silverstripe-docsviewer/code/DocumentationParser.php

540 lines
19 KiB
PHP
Executable File

<?php
/**
* Parser wrapping the Markdown Extra parser.
*
* @see http://michelf.com/projects/php-markdown/extra/
*
* @package docsviewer
*/
class DocumentationParser
{
const CODE_BLOCK_BACKTICK = 1;
const CODE_BLOCK_COLON = 2;
/**
* @var array
*/
public static $heading_counts = array();
/**
* Parse a given path to the documentation for a file. Performs a case
* insensitive lookup on the file system. Automatically appends the file
* extension to one of the markdown extensions as well so /install/ in a
* web browser will match /install.md or /INSTALL.md.
*
* Filepath: /var/www/myproject/src/cms/en/folder/subfolder/page.md
* URL: http://myhost/mywebroot/dev/docs/2.4/cms/en/folder/subfolder/page
* Webroot: http://myhost/mywebroot/
* Baselink: dev/docs/2.4/cms/en/
* Pathparts: folder/subfolder/page
*
* @param DocumentationPage $page
* @param String $baselink Link relative to webroot, up until the "root"
* of the module. Necessary to rewrite relative
* links
*
* @return String
*/
public static function parse(DocumentationPage $page, $baselink = null)
{
if (!$page || (!$page instanceof DocumentationPage)) {
return false;
}
$md = $page->getMarkdown(true);
// Pre-processing
$md = self::rewrite_image_links($md, $page);
$md = self::rewrite_relative_links($md, $page, $baselink);
$md = self::rewrite_api_links($md, $page);
$md = self::rewrite_heading_anchors($md, $page);
$md = self::rewrite_code_blocks($md);
$parser = new ParsedownExtra();
$parser->setBreaksEnabled(false);
$text = $parser->text($md);
return $text;
}
public static function rewrite_code_blocks($md)
{
$started = false;
$inner = false;
$mode = false;
$end = false;
$debug = false;
$lines = explode("\n", $md);
$output = array();
foreach ($lines as $i => $line) {
if ($debug) {
var_dump('Line '. ($i + 1) . ' '. $line);
}
// if line just contains whitespace, continue down the page.
// Prevents code blocks with leading tabs adding an extra line.
if (preg_match('/^\s$/', $line) && !$started) {
continue;
}
if (!$started && preg_match('/^[\t]*:::\s*(.*)/', $line, $matches)) {
// first line with custom formatting
if ($debug) {
var_dump('Starts a new block with :::');
}
$started = true;
$mode = self::CODE_BLOCK_COLON;
$output[$i] = sprintf('```%s', (isset($matches[1])) ? trim($matches[1]) : "");
} elseif (!$started && preg_match('/^\t*```\s*(.*)/', $line, $matches)) {
if ($debug) {
var_dump('Starts a new block with ```');
}
$started = true;
$mode = self::CODE_BLOCK_BACKTICK;
$output[$i] = sprintf('```%s', (isset($matches[1])) ? trim($matches[1]) : "");
} elseif ($started && $mode == self::CODE_BLOCK_BACKTICK) {
// inside a backtick fenced box
if (preg_match('/^\t*```\s*/', $line, $matches)) {
if ($debug) {
var_dump('End a block with ```');
}
// end of the backtick fenced box. Unset the line that contains the backticks
$end = true;
} else {
if ($debug) {
var_dump('Still in a block with ```');
}
// still inside the line.
if (!$started) {
$output[$i - 1] = '```';
}
$output[$i] = $line;
$inner = true;
}
} elseif (preg_match('/^[\ ]{0,3}?[\t](.*)/', $line, $matches)) {
// inner line of block, or first line of standard markdown code block
// regex removes first tab (any following tabs are part of the code).
if (!$started) {
if ($debug) {
var_dump('Start code block because of tab. No fence');
}
$output[$i - 1] = '```';
} else {
if ($debug) {
var_dump('Content is still tabbed so still inner');
}
}
$output[$i] = $matches[1];
$inner = true;
$started = true;
} elseif ($started && $inner && trim($line) === "") {
if ($debug) {
var_dump('Inner line of code block');
}
// still inside a colon based block, if the line is only whitespace
// then continue with with it. We can continue with it for now as
// it'll be tidied up later in the $end section.
$inner = true;
$output[$i] = $line;
} elseif ($started && $inner) {
// line contains something other than whitespace, or tabbed. E.g
// > code
// > \n
// > some message
//
// So actually want to reset $i to the line before this new line
// and include this line. The edge case where this will fail is
// new the following segment contains a code block as well as it
// will not open.
if ($debug) {
var_dump('Contains something that isnt code. So end the code.');
}
$end = true;
$output[$i] = $line;
$i = $i - 1;
} else {
$output[$i] = $line;
}
if ($end) {
if ($debug) {
var_dump('End of code block');
}
$output = self::finalize_code_output($i, $output);
// reset state
$started = $inner = $mode = $end = false;
}
}
if ($started) {
$output = self::finalize_code_output($i+1, $output);
}
return implode("\n", $output);
}
/**
* Adds the closing code backticks. Removes trailing whitespace.
