bookclub-advr

DSLC Advanced R Book Club
git clone https://git.eamoncaddigan.net/bookclub-advr.git
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plugin.js (16338B)


      1 import hljs from 'highlight.js';
      2 
      3 /* highlightjs-line-numbers.js 2.8.0 | (C) 2018 Yauheni Pakala | MIT License | github.com/wcoder/highlightjs-line-numbers.js */
      4 !function(r,o){"use strict";var e,i="hljs-ln",l="hljs-ln-line",h="hljs-ln-code",s="hljs-ln-numbers",c="hljs-ln-n",m="data-line-number",a=/\r\n|\r|\n/g;function u(e){for(var n=e.toString(),t=e.anchorNode;"TD"!==t.nodeName;)t=t.parentNode;for(var r=e.focusNode;"TD"!==r.nodeName;)r=r.parentNode;var o=parseInt(t.dataset.lineNumber),a=parseInt(r.dataset.lineNumber);if(o==a)return n;var i,l=t.textContent,s=r.textContent;for(a<o&&(i=o,o=a,a=i,i=l,l=s,s=i);0!==n.indexOf(l);)l=l.slice(1);for(;-1===n.lastIndexOf(s);)s=s.slice(0,-1);for(var c=l,u=function(e){for(var n=e;"TABLE"!==n.nodeName;)n=n.parentNode;return n}(t),d=o+1;d<a;++d){var f=p('.{0}[{1}="{2}"]',[h,m,d]);c+="\n"+u.querySelector(f).textContent}return c+="\n"+s}function n(e){try{var n=o.querySelectorAll("code.hljs,code.nohighlight");for(var t in n)n.hasOwnProperty(t)&&(n[t].classList.contains("nohljsln")||d(n[t],e))}catch(e){r.console.error("LineNumbers error: ",e)}}function d(e,n){if("object"==typeof e)e.innerHTML=f(e,n)}function f(e,n){var t,r,o=(t=e,{singleLine:function(e){return!!e.singleLine&&e.singleLine}(r=(r=n)||{}),startFrom:function(e,n){var t=1;isFinite(n.startFrom)&&(t=n.startFrom);var r=function(e,n){return e.hasAttribute(n)?e.getAttribute(n):null}(e,"data-ln-start-from");return null!==r&&(t=function(e,n){if(!e)return n;var t=Number(e);return isFinite(t)?t:n}(r,1)),t}(t,r)});return function e(n){var t=n.childNodes;for(var r in t){var o;t.hasOwnProperty(r)&&(o=t[r],0<(o.textContent.trim().match(a)||[]).length&&(0<o.childNodes.length?e(o):v(o.parentNode)))}}(e),function(e,n){var t=g(e);""===t[t.length-1].trim()&&t.pop();if(1<t.length||n.singleLine){for(var r="",o=0,a=t.length;o<a;o++)r+=p('<tr><td class="{0} {1}" {3}="{5}"><div class="{2}" {3}="{5}"></div></td><td class="{0} {4}" {3}="{5}">{6}</td></tr>',[l,s,c,m,h,o+n.startFrom,0<t[o].length?t[o]:" "]);return p('<table class="{0}">{1}</table>',[i,r])}return e}(e.innerHTML,o)}function v(e){var n=e.className;if(/hljs-/.test(n)){for(var t=g(e.innerHTML),r=0,o="";r<t.length;r++){o+=p('<span class="{0}">{1}</span>\n',[n,0<t[r].length?t[r]:" "])}e.innerHTML=o.trim()}}function g(e){return 0===e.length?[]:e.split(a)}function p(e,t){return e.replace(/\{(\d+)\}/g,function(e,n){return void 0!==t[n]?t[n]:e})}hljs?(hljs.initLineNumbersOnLoad=function(e){"interactive"===o.readyState||"complete"===o.readyState?n(e):r.addEventListener("DOMContentLoaded",function(){n(e)})},hljs.lineNumbersBlock=d,hljs.lineNumbersValue=function(e,n){if("string"!=typeof e)return;var t=document.createElement("code");return t.innerHTML=e,f(t,n)},(e=o.createElement("style")).type="text/css",e.innerHTML=p(".{0}{border-collapse:collapse}.{0} td{padding:0}.{1}:before{content:attr({2})}",[i,c,m]),o.getElementsByTagName("head")[0].appendChild(e)):r.console.error("highlight.js not detected!"),document.addEventListener("copy",function(e){var n,t=window.getSelection();!function(e){for(var n=e;n;){if(n.className&&-1!==n.className.indexOf("hljs-ln-code"))return 1;n=n.parentNode}}(t.anchorNode)||(n=-1!==window.navigator.userAgent.indexOf("Edge")?u(t):t.toString(),e.clipboardData.setData("text/plain",n),e.preventDefault())})}(window,document);
      5 
      6 
      7 /*!
