client/src/app/videos/shared/markdown.service.ts

   1 import { Injectable } from '@angular/core'
   2
   3 import * as MarkdownIt from 'markdown-it'
   4
   5 @Injectable()
   6 export class MarkdownService {
   7   private markdownIt: MarkdownIt.MarkdownIt
   8
   9   constructor () {
  10     this.markdownIt = new MarkdownIt('zero', { linkify: true })
  11       .enable('linkify')
  12       .enable('autolink')
  13       .enable('emphasis')
  14       .enable('link')
  15       .enable('newline')
  16
  17     // Snippet from markdown-it documentation: https://github.com/markdown-it/markdown-it/blob/master/docs/architecture.md#renderer
  18     const defaultRender = this.markdownIt.renderer.rules.link_open || function (tokens, idx, options, env, self) {
  19       return self.renderToken(tokens, idx, options)
  20     }
  21
  22     this.markdownIt.renderer.rules.link_open = function (tokens, idx, options, env, self) {
  23       // If you are sure other plugins can't add `target` - drop check below
  24       const aIndex = tokens[idx].attrIndex('target')
  25
  26       if (aIndex < 0) {
  27         tokens[idx].attrPush(['target', '_blank']) // add new attribute
  28       } else {
  29         tokens[idx].attrs[aIndex][1] = '_blank'    // replace value of existing attr
  30       }
  31
  32       // pass token to default renderer.
  33       return defaultRender(tokens, idx, options, env, self)
  34     }
  35   }
  36
  37   markdownToHTML (markdown: string) {
  38     const html = this.markdownIt.render(markdown)
  39
  40     // Avoid linkify truncated links
  41     return html.replace(/<a[^>]+>([^<]+)<\/a>\s*...(<\/p>)?$/mi, '$1...')
  42   }
  43 }