From c51ab74d7293642b2b8d5267b9355df6c45e0102 Mon Sep 17 00:00:00 2001
From: VonC <vonc@laposte.net>
Date: Thu, 10 Oct 2013 08:47:32 +0200
Subject: [PATCH] Add attributes in markdown for slide generation.

By default, look for <!-- slide-attributes: xxxx -->.
Whatever 'xxx' is will be added to the section attributes.

You can define your own pattern with 'data-attributes'.
For instance 'data-attributes="^\s*?-- (.*?)$"':
that will be added to the options.

The 'attributes' section is removed from the content of the slide,
so the final markdown doesn't reflect them.
That also means you can add those attributes *anywhere* in the slide

But that allows for *any* attribute to be added for a specifc slide,
like:

- id="plan", for allowing internal link (issue #430)
- data-background="#ff0000"
- data-transition="fade"

You list those attributes on a single line, like

- (default):
` <!-- id="plan" data-background="#ff0000" -->`
- or, with an alternative data-attributes pattern:
` -- id="plan" data-background="#ff0000"`

Again, that line is remove from the final content.
---
 plugin/markdown/markdown.js | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/plugin/markdown/markdown.js b/plugin/markdown/markdown.js
index d6c6c459..b5476aa7 100755
--- a/plugin/markdown/markdown.js
+++ b/plugin/markdown/markdown.js
@@ -27,8 +27,9 @@
 	}
 
 	var DEFAULT_SLIDE_SEPARATOR = '^\n---\n$',
-		DEFAULT_NOTES_SEPARATOR = 'note:';
-		DEFAULT_ELEMENT_ATTRIBUTES_SEPARATOR = '{_\s*?([^}]+?)}';
+		DEFAULT_NOTES_SEPARATOR = 'note:',
+		DEFAULT_ELEMENT_ATTRIBUTES_SEPARATOR = '{_\s*?([^}]+?)}',
+		DEFAULT_SLIDE_ATTRIBUTES_SEPARATOR = '^.*?<!-- slide-attributes: (.*?)-->';
 
 
 	/**
@@ -72,7 +73,7 @@
 				value = attributes[i].value;
 
 			// disregard attributes that are used for markdown loading/parsing
-			if( /data\-(markdown|separator|vertical|notes)/gi.test( name ) ) continue;
+			if( /data\-(markdown|separator|vertical|notes|attributes)/gi.test( name ) ) continue;
 
 			if( value ) {
 				result.push( name + '=' + value );
@@ -96,6 +97,7 @@
 		options.separator = options.separator || DEFAULT_SLIDE_SEPARATOR;
 		options.notesSeparator = options.notesSeparator || DEFAULT_NOTES_SEPARATOR;
 		options.attributes = options.attributes || '';
+		options.slideAttributesSeparator = options.slideAttributesSeparator || DEFAULT_SLIDE_ATTRIBUTES_SEPARATOR;
 
 		return options;
 
@@ -127,14 +129,17 @@
 		options = getSlidifyOptions( options );
 
 		var separatorRegex = new RegExp( options.separator + ( options.verticalSeparator ? '|' + options.verticalSeparator : '' ), 'mg' ),
-			horizontalSeparatorRegex = new RegExp( options.separator );
+			horizontalSeparatorRegex = new RegExp( options.separator ),
+			slideAttributesSeparatorRegex = new RegExp( options.slideAttributesSeparator, 'm');
 
 		var matches,
 			lastIndex = 0,
 			isHorizontal,
 			wasHorizontal = true,
 			content,
-			sectionStack = [];
+			sectionStack = [],
+			matchAttributes,
+			slideAttributes = "";
 
 		// iterate until all blocks between separators are stacked up
 		while( matches = separatorRegex.exec( markdown ) ) {
@@ -176,16 +181,22 @@
 				markdownSections += '<section '+ options.attributes +'>';
 
 				sectionStack[i].forEach( function( child ) {
-					markdownSections += '<section data-markdown>' +  createMarkdownSlide( child, options ) + '</section>';
+					matchAttributes = slideAttributesSeparatorRegex.exec(child);
+					slideAttributes = matchAttributes ? matchAttributes[1] : "";
+					child = matchAttributes ? child.replace(slideAttributesSeparatorRegex,"") : child
+					markdownSections += '<section ' + slideAttributes + ' data-markdown>' +  createMarkdownSlide( child, options ) + '</section>';
 				} );
 
 				markdownSections += '</section>';
 			}
 			else {
-				markdownSections += '<section '+ options.attributes +' data-markdown>' + createMarkdownSlide( sectionStack[i], options ) + '</section>';
+				matchAttributes = slideAttributesSeparatorRegex.exec(sectionStack[i]);
+				slideAttributes = matchAttributes ? matchAttributes[1] : "";
+				content = matchAttributes ? sectionStack[i].replace(slideAttributesSeparatorRegex,"") : sectionStack[i]
+				//console.log('Slide attributes ' + options.slideAttributesSeparator + ' => ' + slideAttributes)
+				markdownSections += '<section '+ options.attributes + ' ' + slideAttributes +' data-markdown>' + createMarkdownSlide( content, options ) + '</section>';
 			}
 		}
-
 		return markdownSections;
 
 	}
@@ -223,7 +234,8 @@
 								separator: section.getAttribute( 'data-separator' ),
 								verticalSeparator: section.getAttribute( 'data-vertical' ),
 								notesSeparator: section.getAttribute( 'data-notes' ),
-								attributes: getForwardedAttributes( section )
+								attributes: getForwardedAttributes( section ),
+								slideAttributesSeparator: section.getAttribute( 'data-attributes' ),
 							});
 
 						}