      8  * reveal.js plugin that adds syntax highlight support.
      9  */
     10 
     11 const Plugin = {
     12 
     13 	id: 'highlight',
     14 
     15 	HIGHLIGHT_STEP_DELIMITER: '|',
     16 	HIGHLIGHT_LINE_DELIMITER: ',',
     17 	HIGHLIGHT_LINE_RANGE_DELIMITER: '-',
     18 
     19 	hljs,
     20 
     21 	/**
     22 	 * Highlights code blocks within the given deck.
     23 	 *
     24 	 * Note that this can be called multiple times if
     25 	 * there are multiple presentations on one page.
     26 	 *
     27 	 * @param {Reveal} reveal the reveal.js instance
     28 	 */
     29 	init: function( reveal ) {
     30 
     31 		// Read the plugin config options and provide fallbacks
     32 		let config = reveal.getConfig().highlight || {};
     33 
     34 		config.highlightOnLoad = typeof config.highlightOnLoad === 'boolean' ? config.highlightOnLoad : true;
     35 		config.escapeHTML = typeof config.escapeHTML === 'boolean' ? config.escapeHTML : true;
     36 
     37 		Array.from( reveal.getRevealElement().querySelectorAll( 'pre code' ) ).forEach( block => {
     38 
     39 			block.parentNode.classList.add('code-wrapper');
     40 
     41 			// Code can optionally be wrapped in script template to avoid
     42 			// HTML being parsed by the browser (i.e. when you need to
     43 			// include <, > or & in your code).
     44 			let substitute = block.querySelector( 'script[type="text/template"]' );
     45 			if( substitute ) {
     46 				// textContent handles the HTML entity escapes for us
     47 				block.textContent = substitute.innerHTML;
     48 			}
     49 
     50 			// Trim whitespace if the "data-trim" attribute is present
     51 			if( block.hasAttribute( 'data-trim' ) && typeof block.innerHTML.trim === 'function' ) {
     52 				block.innerHTML = betterTrim( block );
     53 			}
     54 
     55 			// Escape HTML tags unless the "data-noescape" attrbute is present
     56 			if( config.escapeHTML && !block.hasAttribute( 'data-noescape' )) {
     57 				block.innerHTML = block.innerHTML.replace( /</g,"&lt;").replace(/>/g, '&gt;' );
     58 			}
     59 
     60 			// Re-highlight when focus is lost (for contenteditable code)
     61 			block.addEventListener( 'focusout', function( event ) {
     62 				hljs.highlightElement( event.currentTarget );
     63 			}, false );
     64 
     65 		} );
     66 
     67 		// Triggers a callback function before we trigger highlighting
     68 		if( typeof config.beforeHighlight === 'function' ) {
     69 			config.beforeHighlight( hljs );
     70 		}
     71 
     72 		// Run initial highlighting for all code
     73 		if( config.highlightOnLoad ) {
     74 			Array.from( reveal.getRevealElement().querySelectorAll( 'pre code' ) ).forEach( block => {
     75 				Plugin.highlightBlock( block );
     76 			} );
     77 		}
     78 
     79 		// If we're printing to PDF, scroll the code highlights of
     80 		// all blocks in the deck into view at once
     81 		reveal.on( 'pdf-ready', function() {
     82 			[].slice.call( reveal.getRevealElement().querySelectorAll( 'pre code[data-line-numbers].current-fragment' ) ).forEach( function( block ) {
     83 				Plugin.scrollHighlightedLineIntoView( block, {}, true );
     84 			} );
     85 		} );
     86 
     87 	},
     88 
     89 	/**
     90 	 * Highlights a code block. If the <code> node has the
     91 	 * 'data-line-numbers' attribute we also generate slide
     92 	 * numbers.
     93 	 *
     94 	 * If the block contains multiple line highlight steps,
     95 	 * we clone the block and create a fragment for each step.
