/**
* The reveal.js markdown plugin. Handles parsing of
* markdown inside of presentations as well as loading
* of external markdown documents.
*/
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
root.marked = require('./marked');
root.RevealMarkdown = factory(root.marked);
} else if (typeof exports === 'object') {
module.exports = factory(require('./marked'));
} else {
// Browser globals (root is window)
root.RevealMarkdown = factory(root.marked);
}
}(this, 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() {
return new Promise(function (resolve) {
var externalPromises = [];
[].slice.call(document.querySelectorAll('[data-markdown]')).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 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));
}
});
Promise.all(externalPromises).then(resolve);
});
}
function loadExternalMarkdown(section) {
return new Promise(function (resolve, reject) {
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 (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) {
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);
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("([^\"= ]+?)=\"([^\"=]+?)\"", '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]: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();
}
// API
var RevealMarkdown = {
/**
* Starts processing and converting Markdown within the
* current reveal.js deck.
*
* @param {function} callback function to invoke once
* we've finished loading and parsing Markdown
*/
init: function (callback) {
if (typeof marked === 'undefined') {
throw 'The reveal.js Markdown plugin requires marked to be loaded';
}
if (typeof hljs !== 'undefined') {
marked.setOptions({
highlight: function (code, lang) {
return hljs.highlightAuto(code, [lang]).value;
}
});
}
// marked can be configured via reveal.js config options
var options = Reveal.getConfig().markdown;
if (options) {
marked.setOptions(options);
}
return processSlides().then(convertSlides);
},
// TODO: Do these belong in the API?
processSlides: processSlides,
convertSlides: convertSlides,
slidify: slidify
};
// Register our plugin so that reveal.js will call our
// plugin 'init' method as part of the initialization
Reveal.registerPlugin('markdown', RevealMarkdown);
return RevealMarkdown;
}));