Extract the logic for tags that need message-tags to its own type.

include/modules/ctctags.h

@@ -27,6 +27,7 @@ namespace CTCTags
 	class EventListener;
 	class TagMessage;
 	class TagMessageDetails;
+	class TagProvider;
 }
 
 class CTCTags::CapReference final
@@ -163,3 +164,26 @@ public:
 	 */
 	virtual void OnUserTagMessageBlocked(User* user, const MessageTarget& target, const TagMessageDetails& details) { }
 };
+
+class CTCTags::TagProvider
+	: public ClientProtocol::MessageTagProvider
+{
+private:
+	CapReference ctctagcap;
+
+public:
+	TagProvider(Module* mod)
+		: ClientProtocol::MessageTagProvider(mod)
+		, ctctagcap(mod)
+	{
+	}
+
+	/** Retrieves the underlying message-tags capability. */
+	const CapReference& GetCap() const  { return ctctagcap; }
+
+	/** @copydoc ClientProtocol::MessageTagProvider::ShouldSendTag */
+	bool ShouldSendTag(LocalUser* user, const ClientProtocol::MessageTagData& tagdata) override
+	{
+		return ctctagcap.IsEnabled(user);
+	}
+};

src/modules/m_botmode.cpp

@@ -30,17 +30,15 @@
 #include "modules/whois.h"
 
 class BotTag final
-	: public ClientProtocol::MessageTagProvider
+	: public CTCTags::TagProvider
 {
 private:
 	SimpleUserMode& botmode;
-	CTCTags::CapReference ctctagcap;
 
 public:
 	BotTag(Module* mod, SimpleUserMode& bm)
-		: ClientProtocol::MessageTagProvider(mod)
+		: CTCTags::TagProvider(mod)
 		, botmode(bm)
-		, ctctagcap(mod)
 	{
 	}
 
@@ -50,11 +48,6 @@ public:
 		if (user && user->IsModeSet(botmode))
 			msg.AddTag("bot", this, "");
 	}
-
-	bool ShouldSendTag(LocalUser* user, const ClientProtocol::MessageTagData& tagdata) override
-	{
-		return ctctagcap.IsEnabled(user);
-	}
 };
 
 class ModuleBotMode final

src/modules/m_ircv3_msgid.cpp

@@ -21,15 +21,11 @@
 #include "modules/ctctags.h"
 
 class MsgIdTag final
-	: public ClientProtocol::MessageTagProvider
+	: public CTCTags::TagProvider
 {
-private:
-	CTCTags::CapReference ctctagcap;
-
 public:
 	MsgIdTag(Module* mod)
-		: ClientProtocol::MessageTagProvider(mod)
-		, ctctagcap(mod)
+		: CTCTags::TagProvider(mod)
 	{
 	}
 
@@ -41,11 +37,6 @@ public:
 		// We should only allow this tag if it is added by a remote server.
 		return IS_LOCAL(user) ? MOD_RES_DENY : MOD_RES_ALLOW;
 	}
-
-	bool ShouldSendTag(LocalUser* user, const ClientProtocol::MessageTagData& tagdata) override
-	{
-		return ctctagcap.IsEnabled(user);
-	}
 };
 
 class MsgIdGenerator final

src/modules/m_spanningtree/tags.cpp

@@ -40,8 +40,7 @@ bool ServerTags::ShouldSendTag(LocalUser* user, const ClientProtocol::MessageTag
 }
 
 ServiceTag::ServiceTag(Module* mod)
-	: ClientProtocol::MessageTagProvider(mod)
-	, ctctagcap(mod)
+	: CTCTags::TagProvider(mod)
 {
 }
 
@@ -51,8 +50,3 @@ void ServiceTag::OnPopulateTags(ClientProtocol::Message& msg)
 	if (user && user->server->IsService())
 		msg.AddTag("inspircd.org/service", this, "");
 }
-
-bool ServiceTag::ShouldSendTag(LocalUser* user, const ClientProtocol::MessageTagData& tagdata)
-{
-	return ctctagcap.IsEnabled(user);
-}

src/modules/m_spanningtree/tags.h

@@ -22,7 +22,7 @@
 #include "modules/ctctags.h"
 
 class ServerTags final
-    : public ClientProtocol::MessageTagProvider
+	: public ClientProtocol::MessageTagProvider
 {
 public:
 	ServerTags(Module* Creator);
@@ -31,13 +31,9 @@ public:
 };
 
 class ServiceTag final
-    : public ClientProtocol::MessageTagProvider
+	: public CTCTags::TagProvider
 {
-private:
-	CTCTags::CapReference ctctagcap;
-
 public:
 	ServiceTag(Module* mod);
 	void OnPopulateTags(ClientProtocol::Message& msg) override;
-	bool ShouldSendTag(LocalUser* user, const ClientProtocol::MessageTagData& tagdata) override;
 };