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comparison katex/contrib/copy-tex.mjs @ 8:4a25b534c81c javascript-experiment

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Add v8 engine and include katex
author Jonatan Werpers <jonatan@werpers.com>
date Wed, 17 Jun 2020 21:43:52 +0200
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7:a5aa39557726 8:4a25b534c81c
1 // Set these to how you want inline and display math to be delimited.
2 const defaultCopyDelimiters = {
3 inline: ['$', '$'],
4 // alternative: ['\(', '\)']
5 display: ['$$', '$$'] // alternative: ['\[', '\]']
6
7 }; // Replace .katex elements with their TeX source (<annotation> element).
8 // Modifies fragment in-place. Useful for writing your own 'copy' handler,
9 // as in copy-tex.js.
10
11 const katexReplaceWithTex = function katexReplaceWithTex(fragment, copyDelimiters) {
12 if (copyDelimiters === void 0) {
13 copyDelimiters = defaultCopyDelimiters;
14 }
15
16 // Remove .katex-html blocks that are preceded by .katex-mathml blocks
17 // (which will get replaced below).
18 const katexHtml = fragment.querySelectorAll('.katex-mathml + .katex-html');
19
20 for (let i = 0; i < katexHtml.length; i++) {
21 const element = katexHtml[i];
22
23 if (element.remove) {
24 element.remove(null);
25 } else {
26 element.parentNode.removeChild(element);
27 }
28 } // Replace .katex-mathml elements with their annotation (TeX source)
29 // descendant, with inline delimiters.
30
31
32 const katexMathml = fragment.querySelectorAll('.katex-mathml');
33
34 for (let i = 0; i < katexMathml.length; i++) {
35 const element = katexMathml[i];
36 const texSource = element.querySelector('annotation');
37
38 if (texSource) {
39 if (element.replaceWith) {
40 element.replaceWith(texSource);
41 } else {
42 element.parentNode.replaceChild(texSource, element);
43 }
44
45 texSource.innerHTML = copyDelimiters.inline[0] + texSource.innerHTML + copyDelimiters.inline[1];
46 }
47 } // Switch display math to display delimiters.
48
49
50 const displays = fragment.querySelectorAll('.katex-display annotation');
51
52 for (let i = 0; i < displays.length; i++) {
53 const element = displays[i];
54 element.innerHTML = copyDelimiters.display[0] + element.innerHTML.substr(copyDelimiters.inline[0].length, element.innerHTML.length - copyDelimiters.inline[0].length - copyDelimiters.inline[1].length) + copyDelimiters.display[1];
55 }
56
57 return fragment;
58 };
59
60 document.addEventListener('copy', function (event) {
61 const selection = window.getSelection();
62
63 if (selection.isCollapsed) {
64 return; // default action OK if selection is empty
65 }
66
67 const fragment = selection.getRangeAt(0).cloneContents();
68
69 if (!fragment.querySelector('.katex-mathml')) {
70 return; // default action OK if no .katex-mathml elements
71 } // Preserve usual HTML copy/paste behavior.
72
73
74 const html = [];
75
76 for (let i = 0; i < fragment.childNodes.length; i++) {
77 html.push(fragment.childNodes[i].outerHTML);
78 }
79
80 event.clipboardData.setData('text/html', html.join('')); // Rewrite plain-text version.
81
82 event.clipboardData.setData('text/plain', katexReplaceWithTex(fragment).textContent); // Prevent normal copy handling.
83
84 event.preventDefault();
85 });