     96 	 */
     97 	highlightBlock: function( block ) {
     98 
     99 		hljs.highlightElement( block );
    100 
    101 		// Don't generate line numbers for empty code blocks
    102 		if( block.innerHTML.trim().length === 0 ) return;
    103 
    104 		if( block.hasAttribute( 'data-line-numbers' ) ) {
    105 			hljs.lineNumbersBlock( block, { singleLine: true } );
    106 
    107 			var scrollState = { currentBlock: block };
    108 
    109 			// If there is more than one highlight step, generate
    110 			// fragments
    111 			var highlightSteps = Plugin.deserializeHighlightSteps( block.getAttribute( 'data-line-numbers' ) );
    112 			if( highlightSteps.length > 1 ) {
    113 
    114 				// If the original code block has a fragment-index,
    115 				// each clone should follow in an incremental sequence
    116 				var fragmentIndex = parseInt( block.getAttribute( 'data-fragment-index' ), 10 );
    117 
    118 				if( typeof fragmentIndex !== 'number' || isNaN( fragmentIndex ) ) {
    119 					fragmentIndex = null;
    120 				}
    121 
    122 				// Generate fragments for all steps except the original block
    123 				highlightSteps.slice(1).forEach( function( highlight ) {
    124 
    125 					var fragmentBlock = block.cloneNode( true );
    126 					fragmentBlock.setAttribute( 'data-line-numbers', Plugin.serializeHighlightSteps( [ highlight ] ) );
    127 					fragmentBlock.classList.add( 'fragment' );
    128 					block.parentNode.appendChild( fragmentBlock );
    129 					Plugin.highlightLines( fragmentBlock );
    130 
    131 					if( typeof fragmentIndex === 'number' ) {
    132 						fragmentBlock.setAttribute( 'data-fragment-index', fragmentIndex );
    133 						fragmentIndex += 1;
    134 					}
    135 					else {
    136 						fragmentBlock.removeAttribute( 'data-fragment-index' );
    137 					}
    138 
    139 					// Scroll highlights into view as we step through them
    140 					fragmentBlock.addEventListener( 'visible', Plugin.scrollHighlightedLineIntoView.bind( Plugin, fragmentBlock, scrollState ) );
    141 					fragmentBlock.addEventListener( 'hidden', Plugin.scrollHighlightedLineIntoView.bind( Plugin, fragmentBlock.previousElementSibling, scrollState ) );
    142 
    143 				} );
    144 
    145 				block.removeAttribute( 'data-fragment-index' );
    146 				block.setAttribute( 'data-line-numbers', Plugin.serializeHighlightSteps( [ highlightSteps[0] ] ) );
    147 
    148 			}
    149 
    150 			// Scroll the first highlight into view when the slide
    151 			// becomes visible. Note supported in IE11 since it lacks
    152 			// support for Element.closest.
    153 			var slide = typeof block.closest === 'function' ? block.closest( 'section:not(.stack)' ) : null;
    154 			if( slide ) {
    155 				var scrollFirstHighlightIntoView = function() {
    156 					Plugin.scrollHighlightedLineIntoView( block, scrollState, true );
    157 					slide.removeEventListener( 'visible', scrollFirstHighlightIntoView );
    158 				}
    159 				slide.addEventListener( 'visible', scrollFirstHighlightIntoView );
    160 			}
    161 
    162 			Plugin.highlightLines( block );
    163 
    164 		}
    165 
    166 	},
    167 
    168 	/**
    169 	 * Animates scrolling to the first highlighted line
    170 	 * in the given code block.
