YouTube link embeds

pkg/expand_media.go

@@ -0,0 +1,29 @@
+package barertc
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// Media regexps
+var (
+	ytLinkRegexp = regexp.MustCompile(`(?:youtube(?:-nocookie)?\.com/(?:[^/]+/.+/|(?:v|e(?:mbed)?)/|.*[?&]v=)|youtu\.be/)([^"&?/\s]{11})`)
+	ytIdRegexp   = regexp.MustCompile(`[0-9A-Za-z_-]{10}[048AEIMQUYcgkosw]`) // YT ID validator
+)
+
+// YT embed template
+const youtubeEmbedTemplate = `<iframe class="youtube-embed" width="560" height="315" src="https://www.youtube.com/embed/%s" title="YouTube video player" frameborder="0" allow="autoplay; encrypted-media; picture-in-picture; web-share" allowfullscreen></iframe>`
+
+// ExpandMedia detects media URLs such as YouTube videos and stylizes the message up with embeds.
+func (s *Server) ExpandMedia(message string) string {
+	// YouTube links.
+	if m := ytLinkRegexp.FindStringSubmatch(message); len(m) > 0 {
+		var ytid = m[1]
+
+		// Sanity check the ID parsed OK (e.g. multiple youtube links can throw it off)
+		if ytIdRegexp.Match([]byte(ytid)) {
+			message += fmt.Sprintf(youtubeEmbedTemplate, ytid)
+		}
+	}
+	return message
+}

pkg/handlers.go

@@ -120,6 +120,9 @@ func (s *Server) OnMessage(sub *Subscriber, msg Message) {
 		return
 	}
 
+	// Detect and expand media such as YouTube videos.
+	markdown = s.ExpandMedia(markdown)
+
 	// Message to be echoed to the channel.
 	var message = Message{
 		Action:   ActionMessage,

web/static/css/chat.css

@@ -238,3 +238,8 @@ body {
     font-size: small;
     padding: 2px 4px;
 }
+
+/* YouTube embeds */
+.youtube-embed {
+    max-width: 100%;
+}