*
* @param int
* @param array
*
* @return array
*/
private static function finalize_code_output($i, $output)
{
if (isset($output[$i]) && trim($output[$i])) {
$output[$i] .= "\n```\n";
} else {
$output[$i] = "```";
}
return $output;
}
public static function rewrite_image_links($md, $page)
{
// Links with titles
$re = '/
!
\[
(.*?) # image title (non greedy)
\]
\(
(.*?) # image url (non greedy)
\)
/x';
preg_match_all($re, $md, $images);
if ($images) {
foreach ($images[0] as $i => $match) {
$title = $images[1][$i];
$url = $images[2][$i];
// Don't process absolute links (based on protocol detection)
$urlParts = parse_url($url);
if ($urlParts && isset($urlParts['scheme'])) {
continue;
}
// Rewrite URL (relative or absolute)
$baselink = DocumentationHelper::relativePath(
dirname($page->getPath())
);
// if the image starts with a slash, it's absolute
if (substr($url, 0, 1) == '/') {
$relativeUrl = str_replace(BASE_PATH, '', Controller::join_links(
$page->getEntity()->getPath(),
$url
));
} else {
$relativeUrl = rtrim($baselink, '/') . '/' . ltrim($url, '/');
}
// Resolve relative paths
while (strpos($relativeUrl, '/..') !== false) {
$relativeUrl = preg_replace('/\w+\/\.\.\//', '', $relativeUrl);
}
// Make it absolute again
$absoluteUrl = Controller::join_links(
Director::absoluteBaseURL(),
$relativeUrl
);
// Replace any double slashes (apart from protocol)
// $absoluteUrl = preg_replace('/([^:])\/{2,}/', '$1/', $absoluteUrl);
// Replace in original content
$md = str_replace(
$match,
sprintf('![%s](%s)', $title, $absoluteUrl),
$md
);
}
}
return $md;
}
/**
* Rewrite links with special "api:" prefix to html as in the following example:
*
* (1) [api:DataObject] gets re-written to
* <a href="https://api.silverstripe.org/search/lookup/?q=DataObject&version=2.4&module=framework">DataObject</a>
* (2) [api:DataObject::$defaults] gets re-written to
* <a href="https://api.silverstripe.org/search/lookup/?q=DataObject::$defaults&version=2.4&module=framework">DataObject::$defaults</a>
* (3) [api:DataObject::populateDefaults()] gets re-written to
* <a href="https://api.silverstripe.org/search/lookup/?q=DataObject::populateDefaults()&version=2.4&module=framework">DataObject::$defaults</a>
* (4) [Title](api:DataObject) gets re-written to
* <a href="https://api.silverstripe.org/search/lookup/?q=DataObject&version=2.4&module=framework">Title</a>
* (5) [Title](api:DataObject::$defaults) gets re-written to
* <a href="https://api.silverstripe.org/search/lookup/?q=DataObject::$defaults&version=2.4&module=framework">Title</a>
* (6) [Title](api:DataObject->populateDefaults()) gets re-written to
* <a href="https://api.silverstripe.org/search/lookup/?q=DataObject::populateDefaults()&version=2.4&module=framework">Title</a>
*
* The above api links can be enclosed in backticks.
*
* The markdown parser gets confused by the extra pair of parentheses in links of the form [DataObject](api:DataObject::populateDefaults()) so
* all links are re-written as html markup instead of markdown [Title](url). This also prevents other markdown parsing problems.
*
* @param String $markdown
* @param DocumentationPage $doc_page
* @return String
*/
public static function rewrite_api_links($markdown, $doc_page)
{
$version = $doc_page->getVersion();
$module = $doc_page->getEntity()->getKey();
// define regexs of the api links to be parsed (note: do not include backticks)
$regexs = array(
'title_and_method' => '# \[ ([^\]]*) \] \( api: ([^\)]*\(\)) \) #x', // title_and_method = (6) (must be first)
'title_remaining' => '# \[ ([^\]]*) \] \( api: ([^\)]*) \) #x', // title_and_remaining = (4) and (5)
'no_title' => '# \[ api: ([^\]]*) \] #x' // no_title = (1),(2) and (3)
);
// define output format for parsing api links without backticks into html
$html_format = '<a href="http://api.silverstripe.org/search/lookup/?q=%s&version=%s&module=%s">%s</a>';
// parse api links without backticks into html
foreach($regexs as $type => $regex) {
preg_match_all($regex, $markdown, $links);
if($links) {
foreach($links[0] as $i => $match) {
if($type === 'no_title'){
$title = $links[1][$i];
$link = $links[1][$i];
// change backticked links to avoid being parsed in the same way as non-backticked links
$markdown = str_replace('`'.$match.'`','XYZ'.$link.'XYZ',$markdown);
} else {
$title = $links[1][$i];
$link = $links[2][$i];
// change backticked links to avoid being parsed in the same way as non-backticked links
$markdown = str_replace('`'.$match.'`','XX'.$title.'YY'.$link.'ZZ',$markdown);