    171 	 */
    172 	scrollHighlightedLineIntoView: function( block, scrollState, skipAnimation ) {
    173 
    174 		cancelAnimationFrame( scrollState.animationFrameID );
    175 
    176 		// Match the scroll position of the currently visible
    177 		// code block
    178 		if( scrollState.currentBlock ) {
    179 			block.scrollTop = scrollState.currentBlock.scrollTop;
    180 		}
    181 
    182 		// Remember the current code block so that we can match
    183 		// its scroll position when showing/hiding fragments
    184 		scrollState.currentBlock = block;
    185 
    186 		var highlightBounds = this.getHighlightedLineBounds( block )
    187 		var viewportHeight = block.offsetHeight;
    188 
    189 		// Subtract padding from the viewport height
    190 		var blockStyles = getComputedStyle( block );
    191 		viewportHeight -= parseInt( blockStyles.paddingTop ) + parseInt( blockStyles.paddingBottom );
    192 
    193 		// Scroll position which centers all highlights
    194 		var startTop = block.scrollTop;
    195 		var targetTop = highlightBounds.top + ( Math.min( highlightBounds.bottom - highlightBounds.top, viewportHeight ) - viewportHeight ) / 2;
    196 
    197 		// Account for offsets in position applied to the
    198 		// <table> that holds our lines of code
    199 		var lineTable = block.querySelector( '.hljs-ln' );
    200 		if( lineTable ) targetTop += lineTable.offsetTop - parseInt( blockStyles.paddingTop );
    201 
    202 		// Make sure the scroll target is within bounds
    203 		targetTop = Math.max( Math.min( targetTop, block.scrollHeight - viewportHeight ), 0 );
    204 
    205 		if( skipAnimation === true || startTop === targetTop ) {
    206 			block.scrollTop = targetTop;
    207 		}
    208 		else {
    209 
    210 			// Don't attempt to scroll if there is no overflow
    211 			if( block.scrollHeight <= viewportHeight ) return;
    212 
    213 			var time = 0;
    214 			var animate = function() {
    215 				time = Math.min( time + 0.02, 1 );
    216 
    217 				// Update our eased scroll position
    218 				block.scrollTop = startTop + ( targetTop - startTop ) * Plugin.easeInOutQuart( time );
    219 
    220 				// Keep animating unless we've reached the end
    221 				if( time < 1 ) {
    222 					scrollState.animationFrameID = requestAnimationFrame( animate );
    223 				}
    224 			};
    225 
    226 			animate();
    227 
    228 		}
    229 
    230 	},
    231 
    232 	/**
    233 	 * The easing function used when scrolling.
    234 	 */
    235 	easeInOutQuart: function( t ) {
    236 
    237 		// easeInOutQuart
    238 		return t<.5 ? 8*t*t*t*t : 1-8*(--t)*t*t*t;
    239 
    240 	},
    241 
    242 	getHighlightedLineBounds: function( block ) {
    243 
    244 		var highlightedLines = block.querySelectorAll( '.highlight-line' );
    245 		if( highlightedLines.length === 0 ) {
    246 			return { top: 0, bottom: 0 };
    247 		}
    248 		else {
    249 			var firstHighlight = highlightedLines[0];
    250 			var lastHighlight = highlightedLines[ highlightedLines.length -1 ];
    251 
    252 			return {
    253 				top: firstHighlight.offsetTop,
    254 				bottom: lastHighlight.offsetTop + lastHighlight.offsetHeight
    255 			}
    256 		}
    257 
    258 	},
    259 
    260 	/**
    261 	 * Visually emphasize specific lines within a code block.
    262 	 * This only works on blocks with line numbering turned on.
    263 	 *
    264 	 * @param {HTMLElement} block a <code> block
    265 	 * @param {String} [linesToHighlight] The lines that should be
    266 	 * highlighted in this format:
    267 	 * "1" 		= highlights line 1
    268 	 * "2,5"	= highlights lines 2 & 5
    269 	 * "2,5-7"	= highlights lines 2, 5, 6 & 7
    270 	 */
    271 	highlightLines: function( block, linesToHighlight ) {
    272 
    273 		var highlightSteps = Plugin.deserializeHighlightSteps( linesToHighlight || block.getAttribute( 'data-line-numbers' ) );
    274 
    275 		if( highlightSteps.length ) {
    276 
    277 			highlightSteps[0].forEach( function( highlight ) {
    278 
    279 				var elementsToHighlight = [];
    280 
    281 				// Highlight a range
    282 				if( typeof highlight.end === 'number' ) {
    283 					elementsToHighlight = [].slice.call( block.querySelectorAll( 'table tr:nth-child(n+'+highlight.start+'):nth-child(-n+'+highlight.end+')' ) );
    284 				}
    285 				// Highlight a single line
    286 				else if( typeof highlight.start === 'number' ) {
    287 					elementsToHighlight = [].slice.call( block.querySelectorAll( 'table tr:nth-child('+highlight.start+')' ) );
    288 				}
    289 
    290 				if( elementsToHighlight.length ) {
    291 					elementsToHighlight.forEach( function( lineElement ) {
    292 						lineElement.classList.add( 'highlight-line' );
    293 					} );
    294 
    295 					block.classList.add( 'has-highlights' );
    296 				}
    297 
    298 			} );
    299 
    300 		}
    301 
    302 	},
    303 
    304 	/**
    305 	 * Parses and formats a user-defined string of line
    306 	 * numbers to highlight.
