475 lines
14 KiB
JavaScript
475 lines
14 KiB
JavaScript
/*!
|
|
* 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_NOTES_SEPARATOR = 'notes?:',
|
|
DEFAULT_ELEMENT_ATTRIBUTES_SEPARATOR = '\\\.element\\\s*?(.+?)$',
|
|
DEFAULT_SLIDE_ATTRIBUTES_SEPARATOR = '\\\.slide:\\\s*?(\\\S.+?)$';
|
|
|
|
const SCRIPT_END_PLACEHOLDER = '__SCRIPT_END__';
|
|
|
|
const CODE_LINE_NUMBER_REGEX = /\[([\s\d,|-]*)\]/;
|
|
|
|
const HTML_ESCAPE_MAP = {
|
|
'&': '&',
|
|
'<': '<',
|
|
'>': '>',
|
|
'"': '"',
|
|
"'": '''
|
|
};
|
|
|
|
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
|
|
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 ) ) {
|
|
var 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( scope ) {
|
|
|
|
return new Promise( function( resolve ) {
|
|
|
|
var 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 ) {
|
|
|
|
var xhr = new XMLHttpRequest(),
|
|
url = section.getAttribute( 'data-markdown' );
|
|
|
|
var 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 ) {
|
|
|
|
var mardownClassesInElementsRegex = new RegExp( separator, 'mg' );
|
|
var mardownClassRegex = new RegExp( "([^\"= ]+?)=\"([^\"]+?)\"|(data-[^\"= ]+?)(?=[\" ])", 'mg' );
|
|
var nodeValue = node.nodeValue;
|
|
var matches,
|
|
matchesClass;
|
|
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 ) ) {
|
|
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 ) {
|
|
var previousParentElement = element;
|
|
for( var i = 0; i < element.childNodes.length; i++ ) {
|
|
var childElement = element.childNodes[i];
|
|
if ( i > 0 ) {
|
|
var j = i - 1;
|
|
while ( j >= 0 ) {
|
|
var aPreviousChildElement = element.childNodes[j];
|
|
if ( typeof aPreviousChildElement.setAttribute == 'function' && aPreviousChildElement.tagName != "BR" ) {
|
|
previousParentElement = aPreviousChildElement;
|
|
break;
|
|
}
|
|
j = j - 1;
|
|
}
|
|
}
|
|
var 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 = deck.getRevealElement().querySelectorAll( '[data-markdown]:not([data-markdown-parsed])');
|
|
|
|
[].slice.call( sections ).forEach( function( section ) {
|
|
|
|
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 );
|
|
}
|
|
|
|
} );
|
|
|
|
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 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
|
|
if( CODE_LINE_NUMBER_REGEX.test( language ) ) {
|
|
lineNumbers = language.match( CODE_LINE_NUMBER_REGEX )[1].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}">${code}</code></pre>`;
|
|
};
|
|
}
|
|
|
|
if( animateLists === true ) {
|
|
renderer.listitem = text => `<li class="fragment">${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;
|