PDF export: add option to export one page per fragment

Author: koehlma

js/reveal.js

@@ -727,14 +727,39 @@
 					numberElement.innerHTML = formatSlideNumber( slideNumberH, '.', slideNumberV );
 					page.appendChild( numberElement );
 				}
+
+				// Copy page and show fragments one after another
+				if ( isPrintingPDFFragments() ) {
+
+					var numberOfFragments = toArray( page.querySelectorAll( '.fragment' ) ).length;
+
+					for ( var currentFragment = 0; currentFragment < numberOfFragments; currentFragment++ ) {
+                        var clonedPage = page.cloneNode( true );
+                        page.parentNode.insertBefore( clonedPage, page.nextSibling );
+
+                        toArray( sortFragments( clonedPage.querySelectorAll( '.fragment' ))).forEach( function ( fragment, fragmentIndex ) {
+                            if ( fragmentIndex <= currentFragment ) {
+                                fragment.classList.add( 'visible' );
+                            } else {
+                                fragment.classList.remove( 'visible' );
+                            }
+                        } );
+
+                        page = clonedPage;
+                    }
+
+				}
+				// Show all fragments
+				else {
+					toArray( page.querySelectorAll( '.fragment' ) ).forEach( function( fragment ) {
+						fragment.classList.add( 'visible' );
+					} );
+				}
+
 			}
 
 		} );
 
-		// Show all fragments
-		toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ' .fragment' ) ).forEach( function( fragment ) {
-			fragment.classList.add( 'visible' );
-		} );
 
 		// Notify subscribers that the PDF layout is good to go
 		dispatchEvent( 'pdf-ready' );
@@ -1497,6 +1522,15 @@
 
 	}
 
+    /**
+	 * Check if this instance is being used to print a PDF with fragments.
+     */
+    function isPrintingPDFFragments() {
+
+    	return ( /print-pdf-fragments/gi ).test( window.location.search );
+
+	}
+
 	/**
 	 * Hides the address bar if we're on a mobile device.
 	 */