4 PHP Markdown Lib 1.7.0 - 29 Oct 2016
9 based on Markdown by John Gruber
10 <https://daringfireball.net/>
16 This is a library package that includes the PHP Markdown parser and its
17 sibling PHP Markdown Extra with additional features.
19 Markdown is a text-to-HTML conversion tool for web writers. Markdown
20 allows you to write using an easy-to-read, easy-to-write plain text
21 format, then convert it to structurally valid XHTML (or HTML).
23 "Markdown" is actually two things: a plain text markup syntax, and a
24 software tool, originally written in Perl, that converts the plain text
25 markup to HTML. PHP Markdown is a port to PHP of the original Markdown
26 program by John Gruber.
28 * [Full documentation of the Markdown syntax](<https://daringfireball.net/projects/markdown/>)
29 — Daring Fireball (John Gruber)
30 * [Markdown Extra syntax additions](<https://michelf.ca/projects/php-markdown/extra/>)
37 This library package requires PHP 5.3 or later.
39 Note: The older plugin/library hybrid package for PHP Markdown and
40 PHP Markdown Extra is still maintained and will work with PHP 4.0.5 and later.
42 Before PHP 5.3.7, pcre.backtrack_limit defaults to 100 000, which is too small
43 in many situations. You might need to set it to higher values. Later PHP
44 releases defaults to 1 000 000, which is usually fine.
50 This library package is meant to be used with class autoloading. For autoloading
51 to work, your project needs have setup a PSR-0-compatible autoloader. See the
52 included Readme.php file for a minimal autoloader setup. (If you cannot use
53 autoloading, see below.)
55 With class autoloading in place, putting the 'Michelf' folder in your
56 include path should be enough for this to work:
58 use \Michelf\Markdown;
59 $my_html = Markdown::defaultTransform($my_text);
61 Markdown Extra syntax is also available the same way:
63 use \Michelf\MarkdownExtra;
64 $my_html = MarkdownExtra::defaultTransform($my_text);
66 If you wish to use PHP Markdown with another text filter function
67 built to parse HTML, you should filter the text *after* the `transform`
68 function call. This is an example with [PHP SmartyPants][psp]:
70 use \Michelf\Markdown, \Michelf\SmartyPants;
71 $my_html = Markdown::defaultTransform($my_text);
72 $my_html = SmartyPants::defaultTransform($my_html);
74 All these examples are using the static `defaultTransform` static function
75 found inside the parser class. If you want to customize the parser
76 configuration, you can also instantiate it directly and change some
77 configuration variables:
79 use \Michelf\MarkdownExtra;
80 $parser = new MarkdownExtra;
81 $parser->fn_id_prefix = "post22-";
82 $my_html = $parser->transform($my_text);
84 To learn more, see the full list of [configuration variables].
86 [configuration variables]: https://michelf.ca/projects/php-markdown/configuration/
89 ### Usage without an autoloader
91 If you cannot use class autoloading, you can still use `include` or `require`
92 to access the parser. To load the `\Michelf\Markdown` parser, do it this way:
94 require_once 'Michelf/Markdown.inc.php';
96 Or, if you need the `\Michelf\MarkdownExtra` parser:
98 require_once 'Michelf/MarkdownExtra.inc.php';
100 While the plain `.php` files depend on autoloading to work correctly, using the
101 `.inc.php` files instead will eagerly load the dependencies that would be
102 loaded on demand if you were using autoloading.
105 Public API and Versioning Policy
106 ---------------------------------
108 Version numbers are of the form *major*.*minor*.*patch*.
110 The public API of PHP Markdown consist of the two parser classes `Markdown`
111 and `MarkdownExtra`, their constructors, the `transform` and `defaultTransform`
112 functions and their configuration variables. The public API is stable for
113 a given major version number. It might get additions when the minor version
116 **Protected members are not considered public API.** This is unconventional
117 and deserves an explanation. Incrementing the major version number every time
118 the underlying implementation of something changes is going to give
119 nonessential version numbers for the vast majority of people who just use the
120 parser. Protected members are meant to create parser subclasses that behave in
121 different ways. Very few people create parser subclasses. I don't want to
122 discourage it by making everything private, but at the same time I can't
123 guarantee any stable hook between versions if you use protected members.
125 **Syntax changes** will increment the minor number for new features, and the
126 patch number for small corrections. A *new feature* is something that needs a
127 change in the syntax documentation. Note that since PHP Markdown Lib includes
128 two parsers, a syntax change for either of them will increment the minor
129 number. Also note that there is nothing perfectly backward-compatible with the
130 Markdown syntax: all inputs are always valid, so new features always replace
131 something that was previously legal, although generally nonsensical to do.
