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| 1 | +export const mergeHTMLPlugin = (function () { |
| 2 | + 'use strict'; |
| 3 | + |
| 4 | + var originalStream; |
| 5 | + |
| 6 | + /** |
| 7 | + * @param {string} value |
| 8 | + * @returns {string} |
| 9 | + */ |
| 10 | + function escapeHTML(value) { |
| 11 | + return value |
| 12 | + .replace(/&/g, '&') |
| 13 | + .replace(/</g, '<') |
| 14 | + .replace(/>/g, '>') |
| 15 | + .replace(/"/g, '"') |
| 16 | + .replace(/'/g, '''); |
| 17 | + } |
| 18 | + |
| 19 | + /* plugin itself */ |
| 20 | + |
| 21 | + /** @type {HLJSPlugin} */ |
| 22 | + const mergeHTMLPlugin = { |
| 23 | + // preserve the original HTML token stream |
| 24 | + "before:highlightElement": ({ el }) => { |
| 25 | + originalStream = nodeStream(el); |
| 26 | + }, |
| 27 | + // merge it afterwards with the highlighted token stream |
| 28 | + "after:highlightElement": ({ el, result, text }) => { |
| 29 | + if (!originalStream.length) return; |
| 30 | + |
| 31 | + const resultNode = document.createElement('div'); |
| 32 | + resultNode.innerHTML = result.value; |
| 33 | + result.value = mergeStreams(originalStream, nodeStream(resultNode), text); |
| 34 | + el.innerHTML = result.value; |
| 35 | + } |
| 36 | + }; |
| 37 | + |
| 38 | + /* Stream merging support functions */ |
| 39 | + |
| 40 | + /** |
| 41 | + * @typedef Event |
| 42 | + * @property {'start'|'stop'} event |
| 43 | + * @property {number} offset |
| 44 | + * @property {Node} node |
| 45 | + */ |
| 46 | + |
| 47 | + /** |
| 48 | + * @param {Node} node |
| 49 | + */ |
| 50 | + function tag(node) { |
| 51 | + return node.nodeName.toLowerCase(); |
| 52 | + } |
| 53 | + |
| 54 | + /** |
| 55 | + * @param {Node} node |
| 56 | + */ |
| 57 | + function nodeStream(node) { |
| 58 | + /** @type Event[] */ |
| 59 | + const result = []; |
| 60 | + (function _nodeStream(node, offset) { |
| 61 | + for (let child = node.firstChild; child; child = child.nextSibling) { |
| 62 | + if (child.nodeType === 3) { |
| 63 | + offset += child.nodeValue.length; |
| 64 | + } else if (child.nodeType === 1) { |
| 65 | + result.push({ |
| 66 | + event: 'start', |
| 67 | + offset: offset, |
| 68 | + node: child |
| 69 | + }); |
| 70 | + offset = _nodeStream(child, offset); |
| 71 | + // Prevent void elements from having an end tag that would actually |
| 72 | + // double them in the output. There are more void elements in HTML |
| 73 | + // but we list only those realistically expected in code display. |
| 74 | + if (!tag(child).match(/br|hr|img|input/)) { |
| 75 | + result.push({ |
| 76 | + event: 'stop', |
| 77 | + offset: offset, |
| 78 | + node: child |
| 79 | + }); |
| 80 | + } |
| 81 | + } |
| 82 | + } |
| 83 | + return offset; |
| 84 | + })(node, 0); |
| 85 | + return result; |
| 86 | + } |
| 87 | + |
| 88 | + /** |
| 89 | + * @param {any} original - the original stream |
| 90 | + * @param {any} highlighted - stream of the highlighted source |
| 91 | + * @param {string} value - the original source itself |
| 92 | + */ |
| 93 | + function mergeStreams(original, highlighted, value) { |
| 94 | + let processed = 0; |
| 95 | + let result = ''; |
| 96 | + const nodeStack = []; |
| 97 | + |
| 98 | + function selectStream() { |
| 99 | + if (!original.length || !highlighted.length) { |
| 100 | + return original.length ? original : highlighted; |
| 101 | + } |
| 102 | + if (original[0].offset !== highlighted[0].offset) { |
| 103 | + return (original[0].offset < highlighted[0].offset) ? original : highlighted; |
| 104 | + } |
| 105 | + |
| 106 | + /* |
| 107 | + To avoid starting the stream just before it should stop the order is |
| 108 | + ensured that original always starts first and closes last: |
| 109 | +
|
| 110 | + if (event1 == 'start' && event2 == 'start') |
| 111 | + return original; |
| 112 | + if (event1 == 'start' && event2 == 'stop') |
| 113 | + return highlighted; |
| 114 | + if (event1 == 'stop' && event2 == 'start') |
| 115 | + return original; |
| 116 | + if (event1 == 'stop' && event2 == 'stop') |
| 117 | + return highlighted; |
| 118 | +
|
| 119 | + ... which is collapsed to: |
| 120 | + */ |
| 121 | + return highlighted[0].event === 'start' ? original : highlighted; |
| 122 | + } |
| 123 | + |
| 124 | + /** |
| 125 | + * @param {Node} node |
| 126 | + */ |
| 127 | + function open(node) { |
| 128 | + /** @param {Attr} attr */ |
| 129 | + function attributeString(attr) { |
| 130 | + return ' ' + attr.nodeName + '="' + escapeHTML(attr.value) + '"'; |
| 131 | + } |
| 132 | + // @ts-ignore |
| 133 | + result += '<' + tag(node) + [].map.call(node.attributes, attributeString).join('') + '>'; |
| 134 | + } |
| 135 | + |
| 136 | + /** |
| 137 | + * @param {Node} node |
| 138 | + */ |
| 139 | + function close(node) { |
| 140 | + result += '</' + tag(node) + '>'; |
| 141 | + } |
| 142 | + |
| 143 | + /** |
| 144 | + * @param {Event} event |
| 145 | + */ |
| 146 | + function render(event) { |
| 147 | + (event.event === 'start' ? open : close)(event.node); |
| 148 | + } |
| 149 | + |
| 150 | + while (original.length || highlighted.length) { |
| 151 | + let stream = selectStream(); |
| 152 | + result += escapeHTML(value.substring(processed, stream[0].offset)); |
| 153 | + processed = stream[0].offset; |
| 154 | + if (stream === original) { |
| 155 | + /* |
| 156 | + On any opening or closing tag of the original markup we first close |
| 157 | + the entire highlighted node stack, then render the original tag along |
| 158 | + with all the following original tags at the same offset and then |
| 159 | + reopen all the tags on the highlighted stack. |
| 160 | + */ |
| 161 | + nodeStack.reverse().forEach(close); |
| 162 | + do { |
| 163 | + render(stream.splice(0, 1)[0]); |
| 164 | + stream = selectStream(); |
| 165 | + } while (stream === original && stream.length && stream[0].offset === processed); |
| 166 | + nodeStack.reverse().forEach(open); |
| 167 | + } else { |
| 168 | + if (stream[0].event === 'start') { |
| 169 | + nodeStack.push(stream[0].node); |
| 170 | + } else { |
| 171 | + nodeStack.pop(); |
| 172 | + } |
| 173 | + render(stream.splice(0, 1)[0]); |
| 174 | + } |
| 175 | + } |
| 176 | + return result + escapeHTML(value.substr(processed)); |
| 177 | + } |
| 178 | + |
| 179 | + return mergeHTMLPlugin; |
| 180 | +}()); |
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