    307 	 *
    308 	 * @example
    309 	 * Plugin.deserializeHighlightSteps( '1,2|3,5-10' )
    310 	 * // [
    311 	 * //   [ { start: 1 }, { start: 2 } ],
    312 	 * //   [ { start: 3 }, { start: 5, end: 10 } ]
    313 	 * // ]
    314 	 */
    315 	deserializeHighlightSteps: function( highlightSteps ) {
    316 
    317 		// Remove whitespace
    318 		highlightSteps = highlightSteps.replace( /\s/g, '' );
    319 
    320 		// Divide up our line number groups
    321 		highlightSteps = highlightSteps.split( Plugin.HIGHLIGHT_STEP_DELIMITER );
    322 
    323 		return highlightSteps.map( function( highlights ) {
    324 
    325 			return highlights.split( Plugin.HIGHLIGHT_LINE_DELIMITER ).map( function( highlight ) {
    326 
    327 				// Parse valid line numbers
    328 				if( /^[\d-]+$/.test( highlight ) ) {
    329 
    330 					highlight = highlight.split( Plugin.HIGHLIGHT_LINE_RANGE_DELIMITER );
    331 
    332 					var lineStart = parseInt( highlight[0], 10 ),
    333 						lineEnd = parseInt( highlight[1], 10 );
    334 
    335 					if( isNaN( lineEnd ) ) {
    336 						return {
    337 							start: lineStart
    338 						};
    339 					}
    340 					else {
    341 						return {
    342 							start: lineStart,
    343 							end: lineEnd
    344 						};
    345 					}
    346 
    347 				}
    348 				// If no line numbers are provided, no code will be highlighted
    349 				else {
    350 
    351 					return {};
    352 
    353 				}
    354 
    355 			} );
    356 
    357 		} );
    358 
    359 	},
    360 
    361 	/**
    362 	 * Serializes parsed line number data into a string so
    363 	 * that we can store it in the DOM.
    364 	 */
    365 	serializeHighlightSteps: function( highlightSteps ) {
    366 
    367 		return highlightSteps.map( function( highlights ) {
    368 
    369 			return highlights.map( function( highlight ) {
    370 
    371 				// Line range
    372 				if( typeof highlight.end === 'number' ) {
    373 					return highlight.start + Plugin.HIGHLIGHT_LINE_RANGE_DELIMITER + highlight.end;
    374 				}
    375 				// Single line
    376 				else if( typeof highlight.start === 'number' ) {
    377 					return highlight.start;
    378 				}
    379 				// All lines
    380 				else {
    381 					return '';
    382 				}
    383 
    384 			} ).join( Plugin.HIGHLIGHT_LINE_DELIMITER );
    385 
    386 		} ).join( Plugin.HIGHLIGHT_STEP_DELIMITER );
    387 
    388 	}
    389 
    390 }
    391 
    392 // Function to perform a better "data-trim" on code snippets
    393 // Will slice an indentation amount on each line of the snippet (amount based on the line having the lowest indentation length)
    394 function betterTrim(snippetEl) {
    395 	// Helper functions
    396 	function trimLeft(val) {
    397 		// Adapted from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim#Polyfill
    398 		return val.replace(/^[\s\uFEFF\xA0]+/g, '');
    399 	}
    400 	function trimLineBreaks(input) {
    401 		var lines = input.split('\n');
    402 
    403 		// Trim line-breaks from the beginning
    404 		for (var i = 0; i < lines.length; i++) {
    405 			if (lines[i].trim() === '') {
    406 				lines.splice(i--, 1);
    407 			} else break;
    408 		}
    409 
    410 		// Trim line-breaks from the end
    411 		for (var i = lines.length-1; i >= 0; i--) {
    412 			if (lines[i].trim() === '') {
    413 				lines.splice(i, 1);
    414 			} else break;
    415 		}
    416 
    417 		return lines.join('\n');
    418 	}
    419 
    420 	// Main function for betterTrim()
    421 	return (function(snippetEl) {
    422 		var content = trimLineBreaks(snippetEl.innerHTML);
    423 		var lines = content.split('\n');
    424 		// Calculate the minimum amount to remove on each line start of the snippet (can be 0)
    425 		var pad = lines.reduce(function(acc, line) {
    426 			if (line.length > 0 && trimLeft(line).length > 0 && acc > line.length - trimLeft(line).length) {
    427 				return line.length - trimLeft(line).length;
    428 			}
    429 			return acc;
    430 		}, Number.POSITIVE_INFINITY);
    431 		// Slice each line with this amount
    432 		return lines.map(function(line, index) {
    433 			return line.slice(pad);
    434 		})
    435 		.join('\n');
    436 	})(snippetEl);
    437 }
    438 
    439 export default () => Plugin;