snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/public/model/channel_mentions.go

@@ -0,0 +1,96 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"regexp"
+	"strings"
+)
+
+var channelMentionRegexp = regexp.MustCompile(`\B~[a-zA-Z0-9\-_]+`)
+
+func ChannelMentions(message string) []string {
+	return ChannelMentionsFromStrings([]string{message})
+}
+
+// ChannelMentionsFromStrings extracts ~channel-name mentions from each string, deduplicating across
+// all inputs. Callers typically pass post.AllStrings() so mentions are found in the message, message
+// attachments, and interactive payloads (mm_blocks, blocks, cards) consistently with other post text.
+func ChannelMentionsFromStrings(strs []string) []string {
+	alreadyMentioned := make(map[string]bool)
+	var names []string
+
+	for _, s := range strs {
+		if !strings.Contains(s, "~") {
+			continue
+		}
+		for _, match := range channelMentionRegexp.FindAllString(s, -1) {
+			name := match[1:]
+			if !alreadyMentioned[name] {
+				names = append(names, name)
+				alreadyMentioned[name] = true
+			}
+		}
+	}
+
+	return names
+}
+
+// ChannelMentionsFromAttachments extracts channel mentions from attachment fields.
+// It scans pretext, text, and field values (but not titles, as titles are labels).
+func ChannelMentionsFromAttachments(attachments []*MessageAttachment) []string {
+	alreadyMentioned := make(map[string]bool)
+	var names []string
+
+	for _, attachment := range attachments {
+		if attachment == nil {
+			continue
+		}
+
+		// Scan pretext
+		for _, match := range channelMentionRegexp.FindAllString(attachment.Pretext, -1) {
+			name := match[1:]
+			if !alreadyMentioned[name] {
+				names = append(names, name)
+				alreadyMentioned[name] = true
+			}
+		}
+
+		// Scan text
+		for _, match := range channelMentionRegexp.FindAllString(attachment.Text, -1) {
+			name := match[1:]
+			if !alreadyMentioned[name] {
+				names = append(names, name)
+				alreadyMentioned[name] = true
+			}
+		}
+
+		// Scan field values (not titles - titles are labels)
+		for _, field := range attachment.Fields {
+			if field == nil {
+				continue
+			}
+
+			// Field value can be any type, convert to string
+			var valueStr string
+			switch v := field.Value.(type) {
+			case string:
+				valueStr = v
+			default:
+				// For non-string values, we don't scan for mentions
+				continue
+			}
+
+			for _, match := range channelMentionRegexp.FindAllString(valueStr, -1) {
+				name := match[1:]
+				if !alreadyMentioned[name] {
+					names = append(names, name)
+					alreadyMentioned[name] = true
+				}
+			}
+		}
+	}
+
+	return names
+}