elk/composables/content.ts
2022-12-04 23:10:10 +01:00

201 lines
5.7 KiB
TypeScript

import type { Emoji } from 'masto'
import type { Node } from 'ultrahtml'
import { TEXT_NODE, parse, render, walkSync } from 'ultrahtml'
import type { VNode } from 'vue'
import { Fragment, h, isVNode } from 'vue'
import { RouterLink } from 'vue-router'
import ContentCode from '~/components/content/ContentCode.vue'
import AccountHoverWrapper from '~/components/account/AccountHoverWrapper.vue'
function handleMention(el: Node) {
// Redirect mentions to the user page
if (el.name === 'a' && el.attributes.class?.includes('mention')) {
const href = el.attributes.href
if (href) {
const matchUser = href.match(UserLinkRE)
if (matchUser) {
const [, server, username] = matchUser
const handle = `@${username}@${server.replace(/(.+\.)(.+\..+)/, '$2')}`
el.attributes.href = `/${server}/@${username}`
return h(AccountHoverWrapper, { handle, class: 'inline-block' }, () => nodeToVNode(el))
}
const matchTag = href.match(TagLinkRE)
if (matchTag) {
const [, , name] = matchTag
el.attributes.href = `/${currentServer.value}/tags/${name}`
}
}
}
return undefined
}
function handleCodeBlock(el: Node) {
if (el.name === 'pre' && el.children[0]?.name === 'code') {
const codeEl = el.children[0] as Node
const classes = codeEl.attributes.class as string
const lang = classes?.split(/\s/g).find(i => i.startsWith('language-'))?.replace('language-', '')
const code = codeEl.children[0] ? treeToText(codeEl.children[0]) : ''
return h(ContentCode, { lang, code: encodeURIComponent(code) })
}
}
function handleNode(el: Node) {
return handleCodeBlock(el) || handleMention(el) || el
}
/**
* Parse raw HTML form Mastodon server to AST,
* with interop of custom emojis and inline Markdown syntax
*/
export function parseMastodonHTML(html: string, customEmojis: Record<string, Emoji> = {}) {
let processed = html
// custom emojis
.replace(/:([\w-]+?):/g, (_, name) => {
const emoji = customEmojis[name]
if (emoji)
return `<img src="${emoji.url}" alt=":${name}:" class="custom-emoji" data-emoji-id="${name}" />`
return `:${name}:`
})
// handle code blocks
.replace(/>(```|~~~)(\w*)([\s\S]+?)\1/g, (_1, _2, lang, raw) => {
const code = htmlToText(raw)
const classes = lang ? ` class="language-${lang}"` : ''
return `><pre><code${classes}>${code}</code></pre>`
})
walkSync(parse(processed), (node) => {
if (node.type !== TEXT_NODE)
return
const replacements = [
[/\*\*\*(.*?)\*\*\*/g, '<b><em>$1</em></b>'],
[/\*\*(.*?)\*\*/g, '<b>$1</b>'],
[/\*(.*?)\*/g, '<em>$1</em>'],
[/~~(.*?)~~/g, '<del>$1</del>'],
[/`([^`]+?)`/g, '<code>$1</code>'],
] as const
for (const [re, replacement] of replacements) {
for (const match of node.value.matchAll(re)) {
if (node.loc) {
const start = match.index! + node.loc[0].start
const end = start + match[0].length + node.loc[0].start
processed = processed.slice(0, start) + match[0].replace(re, replacement) + processed.slice(end)
}
else {
processed = processed.replace(match[0], match[0].replace(re, replacement))
}
}
}
})
return parse(processed)
}
export async function convertMastodonHTML(html: string, customEmojis: Record<string, Emoji> = {}) {
const tree = parseMastodonHTML(html, customEmojis)
return await render(tree)
}
/**
* Raw HTML to VNodes
*/
export function contentToVNode(
content: string,
customEmojis: Record<string, Emoji> = {},
): VNode {
const tree = parseMastodonHTML(content, customEmojis)
return h(Fragment, (tree.children as Node[]).map(n => treeToVNode(n)))
}
function nodeToVNode(node: Node): VNode | string | null {
if (node.type === TEXT_NODE)
return node.value
if ('children' in node) {
if (node.name === 'a' && (node.attributes.href?.startsWith('/') || node.attributes.href?.startsWith('.'))) {
node.attributes.to = node.attributes.href
delete node.attributes.href
delete node.attributes.target
return h(
RouterLink as any,
node.attributes,
() => node.children.map(treeToVNode),
)
}
return h(
node.name,
node.attributes,
node.children.map(treeToVNode),
)
}
return null
}
function treeToVNode(
input: Node,
): VNode | string | null {
if (input.type === TEXT_NODE)
return input.value as string
if ('children' in input) {
const node = handleNode(input)
if (node == null)
return null
if (isVNode(node))
return node
return nodeToVNode(node)
}
return null
}
export function htmlToText(html: string) {
const tree = parse(html)
return (tree.children as Node[]).map(n => treeToText(n)).join('').trim()
}
export function treeToText(input: Node): string {
let pre = ''
let body = ''
let post = ''
if (input.type === TEXT_NODE)
return input.value
if (input.name === 'br')
return '\n'
if (['p', 'pre'].includes(input.name))
pre = '\n'
if (input.name === 'code') {
if (input.parent?.name === 'pre') {
const lang = input.attributes.class?.replace('language-', '')
pre = `\`\`\`${lang || ''}\n`
post = '\n```'
}
else {
pre = '`'
post = '`'
}
}
else if (input.name === 'b' || input.name === 'strong') {
pre = '**'
post = '**'
}
else if (input.name === 'i' || input.name === 'em') {
pre = '*'
post = '*'
}
else if (input.name === 'del') {
pre = '~~'
post = '~~'
}
if ('children' in input)
body = (input.children as Node[]).map(n => treeToText(n)).join('')
if (input.name === 'img' && input.attributes.class?.includes('custom-emoji'))
return `:${input.attributes['data-emoji-id']}:`
return pre + body + post
}