lca20-bt/plugin/markdown/markdown.js
2013-04-20 09:16:41 -04:00

191 lines
6.4 KiB
JavaScript
Executable File

// From https://gist.github.com/1343518
// Modified by Hakim to handle Markdown indented with tabs
(function(){
if( typeof Showdown === 'undefined' ) {
throw 'The reveal.js Markdown plugin requires Showdown to be loaded';
}
var stripLeadingWhitespace = function(section) {
var template = section.querySelector( 'script' );
// strip leading whitespace so it isn't evaluated as code
var text = ( template || section ).textContent;
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;
};
var twrap = function(el) {
return '<script type="text/template">' + el + '</script>';
};
var getForwardedAttributes = function(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)/gi.test( name ) ) continue;
if( value ) {
result.push( name + '=' + value );
}
else {
result.push( name );
}
}
return result.join( ' ' );
}
var slidifyMarkdown = function(markdown, separator, vertical, attributes) {
separator = separator || '^\n---\n$';
var reSeparator = new RegExp(separator + (vertical ? '|' + vertical : ''), 'mg'),
reHorSeparator = new RegExp(separator),
matches,
lastIndex = 0,
isHorizontal,
wasHorizontal = true,
content,
sectionStack = [],
markdownSections = '';
// iterate until all blocks between separators are stacked up
while( matches = reSeparator.exec(markdown) ) {
// determine direction (horizontal by default)
isHorizontal = reHorSeparator.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 = reSeparator.lastIndex;
wasHorizontal = isHorizontal;
}
// add the remaining slide
(wasHorizontal ? sectionStack : sectionStack[sectionStack.length-1]).push(markdown.substring(lastIndex));
// flatten the hierarchical stack, and insert <section data-markdown> tags
for( var k = 0, klen = sectionStack.length; k < klen; k++ ) {
// horizontal
if( typeof sectionStack[k] === 'string' ) {
markdownSections += '<section '+ attributes +' data-markdown>' + twrap( sectionStack[k] ) + '</section>';
}
// vertical
else {
markdownSections += '<section '+ attributes +'>' +
'<section data-markdown>' + sectionStack[k].map(twrap).join('</section><section data-markdown>') + '</section>' +
'</section>';
}
}
return markdownSections;
};
var querySlidingMarkdown = function() {
var sections = document.querySelectorAll( '[data-markdown]'),
section;
for( var j = 0, jlen = sections.length; j < jlen; j++ ) {
section = sections[j];
if( section.getAttribute('data-markdown').length ) {
var xhr = new XMLHttpRequest(),
url = section.getAttribute('data-markdown');
xhr.onreadystatechange = function () {
if( xhr.readyState === 4 ) {
if (xhr.status >= 200 && xhr.status < 300) {
section.outerHTML = slidifyMarkdown( xhr.responseText, section.getAttribute('data-separator'), section.getAttribute('data-vertical'), getForwardedAttributes(section) );
} else {
section.outerHTML = '<section data-state="alert">ERROR: The attempt to fetch ' + url + ' failed with the 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 and the Markdown file must be there too.</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') ) {
var markdown = stripLeadingWhitespace(section);
section.outerHTML = slidifyMarkdown( markdown, section.getAttribute('data-separator'), section.getAttribute('data-vertical'), getForwardedAttributes(section) );
}
}
};
var queryMarkdownSlides = function() {
var sections = document.querySelectorAll( '[data-markdown]');
for( var j = 0, jlen = sections.length; j < jlen; j++ ) {
makeHtml(sections[j]);
}
};
var makeHtml = function(section) {
var notes = section.querySelector( 'aside.notes' );
var markdown = stripLeadingWhitespace(section);
section.innerHTML = (new Showdown.converter()).makeHtml(markdown);
if( notes ) {
section.appendChild( notes );
}
};
querySlidingMarkdown();
queryMarkdownSlides();
})();