| // Set these to how you want inline and display math to be delimited. |
| const defaultCopyDelimiters = { |
| inline: ['$', '$'], |
| // alternative: ['\(', '\)'] |
| display: ['$$', '$$'] // alternative: ['\[', '\]'] |
| |
| }; // Replace .katex elements with their TeX source (<annotation> element). |
| // Modifies fragment in-place. Useful for writing your own 'copy' handler, |
| // as in copy-tex.js. |
| |
| const katexReplaceWithTex = function katexReplaceWithTex(fragment, copyDelimiters) { |
| if (copyDelimiters === void 0) { |
| copyDelimiters = defaultCopyDelimiters; |
| } |
| |
| // Remove .katex-html blocks that are preceded by .katex-mathml blocks |
| // (which will get replaced below). |
| const katexHtml = fragment.querySelectorAll('.katex-mathml + .katex-html'); |
| |
| for (let i = 0; i < katexHtml.length; i++) { |
| const element = katexHtml[i]; |
| |
| if (element.remove) { |
| element.remove(null); |
| } else { |
| element.parentNode.removeChild(element); |
| } |
| } // Replace .katex-mathml elements with their annotation (TeX source) |
| // descendant, with inline delimiters. |
| |
| |
| const katexMathml = fragment.querySelectorAll('.katex-mathml'); |
| |
| for (let i = 0; i < katexMathml.length; i++) { |
| const element = katexMathml[i]; |
| const texSource = element.querySelector('annotation'); |
| |
| if (texSource) { |
| if (element.replaceWith) { |
| element.replaceWith(texSource); |
| } else { |
| element.parentNode.replaceChild(texSource, element); |
| } |
| |
| texSource.innerHTML = copyDelimiters.inline[0] + texSource.innerHTML + copyDelimiters.inline[1]; |
| } |
| } // Switch display math to display delimiters. |
| |
| |
| const displays = fragment.querySelectorAll('.katex-display annotation'); |
| |
| for (let i = 0; i < displays.length; i++) { |
| const element = displays[i]; |
| 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]; |
| } |
| |
| return fragment; |
| }; |
| |
| document.addEventListener('copy', function (event) { |
| const selection = window.getSelection(); |
| |
| if (selection.isCollapsed) { |
| return; // default action OK if selection is empty |
| } |
| |
| const fragment = selection.getRangeAt(0).cloneContents(); |
| |
| if (!fragment.querySelector('.katex-mathml')) { |
| return; // default action OK if no .katex-mathml elements |
| } // Preserve usual HTML copy/paste behavior. |
| |
| |
| const html = []; |
| |
| for (let i = 0; i < fragment.childNodes.length; i++) { |
| html.push(fragment.childNodes[i].outerHTML); |
| } |
| |
| event.clipboardData.setData('text/html', html.join('')); // Rewrite plain-text version. |
| |
| event.clipboardData.setData('text/plain', katexReplaceWithTex(fragment).textContent); // Prevent normal copy handling. |
| |
| event.preventDefault(); |
| }); |