This is the documentation for the unsupported version 2.0. Please consider upgrading your code to the latest stable version
Disallowed Raw HTML Extension
(Note: this extension is included by default within the GFM extension)
The DisallowedRawHtmlExtension automatically escapes certain HTML tags when rendering raw HTML, such as:
<title><textarea><style><xmp><iframe><noembed><noframes><script><plaintext>
Filtering is done by replacing the leading < with the entity <.
This is required by the GFM spec because these particular tags could cause undesirable side-effects if a malicious user tries to introduce them.
All other HTML tags are left untouched by this extension.
Installation
This extension is bundled with league/commonmark. This library can be installed via Composer:
composer require league/commonmark
See the installation section for more details.
Usage
Configure your Environment as usual and simply add the DisallowedRawHtmlExtension provided by this package:
use League\CommonMark\Environment\Environment;
use League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension;
use League\CommonMark\Extension\DisallowedRawHtml\DisallowedRawHtmlExtension;
use League\CommonMark\MarkdownConverter;
// Customize the extension's configuration if needed
// Default values are shown below - you can omit this configuration if you're happy with those defaults
// and don't want to customize them
$config = [
'disallowed_raw_html' => [
'disallowed_tags' => ['title', 'textarea', 'style', 'xmp', 'iframe', 'noembed', 'noframes', 'script', 'plaintext'],
],
];
// Configure the Environment with all the CommonMark parsers/renderers
$environment = new Environment($config);
$environment->addExtension(new CommonMarkCoreExtension());
// Add this extension
$environment->addExtension(new DisallowedRawHtmlExtension());
// Instantiate the converter engine and start converting some Markdown!
$converter = new MarkdownConverter($environment);
echo $converter->convertToHtml('I cannot change the page <title>anymore</title>');
Configuration
This extension can be configured by providing a disallowed_raw_html array with the following nested configuration options. The defaults are shown in the code example above.
disallowed_tags
An array containing a list of tags that should be escaped.