word .'\b/i',
    ''. $glossary['word'] .'',
    $element->innertext);

This assumes that $glossary_word has been run trough preg_quote (which your code does).

However, if the glossary words may contain other non-standard word characters (such as a '-' dash), a more complex regex can be formulated which incorporates lookahead and lookbehind to ensure that only whole words are matched. For example:

$re_pattern = "/         # Match a glossary whole word.
    (?<=[\s'\"]|^)       # Word preceded by whitespace, quote or BOS.
    {$glossary_word}     # Word to be matched.
    (?=[\s'\".?!,;:]|$)  # Word followed by ws, quote, punct or EOS.
    /ix";