Add new hook to support unfollow contacts on non-native networks

doc/Addons.md

@@ -479,6 +479,23 @@ Hook data:
 - **uid** (input): the user to return the contact data for (can be empty for public contacts).
 - **result** (output): Set by the hook function to indicate a successful detection.
 
+### follow
+
+Called before adding a new contact for a user to handle non-native network remote contact (like Twitter).
+
+Hook data:
+
+- **url** (input): URL of the remote contact.
+- **contact** (output): should be filled with the contact (with uid = user creating the contact) array if follow was successful.
+
+### unfollow
+
+Called when unfollowing a remote contact on a non-native network (like Twitter)
+
+Hook data:
+- **contact** (input): the remote contact (uid = local unfollowing user id) array.
+- **dissolve** (input): whether to stop sharing with the remote contact as well.
+
 ## Complete list of hook callbacks
 
 Here is a complete list of all hook callbacks with file locations (as of 24-Sep-2018). Please see the source for details of any hooks not documented above.
@@ -648,6 +665,7 @@ Here is a complete list of all hook callbacks with file locations (as of 24-Sep-
 
     Hook::callAll('contact_photo_menu', $args);
     Hook::callAll('follow', $arr);
+    Hook::callAll('unfollow', $hook_data);
 
 ### src/Model/Profile.php
 

doc/de/Addons.md

@@ -356,6 +356,7 @@ Eine komplette Liste aller Hook-Callbacks mit den zugehörigen Dateien (am 01-Ap
 
     Hook::callAll('contact_photo_menu', $args);
     Hook::callAll('follow', $arr);
+    Hook::callAll('unfollow', $hook_data);
 
 ### src/Model/Profile.php
 

mod/unfollow.php

@@ -144,7 +144,7 @@ function unfollow_process(string $url)
 		Contact::terminateFriendship($owner, $contact, $dissolve);
 	}
 
-	// Sharing-only contacts get deleted as there no relationship any more
+	// Sharing-only contacts get deleted as there no relationship anymore
 	if ($dissolve) {
 		Contact::remove($contact['id']);
 		$return_path = $base_return_path;

src/Model/Contact.php

@@ -845,6 +845,12 @@ class Contact
 			if ($dissolve) {
 				ActivityPub\Transmitter::sendContactReject($contact['url'], $contact['hub-verify'], $user['uid']);
 			}
+		} else {
+			$hook_data = [
+				'contact' => $contact,
+				'dissolve' => $dissolve,
+			];
+			Hook::callAll('unfollow', $hook_data);
 		}
 	}