PHP - HTML Purifier - hello w<o>rld/world tutorial striptags

Question

I am just looking into using HTML Purifier to ensure that a user-inputed string (that represents the name of a person) is sanitized.

I do not want to allow any html tags, script, markup etc - I just want the alpha, numeric and normal punctuation characters.

The sheer number of options available for HTML Purifier is daunting and, as far as i can see, the docs do not seem to have a beggining/middle or end

see: http://htmlpurifier.org/docs

Is there a simple hello world tutorial online for HTML Purifier that shows how to sanitize a string removing all the bad stuff out of it.

I am also considering just using strip tags:

• http://php.net/manual/en/function.strip-tags.php

or PHP's in built data sanitizing

• http://us.php.net/manual/en/book.filter.php

Answer 1

I've been using HTMLPurifier for sanitizing the output of a rich text editor, and ended up with:

include_once('htmlpurifier/library/HTMLPurifier.auto.php');

$config = HTMLPurifier_Config::createDefault();
$config->set('Core', 'Encoding', 'UTF-8');
$config->set('HTML', 'Doctype', 'HTML 4.01 Transitional');

if (defined('PURIFIER_CACHE')) {
    $config->set('Cache', 'SerializerPath', PURIFIER_CACHE);
} else {
    # Disable the cache entirely
    $config->set('Cache', 'DefinitionImpl', null);
}

# Help out the Purifier a bit, until it develops this functionality
while (($cleaner = preg_replace('!<(em|strong)>(\s*)</\1>!', '$2', $input)) != $input) {
    $input = $cleaner;
}

$filter = new HTMLPurifier($config);
$output = $filter->purify($input);

The main points of interest:

1. Include the autoloader.
2. Create an instance of HTMLPurifier_Config as $config.
3. Set configuration settings as needed, with $config->set().
4. Create an instance of HTMLPurifier, passing $config to it.
5. Use $filter->purify() on your input.

However, it's entirely overkill for something that doesn't need to allow any HTML in the output.