added markdown.js plugin.

src/client/js/util/reveal/plugins/markdown.js

@@ -0,0 +1,380 @@
+/**
+ * The reveal.js markdown plugin. Handles parsing of
+ * markdown inside of presentations as well as loading
+ * of external markdown documents.
+ */
+export default function( marked ) {
+
+  var DEFAULT_SLIDE_SEPARATOR = '^\r?\n---\r?\n$',
+    DEFAULT_NOTES_SEPARATOR = 'notes?:',
+    DEFAULT_ELEMENT_ATTRIBUTES_SEPARATOR = '\\\.element\\\s*?(.+?)$',
+    DEFAULT_SLIDE_ATTRIBUTES_SEPARATOR = '\\\.slide:\\\s*?(\\\S.+?)$';
+
+  var SCRIPT_END_PLACEHOLDER = '__SCRIPT_END__';
+
+
+  /**
+   * 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
+    var template = section.querySelector( '[data-template]' ) || section.querySelector( 'script' );
+
+    // strip leading whitespace so it isn't evaluated as code
+    var text = ( template || section ).textContent;
+
+    // restore script end tags
+    text = text.replace( new RegExp( SCRIPT_END_PLACEHOLDER, 'g' ), '</script>' );
+
+    var 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'), '\n' );
+    }
+    else if( leadingWs > 1 ) {
+      text = text.replace( new RegExp('\\n? {' + leadingWs + '}', 'g'), '\n' );
+    }
+
+    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 ) {
+
+    var attributes = section.attributes;
+    var result = [];
+
+    for( var i = 0, len = attributes.length; i < len; i++ ) {
+      var 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 ) {
+
+    options = options || {};
+    options.separator = options.separator || DEFAULT_SLIDE_SEPARATOR;
+    options.notesSeparator = options.notesSeparator || DEFAULT_NOTES_SEPARATOR;
+    options.attributes = options.attributes || '';
+
+    return options;
+
+  }
+
+  /**
+   * Helper function for constructing a markdown slide.
+   */
+  function createMarkdownSlide( content, options ) {
+
+    options = getSlidifyOptions( options );
+
+    var 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 );
+
+    var separatorRegex = new RegExp( options.separator + ( options.verticalSeparator ? '|' + options.verticalSeparator : '' ), 'mg' ),
+      horizontalSeparatorRegex = new RegExp( options.separator );
+
+    var matches,
+      lastIndex = 0,
+      isHorizontal,
+      wasHorizontal = true,
+      content,
+      sectionStack = [];
+
+    // iterate until all blocks between separators are stacked up
+    while( matches = separatorRegex.exec( markdown ) ) {
+      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 ) );
+
+    var markdownSections = '';
+
+    // flatten the hierarchical stack, and insert <section data-markdown> tags
+    for( var 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() {
+
+    var sections = document.querySelectorAll( '[data-markdown]'),
+      section;
+
+    for( var i = 0, len = sections.length; i < len; i++ ) {
+
+      section = sections[i];
+
+      if( section.getAttribute( 'data-markdown' ).length ) {
+
+        var xhr = new XMLHttpRequest(),
+          url = section.getAttribute( 'data-markdown' );
+
+        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() {
+          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 ) {
+
+              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 )
+              });
+
+            }
+            else {
+
+              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>';
+
+            }
+          }
+        };
+
+        xhr.open( 'GET', url, false );
+
+        try {
+          xhr.send();
+        }
+        catch ( e ) {
+          alert( '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 );
+        }
+
+      }
+      else if( section.getAttribute( 'data-separator' ) || section.getAttribute( 'data-separator-vertical' ) || section.getAttribute( 'data-separator-notes' ) ) {
+
+        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 )
+        });
+
+      }
+      else {
+        section.innerHTML = createMarkdownSlide( getMarkdownFromSlide( section ) );
+      }
+    }
+
+  }
+
+  /**
+   * Check if a node value has the attributes pattern.
+   * If yes, extract it and add that value as one or several attributes
+   * the the terget 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 ) {
+
+    var mardownClassesInElementsRegex = new RegExp( separator, 'mg' );
+    var mardownClassRegex = new RegExp( "([^\"= ]+?)=\"([^\"=]+?)\"", 'mg' );
+    var nodeValue = node.nodeValue;
+    if( matches = mardownClassesInElementsRegex.exec( nodeValue ) ) {
+
+      var classes = matches[1];
+      nodeValue = nodeValue.substring( 0, matches.index ) + nodeValue.substring( mardownClassesInElementsRegex.lastIndex );
+      node.nodeValue = nodeValue;
+      while( matchesClass = mardownClassRegex.exec( classes ) ) {
+        elementTarget.setAttribute( matchesClass[1], matchesClass[2] );
+      }
+      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 ) {
+      previousParentElement = element;
+      for( var i = 0; i < element.childNodes.length; i++ ) {
+        childElement = element.childNodes[i];
+        if ( i > 0 ) {
+          j = i - 1;
+          while ( j >= 0 ) {
+            aPreviousChildElement = element.childNodes[j];
+            if ( typeof aPreviousChildElement.setAttribute == 'function' && aPreviousChildElement.tagName != "BR" ) {
+              previousParentElement = aPreviousChildElement;
+              break;
+            }
+            j = j - 1;
+          }
+        }
+        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() {
+
+    var sections = document.querySelectorAll( '[data-markdown]');
+
+    for( var i = 0, len = sections.length; i < len; i++ ) {
+
+      var section = sections[i];
+
+      // Only parse the same slide once
+      if( !section.getAttribute( 'data-markdown-parsed' ) ) {
+
+        section.setAttribute( 'data-markdown-parsed', true )
+
+        var notes = section.querySelector( 'aside.notes' );
+        var 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 );
+        }
+
+      }
+
+    }
+
+  }
+
+  // API
+  return {
+    getMarkdownFromSlide: getMarkdownFromSlide,
+    getForwardedAttributes: getForwardedAttributes,
+    getSlidifyOptions: getSlidifyOptions,
+    createMarkdownSlide: createMarkdownSlide,
+    slidify: slidify,
+    processSlides: processSlides,
+    addAttributeInElement: addAttributeInElement,
+    addAttributes: addAttributes,
+    convertSlides: convertSlides
+  };
+
+};