summaryrefslogtreecommitdiff
path: root/2024-06-18-guix-social/reveal.js/plugin/markdown/plugin.js
diff options
context:
space:
mode:
Diffstat (limited to '2024-06-18-guix-social/reveal.js/plugin/markdown/plugin.js')
-rwxr-xr-x2024-06-18-guix-social/reveal.js/plugin/markdown/plugin.js491
1 files changed, 491 insertions, 0 deletions
diff --git a/2024-06-18-guix-social/reveal.js/plugin/markdown/plugin.js b/2024-06-18-guix-social/reveal.js/plugin/markdown/plugin.js
new file mode 100755
index 0000000..61de615
--- /dev/null
+++ b/2024-06-18-guix-social/reveal.js/plugin/markdown/plugin.js
@@ -0,0 +1,491 @@
+/*!
+ * The reveal.js markdown plugin. Handles parsing of
+ * markdown inside of presentations as well as loading
+ * of external markdown documents.
+ */
+
+import { marked } from 'marked';
+
+const DEFAULT_SLIDE_SEPARATOR = '\r?\n---\r?\n',
+ DEFAULT_VERTICAL_SEPARATOR = null,
+ DEFAULT_NOTES_SEPARATOR = '^\s*notes?:',
+ DEFAULT_ELEMENT_ATTRIBUTES_SEPARATOR = '\\\.element\\\s*?(.+?)$',
+ DEFAULT_SLIDE_ATTRIBUTES_SEPARATOR = '\\\.slide:\\\s*?(\\\S.+?)$';
+
+const SCRIPT_END_PLACEHOLDER = '__SCRIPT_END__';
+
+// match an optional line number offset and highlight line numbers
+// [<line numbers>] or [<offset>: <line numbers>]
+const CODE_LINE_NUMBER_REGEX = /\[\s*((\d*):)?\s*([\s\d,|-]*)\]/;
+
+const HTML_ESCAPE_MAP = {
+ '&': '&amp;',
+ '<': '&lt;',
+ '>': '&gt;',
+ '"': '&quot;',
+ "'": '&#39;'
+};
+
+const Plugin = () => {
+
+ // The reveal.js instance this plugin is attached to
+ let deck;
+
+ /**
+ * Retrieves the markdown contents of a slide section
+ * element. Normalizes leading tabs/whitespace.
+ */
+ function getMarkdownFromSlide( section ) {
+
+ // look for a <script> or <textarea data-template> wrapper
+ const template = section.querySelector( '[data-template]' ) || section.querySelector( 'script' );
+
+ // strip leading whitespace so it isn't evaluated as code
+ let text = ( template || section ).textContent;
+
+ // restore script end tags
+ text = text.replace( new RegExp( SCRIPT_END_PLACEHOLDER, 'g' ), '</script>' );
+
+ const leadingWs = text.match( /^\n?(\s*)/ )[1].length,
+ leadingTabs = text.match( /^\n?(\t*)/ )[1].length;
+
+ if( leadingTabs > 0 ) {
+ text = text.replace( new RegExp('\\n?\\t{' + leadingTabs + '}(.*)','g'), function(m, p1) { return '\n' + p1 ; } );
+ }
+ else if( leadingWs > 1 ) {
+ text = text.replace( new RegExp('\\n? {' + leadingWs + '}(.*)', 'g'), function(m, p1) { return '\n' + p1 ; } );
+ }
+
+ return text;
+
+ }
+
+ /**
+ * Given a markdown slide section element, this will
+ * return all arguments that aren't related to markdown
+ * parsing. Used to forward any other user-defined arguments
+ * to the output markdown slide.
+ */
+ function getForwardedAttributes( section ) {
+
+ const attributes = section.attributes;
+ const result = [];
+
+ for( let i = 0, len = attributes.length; i < len; i++ ) {
+ const name = attributes[i].name,
+ value = attributes[i].value;
+
+ // disregard attributes that are used for markdown loading/parsing
+ if( /data\-(markdown|separator|vertical|notes)/gi.test( name ) ) continue;
+
+ if( value ) {
+ result.push( name + '="' + value + '"' );
+ }
+ else {
+ result.push( name );
+ }
+ }
+
+ return result.join( ' ' );
+
+ }
+
+ /**
+ * Inspects the given options and fills out default
+ * values for what's not defined.
