Add copy button to markdown code blocks (#17638)

* Add copy button to markdown code blocks

Done mostly in JS because I think it's better not to try getting buttons
past the markup sanitizer.

* add svg module tests

* fix sanitizer regexp

* remove outdated comment

* vertically center button in issue comments as well

* add comment to css

* fix undefined on view file line copy

* combine animation less files

* Update modules/markup/markdown/markdown.go

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

* add test for different sizes

* add cloneNode and add tests for it

* use deep clone

* remove useless optional chaining

* remove the svg node cache

* unify clipboard copy string and i18n

* remove unused var

* remove unused localization

* minor css tweaks to the button

* comment tweak

* remove useless attribute

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/js/features/clipboard.js

@@ -1,27 +1,25 @@
-// For all DOM elements with [data-clipboard-target] or [data-clipboard-text], this copy-to-clipboard will work for them
+const {copy_success, copy_error} = window.config.i18n;
 
-// TODO: replace these with toast-style notifications
 function onSuccess(btn) {
-  if (!btn.dataset.content) return;
+  btn.setAttribute('data-variation', 'inverted tiny');
   $(btn).popup('destroy');
-  const oldContent = btn.dataset.content;
-  btn.dataset.content = btn.dataset.success;
+  const oldContent = btn.getAttribute('data-content');
+  btn.setAttribute('data-content', copy_success);
   $(btn).popup('show');
-  btn.dataset.content = oldContent;
+  btn.setAttribute('data-content', oldContent || '');
 }
 function onError(btn) {
-  if (!btn.dataset.content) return;
-  const oldContent = btn.dataset.content;
+  btn.setAttribute('data-variation', 'inverted tiny');
+  const oldContent = btn.getAttribute('data-content');
   $(btn).popup('destroy');
-  btn.dataset.content = btn.dataset.error;
+  btn.setAttribute('data-content', copy_error);
   $(btn).popup('show');
-  btn.dataset.content = oldContent;
+  btn.setAttribute('data-content', oldContent || '');
 }
 
-/**
- * Fallback to use if navigator.clipboard doesn't exist.
- * Achieved via creating a temporary textarea element, selecting the text, and using document.execCommand.
- */
+
+// Fallback to use if navigator.clipboard doesn't exist. Achieved via creating
+// a temporary textarea element, selecting the text, and using document.execCommand
 function fallbackCopyToClipboard(text) {
   if (!document.execCommand) return false;
 
@@ -37,7 +35,8 @@ function fallbackCopyToClipboard(text) {
 
   tempTextArea.select();
 
-  // if unsecure (not https), there is no navigator.clipboard, but we can still use document.execCommand to copy to clipboard
+  // if unsecure (not https), there is no navigator.clipboard, but we can still
+  // use document.execCommand to copy to clipboard
   const success = document.execCommand('copy');
 
   document.body.removeChild(tempTextArea);
@@ -45,10 +44,13 @@ function fallbackCopyToClipboard(text) {
   return success;
 }
 
+// For all DOM elements with [data-clipboard-target] or [data-clipboard-text],
+// this copy-to-clipboard will work for them
 export default function initGlobalCopyToClipboardListener() {
   document.addEventListener('click', (e) => {
     let target = e.target;
-    // in case <button data-clipboard-text><svg></button>, so we just search up to 3 levels for performance.
+    // in case <button data-clipboard-text><svg></button>, so we just search
+    // up to 3 levels for performance
     for (let i = 0; i < 3 && target; i++) {
       let text;
       if (target.dataset.clipboardText) {

web_src/js/features/common-global.js

@@ -104,7 +104,7 @@ export function initGlobalCommon() {
   $('.ui.progress').progress({
     showActivity: false
   });
-  $('.poping.up').popup();
+  $('.poping.up').attr('data-variation', 'inverted tiny').popup();
   $('.top.menu .poping.up').popup({
     onShow() {
       if ($('.top.menu .menu.transition').hasClass('visible')) {

web_src/js/markup/codecopy.js

@@ -0,0 +1,16 @@
+import {svg} from '../svg.js';
+
+export function renderCodeCopy() {
+  const els = document.querySelectorAll('.markup .code-block code');
+  if (!els.length) return;
+
+  const button = document.createElement('button');
+  button.classList.add('code-copy', 'ui', 'button');
+  button.innerHTML = svg('octicon-copy');
+
+  for (const el of els) {
+    const btn = button.cloneNode(true);
+    btn.setAttribute('data-clipboard-text', el.textContent);
+    el.after(btn);
+  }
+}

web_src/js/markup/content.js

@@ -1,9 +1,11 @@
 import {renderMermaid} from './mermaid.js';
+import {renderCodeCopy} from './codecopy.js';
 import {initMarkupTasklist} from './tasklist.js';
 
 // code that runs for all markup content
 export function initMarkupContent() {
-  const _promise = renderMermaid(document.querySelectorAll('code.language-mermaid'));
+  renderMermaid();
+  renderCodeCopy();
 }
 
 // code that only runs for comments

web_src/js/markup/mermaid.js

@@ -8,8 +8,9 @@ function displayError(el, err) {
   el.closest('pre').before(errorNode);
 }
 
-export async function renderMermaid(els) {
-  if (!els || !els.length) return;
+export async function renderMermaid() {
+  const els = document.querySelectorAll('.markup code.language-mermaid');
+  if (!els.length) return;
 
   const {default: mermaid} = await import(/* webpackChunkName: "mermaid" */'mermaid');
 

web_src/js/svg.js

@@ -1,5 +1,6 @@
 import octiconChevronDown from '../../public/img/svg/octicon-chevron-down.svg';
 import octiconChevronRight from '../../public/img/svg/octicon-chevron-right.svg';
+import octiconCopy from '../../public/img/svg/octicon-copy.svg';
 import octiconGitMerge from '../../public/img/svg/octicon-git-merge.svg';
 import octiconGitPullRequest from '../../public/img/svg/octicon-git-pull-request.svg';
 import octiconIssueClosed from '../../public/img/svg/octicon-issue-closed.svg';
@@ -20,6 +21,7 @@ import Vue from 'vue';
 export const svgs = {
   'octicon-chevron-down': octiconChevronDown,
   'octicon-chevron-right': octiconChevronRight,
+  'octicon-copy': octiconCopy,
   'octicon-git-merge': octiconGitMerge,
   'octicon-git-pull-request': octiconGitPullRequest,
   'octicon-issue-closed': octiconIssueClosed,

web_src/js/svg.test.js

@@ -0,0 +1,7 @@
+import {svg} from './svg.js';
+
+test('svg', () => {
+  expect(svg('octicon-repo')).toStartWith('<svg');
+  expect(svg('octicon-repo', 16)).toInclude('width="16"');
+  expect(svg('octicon-repo', 32)).toInclude('width="32"');
+});