PHP Markdown ============ PHP Markdown Lib 1.7.0 - 29 Oct 2016 by Michel Fortin based on Markdown by John Gruber Introduction ------------ This is a library package that includes the PHP Markdown parser and its sibling PHP Markdown Extra with additional features. Markdown is a text-to-HTML conversion tool for web writers. Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML). "Markdown" is actually two things: a plain text markup syntax, and a software tool, originally written in Perl, that converts the plain text markup to HTML. PHP Markdown is a port to PHP of the original Markdown program by John Gruber. * [Full documentation of the Markdown syntax]() — Daring Fireball (John Gruber) * [Markdown Extra syntax additions]() — Michel Fortin Requirement ----------- This library package requires PHP 5.3 or later. Note: The older plugin/library hybrid package for PHP Markdown and PHP Markdown Extra is still maintained and will work with PHP 4.0.5 and later. Before PHP 5.3.7, pcre.backtrack_limit defaults to 100 000, which is too small in many situations. You might need to set it to higher values. Later PHP releases defaults to 1 000 000, which is usually fine. Usage ----- This library package is meant to be used with class autoloading. For autoloading to work, your project needs have setup a PSR-0-compatible autoloader. See the included Readme.php file for a minimal autoloader setup. (If you cannot use autoloading, see below.) With class autoloading in place, putting the 'Michelf' folder in your include path should be enough for this to work: use \Michelf\Markdown; $my_html = Markdown::defaultTransform($my_text); Markdown Extra syntax is also available the same way: use \Michelf\MarkdownExtra; $my_html = MarkdownExtra::defaultTransform($my_text); If you wish to use PHP Markdown with another text filter function built to parse HTML, you should filter the text *after* the `transform` function call. This is an example with [PHP SmartyPants][psp]: use \Michelf\Markdown, \Michelf\SmartyPants; $my_html = Markdown::defaultTransform($my_text); $my_html = SmartyPants::defaultTransform($my_html); All these examples are using the static `defaultTransform` static function found inside the parser class. If you want to customize the parser configuration, you can also instantiate it directly and change some configuration variables: use \Michelf\MarkdownExtra; $parser = new MarkdownExtra; $parser->fn_id_prefix = "post22-"; $my_html = $parser->transform($my_text); To learn more, see the full list of [configuration variables]. [configuration variables]: https://michelf.ca/projects/php-markdown/configuration/ ### Usage without an autoloader If you cannot use class autoloading, you can still use `include` or `require` to access the parser. To load the `\Michelf\Markdown` parser, do it this way: require_once 'Michelf/Markdown.inc.php'; Or, if you need the `\Michelf\MarkdownExtra` parser: require_once 'Michelf/MarkdownExtra.inc.php'; While the plain `.php` files depend on autoloading to work correctly, using the `.inc.php` files instead will eagerly load the dependencies that would be loaded on demand if you were using autoloading. Public API and Versioning Policy --------------------------------- Version numbers are of the form *major*.*minor*.*patch*. The public API of PHP Markdown consist of the two parser classes `Markdown` and `MarkdownExtra`, their constructors, the `transform` and `defaultTransform` functions and their configuration variables. The public API is stable for a given major version number. It might get additions when the minor version number increments. **Protected members are not considered public API.** This is unconventional and deserves an explanation. Incrementing the major version number every time the underlying implementation of something changes is going to give nonessential version numbers for the vast majority of people who just use the parser. Protected members are meant to create parser subclasses that behave in different ways. Very few people create parser subclasses. I don't want to discourage it by making everything private, but at the same time I can't guarantee any stable hook between versions if you use protected members. **Syntax changes** will increment the minor number for new features, and the patch number for small corrections. A *new feature* is something that needs a change in the syntax documentation. Note that since PHP Markdown Lib includes two parsers, a syntax change for either of them will increment the minor number. Also note that there is nothing perfectly backward-compatible with the Markdown syntax: all inputs are always valid, so new features always replace something that was previously legal, although generally nonsensical to do. Bugs ---- To file bug reports please send email to: Please include with your report: (1) the example input; (2) the output you expected; (3) the output PHP Markdown actually produced. If you have a problem where Markdown gives you an empty result, first check that the backtrack limit is not too low by running `php --info | grep pcre`. See Installation and Requirement above for details. Development and Testing ----------------------- Pull requests for fixing bugs are welcome. Proposed new features are going to be meticulously reviewed -- taking into account backward compatibility, potential side effects, and future extensibility -- before deciding on acceptance or rejection. If you make a pull request that includes changes to the parser please add tests for what is being changed to [MDTest][] and make a pull request there too. [MDTest]: https://github.com/michelf/mdtest/ Donations --------- If you wish to make a donation that will help me devote more time to PHP Markdown, please visit [michelf.ca/donate] or send Bitcoin to [1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH]. [michelf.ca/donate]: https://michelf.ca/donate/#!Thanks%20for%20PHP%20Markdown [1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH]: bitcoin:1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH Version History --------------- PHP Markdown Lib 1.7.0 (29 Oct 2016) * Added a `hard_wrap` configuration variable to make all newline characters in the text become `
` tags in the HTML output. By default, according to the standard Markdown syntax these newlines are ignored unless they a preceded by two spaces. Thanks to Jonathan Cohlmeyer for the implementation. * Improved the parsing of list items to fix problematic cases that came to light with the addition of `hard_wrap`. This should have no effect on the output except span-level list items that ended with two spaces (and thus ended with a line break). * Added a `code_span_content_func` configuration variable which takes a function that will convert the content of the code span to HTML. This can be useful to implement syntax highlighting. Although contrary to its code block equivalent, there is no syntax for specifying a language. Credits to styxit for the implementation. * Fixed a Markdown Extra issue where two-space-at-end-of-line hard breaks wouldn't work inside of HTML block elements such as `