+ */
+ function getSlidifyOptions( options ) {
+ const markdownConfig = deck?.getConfig?.().markdown;
+
+ options = options || {};
+ options.separator = options.separator || markdownConfig?.separator || DEFAULT_SLIDE_SEPARATOR;
+ options.verticalSeparator = options.verticalSeparator || markdownConfig?.verticalSeparator || DEFAULT_VERTICAL_SEPARATOR;
+ options.notesSeparator = options.notesSeparator || markdownConfig?.notesSeparator || DEFAULT_NOTES_SEPARATOR;
+ options.attributes = options.attributes || '';
+
+ return options;
+
+ }
+
+ /**
+ * Helper function for constructing a markdown slide.
+ */
+ function createMarkdownSlide( content, options ) {
+
+ options = getSlidifyOptions( options );
+
+ const notesMatch = content.split( new RegExp( options.notesSeparator, 'mgi' ) );
+
+ if( notesMatch.length === 2 ) {
+ content = notesMatch[0] + '<aside class="notes">' + marked(notesMatch[1].trim()) + '</aside>';
+ }
+
+ // prevent script end tags in the content from interfering
+ // with parsing
+ content = content.replace( /<\/script>/g, SCRIPT_END_PLACEHOLDER );
+
+ return '<script type="text/template">' + content + '</script>';
+
+ }
+
+ /**
+ * Parses a data string into multiple slides based
+ * on the passed in separator arguments.
+ */
+ function slidify( markdown, options ) {
+
+ options = getSlidifyOptions( options );
+
+ const separatorRegex = new RegExp( options.separator + ( options.verticalSeparator ? '|' + options.verticalSeparator : '' ), 'mg' ),
+ horizontalSeparatorRegex = new RegExp( options.separator );
+
+ let matches,
+ lastIndex = 0,
+ isHorizontal,
+ wasHorizontal = true,
+ content,
+ sectionStack = [];
+
+ // iterate until all blocks between separators are stacked up
+ while( matches = separatorRegex.exec( markdown ) ) {
+ const notes = null;
+
+ // determine direction (horizontal by default)
+ isHorizontal = horizontalSeparatorRegex.test( matches[0] );
+
+ if( !isHorizontal && wasHorizontal ) {
+ // create vertical stack
+ sectionStack.push( [] );
+ }
+
+ // pluck slide content from markdown input
+ content = markdown.substring( lastIndex, matches.index );
+
+ if( isHorizontal && wasHorizontal ) {
+ // add to horizontal stack
+ sectionStack.push( content );
+ }
+ else {
+ // add to vertical stack
+ sectionStack[sectionStack.length-1].push( content );
+ }
+
+ lastIndex = separatorRegex.lastIndex;
+ wasHorizontal = isHorizontal;
+ }
+
+ // add the remaining slide
+ ( wasHorizontal ? sectionStack : sectionStack[sectionStack.length-1] ).push( markdown.substring( lastIndex ) );
+
+ let markdownSections = '';
+
+ // flatten the hierarchical stack, and insert <section data-markdown> tags
+ for( let i = 0, len = sectionStack.length; i < len; i++ ) {
+ // vertical
+ if( sectionStack[i] instanceof Array ) {
+ markdownSections += '<section '+ options.attributes +'>';
+
+ sectionStack[i].forEach( function( child ) {
+ markdownSections += '<section data-markdown>' + createMarkdownSlide( child, options ) + '</section>';
+ } );
+
+ markdownSections += '</section>';
+ }
+ else {
+ markdownSections += '<section '+ options.attributes +' data-markdown>' + createMarkdownSlide( sectionStack[i], options ) + '</section>';
+ }
+ }
+
+ return markdownSections;
+
+ }
+
+ /**
+ * Parses any current data-markdown slides, splits
+ * multi-slide markdown into separate sections and
+ * handles loading of external markdown.
