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authorHenry Jameson <me@hjkos.com>2022-03-16 21:00:20 +0200
committerHenry Jameson <me@hjkos.com>2022-03-16 21:00:20 +0200
commitcd4ad2df11369087b1f39bcaac1bbe258e00580d (patch)
treecb2131ccac2501587af7283e6ecd32d3d803e44e /src/services/html_converter/html_tree_converter.service.js
parent8a9115b58e020f750366e87bb4fd3483d6b62b03 (diff)
parentb632d740c13ff4e5c98a7a101f26ca60cd2629bb (diff)
Merge remote-tracking branch 'origin/develop' into vue3-again
* origin/develop: (475 commits) Apply 1 suggestion(s) to 1 file(s) Update dependency @ungap/event-target to v0.2.3 Update package.json fix broken icons after FA upgrade Update Font Awesome Update dependency webpack-dev-middleware to v3.7.3 Update dependency vuelidate to v0.7.7 Pin dependency @kazvmoe-infra/pinch-zoom-element to 1.2.0 lint Make media modal buttons larger Add English translation for hide tooltip Add hide button to media modal Lint Prevent hiding media viewer if swiped over SwipeClick Fix webkit image blurs Fix video in media modal not displaying properly Add changelog for https://git.pleroma.social/pleroma/pleroma-fe/-/merge_requests/1403 Remove image box-shadow in media modal Clean up debug code for image pinch zoom Bump @kazvmoe-infra/pinch-zoom-element to 1.2.0 on npm ...
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+import { getTagName } from './utility.service.js'
+import { unescape } from 'lodash'
+
+/**
+ * This is a not-so-tiny purpose-built HTML parser/processor. This parses html
+ * and converts it into a tree structure representing tag openers/closers and
+ * children.
+ *
+ * Structure follows this pattern: [opener, [...children], closer] except root
+ * node which is just [...children]. Text nodes can only be within children and
+ * are represented as strings.
+ *
+ * Intended use is to convert HTML structure and then recursively iterate over it
+ * most likely using a map. Very useful for dynamically rendering html replacing
+ * tags with JSX elements in a render function.
+ *
+ * known issue: doesn't handle CDATA so CDATA might not work well
+ * known issue: doesn't handle HTML comments
+ *
+ * @param {Object} input - input data
+ * @return {string} processed html
+ */
+export const convertHtmlToTree = (html = '') => {
+ // Elements that are implicitly self-closing
+ // https://developer.mozilla.org/en-US/docs/Glossary/empty_element
+ const emptyElements = new Set([
+ 'area', 'base', 'br', 'col', 'embed', 'hr', 'img', 'input',
+ 'keygen', 'link', 'meta', 'param', 'source', 'track', 'wbr'
+ ])
+ // TODO For future - also parse HTML5 multi-source components?
+
+ const buffer = [] // Current output buffer
+ const levels = [['', buffer]] // How deep we are in tags and which tags were there
+ let textBuffer = '' // Current line content
+ let tagBuffer = null // Current tag buffer, if null = we are not currently reading a tag
+
+ const getCurrentBuffer = () => {
+ return levels[levels.length - 1][1]
+ }
+
+ const flushText = () => { // Processes current line buffer, adds it to output buffer and clears line buffer
+ if (textBuffer === '') return
+ getCurrentBuffer().push(textBuffer)
+ textBuffer = ''
+ }
+
+ const handleSelfClosing = (tag) => {
+ getCurrentBuffer().push([tag])
+ }
+
+ const handleOpen = (tag) => {
+ const curBuf = getCurrentBuffer()
+ const newLevel = [unescape(tag), []]
+ levels.push(newLevel)
+ curBuf.push(newLevel)
+ }
+
+ const handleClose = (tag) => {
+ const currentTag = levels[levels.length - 1]
+ if (getTagName(levels[levels.length - 1][0]) === getTagName(tag)) {
+ currentTag.push(tag)
+ levels.pop()
+ } else {
+ getCurrentBuffer().push(tag)
+ }
+ }
+
+ for (let i = 0; i < html.length; i++) {
+ const char = html[i]
+ if (char === '<' && tagBuffer === null) {
+ flushText()
+ tagBuffer = char
+ } else if (char !== '>' && tagBuffer !== null) {
+ tagBuffer += char
+ } else if (char === '>' && tagBuffer !== null) {
+ tagBuffer += char
+ const tagFull = tagBuffer
+ tagBuffer = null
+ const tagName = getTagName(tagFull)
+ if (tagFull[1] === '/') {
+ handleClose(tagFull)
+ } else if (emptyElements.has(tagName) || tagFull[tagFull.length - 2] === '/') {
+ // self-closing
+ handleSelfClosing(tagFull)
+ } else {
+ handleOpen(tagFull)
+ }
+ } else {
+ textBuffer += char
+ }
+ }
+ if (tagBuffer) {
+ textBuffer += tagBuffer
+ }
+
+ flushText()
+ return buffer
+}