137 To file bug reports please send email to:
138 <michel.fortin@michelf.ca>
140 Please include with your report: (1) the example input; (2) the output you
141 expected; (3) the output PHP Markdown actually produced.
143 If you have a problem where Markdown gives you an empty result, first check
144 that the backtrack limit is not too low by running `php --info | grep pcre`.
145 See Installation and Requirement above for details.
148 Development and Testing
149 -----------------------
151 Pull requests for fixing bugs are welcome. Proposed new features are
152 going to be meticulously reviewed -- taking into account backward compatibility,
153 potential side effects, and future extensibility -- before deciding on
154 acceptance or rejection.
156 If you make a pull request that includes changes to the parser please add
157 tests for what is being changed to [MDTest][] and make a pull request there
160 [MDTest]: https://github.com/michelf/mdtest/
166 If you wish to make a donation that will help me devote more time to
167 PHP Markdown, please visit [michelf.ca/donate] or send Bitcoin to
168 [1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH].
170 [michelf.ca/donate]: https://michelf.ca/donate/#!Thanks%20for%20PHP%20Markdown
171 [1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH]: bitcoin:1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH
177 PHP Markdown Lib 1.7.0 (29 Oct 2016)
179 * Added a `hard_wrap` configuration variable to make all newline characters
180 in the text become `<br>` tags in the HTML output. By default, according
181 to the standard Markdown syntax these newlines are ignored unless they a
182 preceded by two spaces. Thanks to Jonathan Cohlmeyer for the implementation.
184 * Improved the parsing of list items to fix problematic cases that came to
185 light with the addition of `hard_wrap`. This should have no effect on the
186 output except span-level list items that ended with two spaces (and thus
187 ended with a line break).
189 * Added a `code_span_content_func` configuration variable which takes a
190 function that will convert the content of the code span to HTML. This can
191 be useful to implement syntax highlighting. Although contrary to its
192 code block equivalent, there is no syntax for specifying a language.
193 Credits to styxit for the implementation.
195 * Fixed a Markdown Extra issue where two-space-at-end-of-line hard breaks
196 wouldn't work inside of HTML block elements such as `<p markdown="1">`
197 where the element expects only span-level content.
199 * In the parser code, switched to PHPDoc comment format. Thanks to
200 Robbie Averill for the help.
203 PHP Markdown Lib 1.6.0 (23 Dec 2015)
205 Note: this version was incorrectly released as 1.5.1 on Dec 22, a number
206 that contradicted the versioning policy.
208 * For fenced code blocks in Markdown Extra, can now set a class name for the
209 code block's language before the special attribute block. Previously, this
210 class name was only allowed in the absence of the special attribute block.
212 * Added a `code_block_content_func` configuration variable which takes a
213 function that will convert the content of the code block to HTML. This is
214 most useful for syntax highlighting. For fenced code blocks in Markdown
215 Extra, the function has access to the language class name (the one outside
216 of the special attribute block). Credits to Mario Konrad for providing the
219 * The curled arrow character for the backlink in footnotes is now followed
220 by a Unicode variant selector to prevent it from being displayed in emoji
223 Note that in older browsers the variant selector is often interpreted as a
224 separate character, making it visible after the arrow. So there is now a
225 also a `fn_backlink_html` configuration variable that can be used to set
226 the link text to something else. Credits to Dana for providing the
229 * Fixed an issue in MarkdownExtra where long header lines followed by a
230 special attribute block would hit the backtrack limit an cause an empty
231 string to be returned.
234 PHP Markdown Lib 1.5.0 (1 Mar 2015)
236 * Added the ability start ordered lists with a number different from 1 and
237 and have that reflected in the HTML output. This can be enabled with
238 the `enhanced_ordered_lists` configuration variable for the Markdown
239 parser; it is enabled by default for Markdown Extra.
240 Credits to Matt Gorle for providing the implementation.
242 * Added the ability to insert custom HTML attributes with simple values
243 everywhere an extra attribute block is allowed (links, images, headers).
244 The value must be unquoted, cannot contains spaces and is limited to
245 alphanumeric ASCII characters.
246 Credits to Peter Droogmans for providing the implementation.
248 * Added a `header_id_func` configuration variable which takes a function
249 that can generate an `id` attribute value from the header text.
250 Credits to Evert Pot for providing the implementation.
252 * Added a `url_filter_func` configuration variable which takes a function
253 that can rewrite any link or image URL to something different.
