MDL-65093 core_message: users can't block any user they want

If blocking will have no effect (ie. you are attempting to block
the admin) the 'Block' button will not be shown and instead a
message will be shown explaining why you can not block the user.

lang/en/message.php

@@ -39,6 +39,7 @@
 $string['blockuserconfirmbutton'] = 'Block';
 $string['blocknoncontacts'] = 'Prevent non-contacts from messaging me';
 $string['cancelselection'] = 'Cancel message selection';
+$string['cantblockuser'] = 'You are unable to block {$a} because they have a role with permission to message all users';
 $string['contactableprivacy'] = 'Accept messages from:';
 $string['contactableprivacy_onlycontacts'] = 'My contacts only';
 $string['contactableprivacy_coursemember'] = 'My contacts and anyone in my courses';

message/amd/src/message_drawer_view_conversation.js

@@ -182,7 +182,8 @@ function(
             isblocked: null,
             iscontact: null,
             isdeleted: null,
-            canmessage:  null,
+            canmessage: null,
+            canmessageevenifblocked: null,
             requirescontact: null,
             contactrequests: []
         };

message/amd/src/message_drawer_view_conversation_renderer.js

@@ -1069,10 +1069,17 @@ function(
      */
     var renderConfirmBlockUser = function(header, body, footer, user) {
         if (user) {
-            return Str.get_string('blockuserconfirm', 'core_message', user.fullname)
-                .then(function(string) {
-                    return showConfirmDialogue(header, body, footer, [SELECTORS.ACTION_CONFIRM_BLOCK], string, '', true, false);
-                });
+            if (user.canmessageevenifblocked) {
+                return Str.get_string('cantblockuser', 'core_message', user.fullname)
+                    .then(function(string) {
+                        return showConfirmDialogue(header, body, footer, [], string, '', true, false);
+                    });
+            } else {
+                return Str.get_string('blockuserconfirm', 'core_message', user.fullname)
+                    .then(function(string) {
+                        return showConfirmDialogue(header, body, footer, [SELECTORS.ACTION_CONFIRM_BLOCK], string, '', true, false);
+                    });
+            }
         } else {
             return hideConfirmDialogue(header, body, footer);
         }

message/amd/src/message_drawer_view_conversation_state_manager.js

@@ -88,7 +88,8 @@ define(['jquery'], function($) {
                 isblocked: member.isblocked,
                 iscontact: member.iscontact,
                 isdeleted: member.isdeleted,
-                canmessage:  member.canmessage,
+                canmessage: member.canmessage,
+                canmessageevenifblocked: member.canmessageevenifblocked,
                 requirescontact: member.requirescontact,
                 contactrequests: member.contactrequests || []
             };

message/classes/api.php

@@ -1869,9 +1869,11 @@ public static function can_post_message($recipient, $sender = null) {
      *
      * @param int $recipientid The recipient user id.
      * @param int $senderid The sender user id.
+     * @param bool $evenifblocked This lets the user know, that even if the recipient has blocked the user
+     *        the user is still able to send a message.
      * @return bool true if user is permitted, false otherwise.
      */
-    public static function can_send_message(int $recipientid, int $senderid) : bool {
+    public static function can_send_message(int $recipientid, int $senderid, bool $evenifblocked = false) : bool {
         $systemcontext = \context_system::instance();
 
         if (!has_capability('moodle/site:sendmessage', $systemcontext, $senderid)) {
@@ -1883,7 +1885,7 @@ public static function can_send_message(int $recipientid, int $senderid) : bool
         }
 
         // Check if the recipient can be messaged by the sender.
-        return self::can_contact_user($recipientid, $senderid);
+        return self::can_contact_user($recipientid, $senderid, $evenifblocked);
     }
 
     /**
@@ -2966,9 +2968,11 @@ public static function is_user_in_conversation(int $userid, int $conversationid)
      *
      * @param int $recipientid
      * @param int $senderid
+     * @param bool $evenifblocked This lets the user know, that even if the recipient has blocked the user
+     *        the user is still able to send a message.
      * @return bool true if recipient hasn't blocked sender and sender can contact to recipient, false otherwise.
      */
-    protected static function can_contact_user(int $recipientid, int $senderid) : bool {
+    protected static function can_contact_user(int $recipientid, int $senderid, bool $evenifblocked = false) : bool {
         if (has_capability('moodle/site:messageanyuser', \context_system::instance(), $senderid) ||
             $recipientid == $senderid) {
             // The sender has the ability to contact any user across the entire site or themselves.
@@ -2978,7 +2982,7 @@ protected static function can_contact_user(int $recipientid, int $senderid) : bo
         // The initial value of $cancontact is null to indicate that a value has not been determined.
         $cancontact = null;
 
-        if (self::is_blocked($recipientid, $senderid)) {
+        if (self::is_blocked($recipientid, $senderid) || $evenifblocked) {
             // The recipient has specifically blocked this sender.
             $cancontact = false;
         }