+ */
+ function processSlides( scope ) {
+
+ return new Promise( function( resolve ) {
+
+ const externalPromises = [];
+
+ [].slice.call( scope.querySelectorAll( 'section[data-markdown]:not([data-markdown-parsed])') ).forEach( function( section, i ) {
+
+ if( section.getAttribute( 'data-markdown' ).length ) {
+
+ externalPromises.push( loadExternalMarkdown( section ).then(
+
+ // Finished loading external file
+ function( xhr, url ) {
+ section.outerHTML = slidify( xhr.responseText, {
+ separator: section.getAttribute( 'data-separator' ),
+ verticalSeparator: section.getAttribute( 'data-separator-vertical' ),
+ notesSeparator: section.getAttribute( 'data-separator-notes' ),
+ attributes: getForwardedAttributes( section )
+ });
+ },
+
+ // Failed to load markdown
+ function( xhr, url ) {
+ section.outerHTML = '<section data-state="alert">' +
+ 'ERROR: The attempt to fetch ' + url + ' failed with HTTP status ' + xhr.status + '.' +
+ 'Check your browser\'s JavaScript console for more details.' +
+ '<p>Remember that you need to serve the presentation HTML from a HTTP server.</p>' +
+ '</section>';
+ }
+
+ ) );
+
+ }
+ else {
+
+ section.outerHTML = slidify( getMarkdownFromSlide( section ), {
+ separator: section.getAttribute( 'data-separator' ),
+ verticalSeparator: section.getAttribute( 'data-separator-vertical' ),
+ notesSeparator: section.getAttribute( 'data-separator-notes' ),
+ attributes: getForwardedAttributes( section )
+ });
+
+ }
+
+ });
+
+ Promise.all( externalPromises ).then( resolve );
+
+ } );
+
+ }
+
+ function loadExternalMarkdown( section ) {
+
+ return new Promise( function( resolve, reject ) {
+
+ const xhr = new XMLHttpRequest(),
+ url = section.getAttribute( 'data-markdown' );
+
+ const datacharset = section.getAttribute( 'data-charset' );
+
+ // see https://developer.mozilla.org/en-US/docs/Web/API/element.getAttribute#Notes
+ if( datacharset !== null && datacharset !== '' ) {
+ xhr.overrideMimeType( 'text/html; charset=' + datacharset );
+ }
+
+ xhr.onreadystatechange = function( section, xhr ) {
+ if( xhr.readyState === 4 ) {
+ // file protocol yields status code 0 (useful for local debug, mobile applications etc.)
+ if ( ( xhr.status >= 200 && xhr.status < 300 ) || xhr.status === 0 ) {
+
+ resolve( xhr, url );
+
+ }
+ else {
+
+ reject( xhr, url );
+
+ }
+ }
+ }.bind( this, section, xhr );
+
+ xhr.open( 'GET', url, true );
+
+ try {
+ xhr.send();
+ }
+ catch ( e ) {
+ console.warn( 'Failed to get the Markdown file ' + url + '. Make sure that the presentation and the file are served by a HTTP server and the file can be found there. ' + e );
+ resolve( xhr, url );
+ }
+
+ } );
+
+ }
+
+ /**
+ * Check if a node value has the attributes pattern.
+ * If yes, extract it and add that value as one or several attributes
+ * to the target element.
+ *
+ * You need Cache Killer on Chrome to see the effect on any FOM transformation
+ * directly on refresh (F5)
+ * http://stackoverflow.com/questions/5690269/disabling-chrome-cache-for-website-development/7000899#answer-11786277
+ */
+ function addAttributeInElement( node, elementTarget, separator ) {
+
+ const markdownClassesInElementsRegex = new RegExp( separator, 'mg' );
+ const markdownClassRegex = new RegExp( "([^\"= ]+?)=\"([^\"]+?)\"|(data-[^\"= ]+?)(?=[\" ])", 'mg' );
+ let nodeValue = node.nodeValue;
+ let matches,
+ matchesClass;
+ if( matches = markdownClassesInElementsRegex.exec( nodeValue ) ) {
+
+ const classes = matches[1];
+ nodeValue = nodeValue.substring( 0, matches.index ) + nodeValue.substring( markdownClassesInElementsRegex.lastIndex );
+ node.nodeValue = nodeValue;
+ while( matchesClass = markdownClassRegex.exec( classes ) ) {
+ if( matchesClass[2] ) {
+ elementTarget.setAttribute( matchesClass[1], matchesClass[2] );
+ } else {
+ elementTarget.setAttribute( matchesClass[3], "" );
+ }
+ }
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Add attributes to the parent element of a text node,
+ * or the element of an attribute node.
+ */
+ function addAttributes( section, element, previousElement, separatorElementAttributes, separatorSectionAttributes ) {
+
+ if ( element !== null && element.childNodes !== undefined && element.childNodes.length > 0 ) {
+ let previousParentElement = element;
+ for( let i = 0; i < element.childNodes.length; i++ ) {
+ const childElement = element.childNodes[i];
+ if ( i > 0 ) {
+ let j = i - 1;
+ while ( j >= 0 ) {
+ const aPreviousChildElement = element.childNodes[j];
+ if ( typeof aPreviousChildElement.setAttribute === 'function' && aPreviousChildElement.tagName !== "BR" ) {
+ previousParentElement = aPreviousChildElement;
+ break;
+ }
+ j = j - 1;
+ }
+ }
+ let parentSection = section;
+ if( childElement.nodeName === "section" ) {
+ parentSection = childElement ;
+ previousParentElement = childElement ;
+ }
+ if ( typeof childElement.setAttribute === 'function' || childElement.nodeType === Node.COMMENT_NODE ) {
+ addAttributes( parentSection, childElement, previousParentElement, separatorElementAttributes, separatorSectionAttributes );
+ }
+ }
+ }
+
+ if ( element.nodeType === Node.COMMENT_NODE ) {
+ if ( addAttributeInElement( element, previousElement, separatorElementAttributes ) === false ) {
+ addAttributeInElement( element, section, separatorSectionAttributes );
+ }
+ }
+ }
+
+ /**
+ * Converts any current data-markdown slides in the
+ * DOM to HTML.