}
$html = sprintf($html_format, $link, $version, $module, $title);
$markdown = str_replace($match,$html,$markdown);
}
}
}
// recover backticked links with no titles
preg_match_all('#XYZ(.*)?XYZ#', $markdown, $links);
if($links) {
foreach($links[0] as $i => $match) {
$link = $links[1][$i];
$markdown = str_replace($match,'`[api:'.$link.']`',$markdown);
}
}
// recover backticked links with titles
preg_match_all('#XX(.*)?YY(.*)?ZZ#', $markdown, $links);
if($links) {
foreach($links[0] as $i => $match) {
$title = $links[1][$i];
$link = $links[2][$i];
$markdown = str_replace($match,'`['.$title.'](api:'.$link.')`',$markdown);
}
}
return $markdown;
}
/**
*
*/
public static function rewrite_heading_anchors($md, $page)
{
$re = '/^\#+(.*)/m';
$md = preg_replace_callback($re, array('DocumentationParser', '_rewrite_heading_anchors_callback'), $md);
return $md;
}
/**
*
*/
public static function _rewrite_heading_anchors_callback($matches)
{
$heading = $matches[0];
$headingText = $matches[1];
if (preg_match('/\{\#.*\}/', $headingText)) {
return $heading;
}
if (!isset(self::$heading_counts[$headingText])) {
self::$heading_counts[$headingText] = 1;
} else {
self::$heading_counts[$headingText]++;
$headingText .= "-" . self::$heading_counts[$headingText];
}
return sprintf("%s {#%s}", preg_replace('/\n/', '', $heading), self::generate_html_id($headingText));
}
/**
* Generate an html element id from a string
*
* @return String
*/
public static function generate_html_id($title)
{
$t = $title;
$t = str_replace('&amp;', '-and-', $t);
$t = str_replace('&', '-and-', $t);
$t = preg_replace('/[^A-Za-z0-9]+/', '-', $t);
$t = preg_replace('/-+/', '-', $t);
$t = trim($t, '-');
$t = strtolower($t);
return $t;
}
/**
* Resolves all relative links within markdown.
*
* @param String $md Markdown content
* @param DocumentationPage $page
*
* @return String Markdown
*/
public static function rewrite_relative_links($md, $page)
{
$baselink = $page->getEntity()->Link();
$re = '/
([^\!]?) # exclude image format
\[
(.*?) # link title (non greedy)
\]
\(
(.*?) # link url (non greedy)
\)
/x';
preg_match_all($re, $md, $matches);
// relative path (relative to module base folder), without the filename.
// For "sapphire/en/current/topics/templates", this would be "templates"
$relativePath = DocumentationHelper::normalizePath(dirname($page->getRelativePath()));
if (strpos($page->getRelativePath(), 'index.md')) {
$relativeLink = $page->getRelativeLink();
} else {
$relativeLink = DocumentationHelper::normalizePath(dirname($page->getRelativeLink()));
}
if ($relativePath == '.') {
$relativePath = '';
}
if ($relativeLink == ".") {
$relativeLink = '';
}
// file base link
$fileBaseLink = DocumentationHelper::relativePath(DocumentationHelper::normalizePath(dirname($page->getPath())));
if ($matches) {
foreach ($matches[0] as $i => $match) {
$title = $matches[2][$i];
$url = $matches[3][$i];
// Don't process API links
if (preg_match('/^api:/', $url)) {
continue;
}
// Don't process absolute links (based on protocol detection)
$urlParts = parse_url($url);
if ($urlParts && isset($urlParts['scheme'])) {
continue;
}
// for images we need to use the file base path
if (preg_match('/_images/', $url)) {
$relativeUrl = Controller::join_links(
Director::absoluteBaseURL(),
$fileBaseLink,
$url
);
} else {
// Rewrite public URL
if (preg_match('/^\//', $url)) {
// Absolute: Only path to module base
$relativeUrl = Controller::join_links($baselink, $url, '/');
} else {
// Relative: Include path to module base and any folders
$relativeUrl = Controller::join_links($baselink, $relativeLink, $url, '/');
}
}
// Resolve relative paths
while (strpos($relativeUrl, '..') !== false) {
$relativeUrl = preg_replace('/[-\w]+\/\.\.\//', '', $relativeUrl);
}
// Replace any double slashes (apart from protocol)
$relativeUrl = preg_replace('/([^:])\/{2,}/', '$1/', $relativeUrl);
// Replace in original content
$md = str_replace(
$match,
sprintf('%s[%s](%s)', $matches[1][$i], $title, $relativeUrl),
$md
);
}
}
return $md;
}
/**
* Strips out the metadata for a page
*
* @param DocumentationPage
*/
public static function retrieve_meta_data(DocumentationPage &$page)
{
if ($md = $page->getMarkdown()) {
$matches = preg_match_all('/
(?<key>[A-Za-z0-9_-]+):
\s*
(?<value>.*)
/x', $md, $meta);
if ($matches) {
foreach ($meta['key'] as $index => $key) {
if (isset($meta['value'][$index])) {
$page->setMetaData($key, $meta['value'][$index]);
}
}
}
}
}
}