Add markdown support to video description

1 files changed, 40 insertions, 0 deletions

diff --git a/client/src/app/videos/shared/markdown.service.ts b/client/src/app/videos/shared/markdown.service.ts
new file mode 100644
index 000000000..d8b5b76b6
--- /dev/null
+++ b/client/src/app/videos/shared/markdown.service.ts
@@ -0,0 +1,40 @@
+import { Injectable } from '@angular/core'
+
+import * as MarkdownIt from 'markdown-it'
+
+@Injectable()
+export class MarkdownService {
+  private markdownIt: MarkdownIt.MarkdownIt
+
+  constructor () {
+    this.markdownIt = new MarkdownIt('zero', { linkify: true })
+      .enable('linkify')
+      .enable('autolink')
+      .enable('emphasis')
+      .enable('link')
+      .enable('newline')
+
+    // Snippet from markdown-it documentation: https://github.com/markdown-it/markdown-it/blob/master/docs/architecture.md#renderer
+    const defaultRender = this.markdownIt.renderer.rules.link_open || function (tokens, idx, options, env, self) {
+      return self.renderToken(tokens, idx, options)
+    }
+
+    this.markdownIt.renderer.rules.link_open = function (tokens, idx, options, env, self) {
+      // If you are sure other plugins can't add `target` - drop check below
+      const aIndex = tokens[idx].attrIndex('target')
+
+      if (aIndex < 0) {
+        tokens[idx].attrPush(['target', '_blank']) // add new attribute
+      } else {
+        tokens[idx].attrs[aIndex][1] = '_blank'    // replace value of existing attr
+      }
+
+      // pass token to default renderer.
+      return defaultRender(tokens, idx, options, env, self)
+    }
+  }
+
+  markdownToHTML (markdown: string) {
+    return this.markdownIt.render(markdown)
+  }
+}