+ */
+ function convertSlides() {
+
+ const sections = deck.getRevealElement().querySelectorAll( '[data-markdown]:not([data-markdown-parsed])');
+
+ [].slice.call( sections ).forEach( function( section ) {
+
+ section.setAttribute( 'data-markdown-parsed', true )
+
+ const notes = section.querySelector( 'aside.notes' );
+ const markdown = getMarkdownFromSlide( section );
+
+ section.innerHTML = marked( markdown );
+ addAttributes( section, section, null, section.getAttribute( 'data-element-attributes' ) ||
+ section.parentNode.getAttribute( 'data-element-attributes' ) ||
+ DEFAULT_ELEMENT_ATTRIBUTES_SEPARATOR,
+ section.getAttribute( 'data-attributes' ) ||
+ section.parentNode.getAttribute( 'data-attributes' ) ||
+ DEFAULT_SLIDE_ATTRIBUTES_SEPARATOR);
+
+ // If there were notes, we need to re-add them after
+ // having overwritten the section's HTML
+ if( notes ) {
+ section.appendChild( notes );
+ }
+
+ } );
+
+ return Promise.resolve();
+
+ }
+
+ function escapeForHTML( input ) {
+
+ return input.replace( /([&<>'"])/g, char => HTML_ESCAPE_MAP[char] );
+
+ }
+
+ return {
+ id: 'markdown',
+
+ /**
+ * Starts processing and converting Markdown within the
+ * current reveal.js deck.
+ */
+ init: function( reveal ) {
+
+ deck = reveal;
+
+ let { renderer, animateLists, ...markedOptions } = deck.getConfig().markdown || {};
+
+ if( !renderer ) {
+ renderer = new marked.Renderer();
+
+ renderer.code = ( code, language ) => {
+
+ // Off by default
+ let lineNumberOffset = '';
+ let lineNumbers = '';
+
+ // Users can opt in to show line numbers and highlight
+ // specific lines.
+ // ```javascript [] show line numbers
+ // ```javascript [1,4-8] highlights lines 1 and 4-8
+ // optional line number offset:
+ // ```javascript [25: 1,4-8] start line numbering at 25,
+ // highlights lines 1 (numbered as 25) and 4-8 (numbered as 28-32)
+ if( CODE_LINE_NUMBER_REGEX.test( language ) ) {
+ let lineNumberOffsetMatch = language.match( CODE_LINE_NUMBER_REGEX )[2];
+ if (lineNumberOffsetMatch){
+ lineNumberOffset = `data-ln-start-from="${lineNumberOffsetMatch.trim()}"`;
+ }
+
+ lineNumbers = language.match( CODE_LINE_NUMBER_REGEX )[3].trim();
+ lineNumbers = `data-line-numbers="${lineNumbers}"`;
+ language = language.replace( CODE_LINE_NUMBER_REGEX, '' ).trim();
+ }
+
+ // Escape before this gets injected into the DOM to
+ // avoid having the HTML parser alter our code before
+ // highlight.js is able to read it
+ code = escapeForHTML( code );
+
+ // return `<pre><code ${lineNumbers} class="${language}">${code}</code></pre>`;
+
+ return `<pre><code ${lineNumbers} ${lineNumberOffset} class="${language}">${code}</code></pre>`;
+ };
+ }
+
+ if( animateLists === true ) {
+ renderer.listitem = text => `<li class="fragment">${text}</li>`;
+ }
+
+ marked.setOptions( {
+ renderer,
+ ...markedOptions
+ } );
+
+ return processSlides( deck.getRevealElement() ).then( convertSlides );
+
+ },
+
+ // TODO: Do these belong in the API?
+ processSlides: processSlides,
+ convertSlides: convertSlides,
+ slidify: slidify,
+ marked: marked
+ }
+
+};
+
+export default Plugin;