` where the element expects only span-level content. * In the parser code, switched to PHPDoc comment format. Thanks to Robbie Averill for the help. PHP Markdown Lib 1.6.0 (23 Dec 2015) Note: this version was incorrectly released as 1.5.1 on Dec 22, a number that contradicted the versioning policy. * For fenced code blocks in Markdown Extra, can now set a class name for the code block's language before the special attribute block. Previously, this class name was only allowed in the absence of the special attribute block. * Added a `code_block_content_func` configuration variable which takes a function that will convert the content of the code block to HTML. This is most useful for syntax highlighting. For fenced code blocks in Markdown Extra, the function has access to the language class name (the one outside of the special attribute block). Credits to Mario Konrad for providing the implementation. * The curled arrow character for the backlink in footnotes is now followed by a Unicode variant selector to prevent it from being displayed in emoji form on iOS. Note that in older browsers the variant selector is often interpreted as a separate character, making it visible after the arrow. So there is now a also a `fn_backlink_html` configuration variable that can be used to set the link text to something else. Credits to Dana for providing the implementation. * Fixed an issue in MarkdownExtra where long header lines followed by a special attribute block would hit the backtrack limit an cause an empty string to be returned. PHP Markdown Lib 1.5.0 (1 Mar 2015) * Added the ability start ordered lists with a number different from 1 and and have that reflected in the HTML output. This can be enabled with the `enhanced_ordered_lists` configuration variable for the Markdown parser; it is enabled by default for Markdown Extra. Credits to Matt Gorle for providing the implementation. * Added the ability to insert custom HTML attributes with simple values everywhere an extra attribute block is allowed (links, images, headers). The value must be unquoted, cannot contains spaces and is limited to alphanumeric ASCII characters. Credits to Peter Droogmans for providing the implementation. * Added a `header_id_func` configuration variable which takes a function that can generate an `id` attribute value from the header text. Credits to Evert Pot for providing the implementation. * Added a `url_filter_func` configuration variable which takes a function that can rewrite any link or image URL to something different. PHP Markdown Lib 1.4.1 (4 May 2014) * The HTML block parser will now treat `

` as a block-level element (as it should) and no longer wrap it in `

` or parse it's content with the as Markdown syntax (although with Extra you can use `markdown="1"` if you wish to use the Markdown syntax inside it). * The content of `