256 PHP Markdown Lib 1.4.1 (4 May 2014)
258 * The HTML block parser will now treat `<figure>` as a block-level element
259 (as it should) and no longer wrap it in `<p>` or parse it's content with
260 the as Markdown syntax (although with Extra you can use `markdown="1"`
261 if you wish to use the Markdown syntax inside it).
263 * The content of `<style>` elements will now be left alone, its content
264 won't be interpreted as Markdown.
266 * Corrected an bug where some inline links with spaces in them would not
267 work even when surounded with angle brackets:
269 [link](<s p a c e s>)
271 * Fixed an issue where email addresses with quotes in them would not always
272 have the quotes escaped in the link attribute, causing broken links (and
275 * Fixed the case were a link definition following a footnote definition would
276 be swallowed by the footnote unless it was separated by a blank line.
279 PHP Markdown Lib 1.4.0 (29 Nov 2013)
281 * Added support for the `tel:` URL scheme in automatic links.
283 <tel:+1-111-111-1111>
285 It gets converted to this (note the `tel:` prefix becomes invisible):
287 <a href="tel:+1-111-111-1111">+1-111-111-1111</a>
289 * Added backtick fenced code blocks to MarkdownExtra, originally from
290 Github-Flavored Markdown.
292 * Added an interface called MarkdownInterface implemented by both
293 the Markdown and MarkdownExtra parsers. You can use the interface if
294 you want to create a mockup parser object for unit testing.
296 * For those of you who cannot use class autoloading, you can now
297 include `Michelf/Markdown.inc.php` or `Michelf/MarkdownExtra.inc.php` (note
298 the `.inc.php` extension) to automatically include other files required
302 PHP Markdown Lib 1.3 (11 Apr 2013)
304 This is the first release of PHP Markdown Lib. This package requires PHP
305 version 5.3 or later and is designed to work with PSR-0 autoloading and,
306 optionally with Composer. Here is a list of the changes since
307 PHP Markdown Extra 1.2.6:
309 * Plugin interface for WordPress and other systems is no longer present in
310 the Lib package. The classic package is still available if you need it:
311 <https://michelf.ca/projects/php-markdown/classic/>
313 * Added `public` and `protected` protection attributes, plus a section about
314 what is "public API" and what isn't in the Readme file.
316 * Changed HTML output for footnotes: now instead of adding `rel` and `rev`
317 attributes, footnotes links have the class name `footnote-ref` and
318 backlinks `footnote-backref`.
320 * Fixed some regular expressions to make PCRE not shout warnings about POSIX
321 collation classes (dependent on your version of PCRE).
323 * Added optional class and id attributes to images and links using the same
324 syntax as for headers:
326 [link](url){#id .class}
327 ![img](url){#id .class}
329 It work too for reference-style links and images. In this case you need
330 to put those attributes at the reference definition:
332 [link][linkref] or [linkref]
335 [linkref]: url "optional title" {#id .class}
337 * Fixed a PHP notice message triggered when some table column separator
338 markers are missing on the separator line below column headers.
340 * Fixed a small mistake that could cause the parser to retain an invalid
341 state related to parsing links across multiple runs. This was never
342 observed (that I know of), but it's still worth fixing.
345 Copyright and License
346 ---------------------
349 Copyright (c) 2004-2016 Michel Fortin
350 <https://michelf.ca/>
354 Copyright (c) 2003-2005 John Gruber
355 <https://daringfireball.net/>
358 Redistribution and use in source and binary forms, with or without
359 modification, are permitted provided that the following conditions are
362 * Redistributions of source code must retain the above copyright
363 notice, this list of conditions and the following disclaimer.
365 * Redistributions in binary form must reproduce the above copyright
366 notice, this list of conditions and the following disclaimer in the
367 documentation and/or other materials provided with the
370 * Neither the name "Markdown" nor the names of its contributors may
371 be used to endorse or promote products derived from this software
372 without specific prior written permission.
374 This software is provided by the copyright holders and contributors "as
375 is" and any express or implied warranties, including, but not limited
376 to, the implied warranties of merchantability and fitness for a
377 particular purpose are disclaimed. In no event shall the copyright owner
378 or contributors be liable for any direct, indirect, incidental, special,
379 exemplary, or consequential damages (including, but not limited to,
380 procurement of substitute goods or services; loss of use, data, or
381 profits; or business interruption) however caused and on any theory of
382 liability, whether in contract, strict liability, or tort (including
383 negligence or otherwise) arising in any way out of the use of this
384 software, even if advised of the possibility of such damage.