Added methods to revoke a users access to a list

models/error.go

@@ -530,3 +530,19 @@ func IsErrUserAlreadyHasAccess(err error) bool {
 func (err ErrUserAlreadyHasAccess) Error() string {
 	return fmt.Sprintf("This user already has access to that list. [User ID: %d, List ID: %d]", err.UserID, err.ListID)
 }
+
+// ErrUserDoesNotHaveAccessToList represents an error, where the user is not the owner of that List (used i.e. when deleting a List)
+type ErrUserDoesNotHaveAccessToList struct {
+	ListID int64
+	UserID int64
+}
+
+// IsErrUserDoesNotHaveAccessToList checks if an error is a ErrListDoesNotExist.
+func IsErrUserDoesNotHaveAccessToList(err error) bool {
+	_, ok := err.(ErrUserDoesNotHaveAccessToList)
+	return ok
+}
+
+func (err ErrUserDoesNotHaveAccessToList) Error() string {
+	return fmt.Sprintf("You need to have access to this List to do that [ListID: %d, UserID: %d]", err.ListID, err.UserID)
+}

models/list_users_delete.go

@@ -0,0 +1,25 @@
+package models
+
+// Delete deletes a list <-> user relation
+func (lu *ListUser) Delete() (err error) {
+
+	// Check if the user exists
+	_, _, err = GetUserByID(lu.UserID)
+	if err != nil {
+		return
+	}
+
+	// Check if the user has access to the list
+	has, err := x.Where("user_id = ? AND list_id = ?", lu.UserID, lu.ListID).
+		Get(&ListUser{})
+	if err != nil {
+		return
+	}
+	if !has {
+		return ErrUserDoesNotHaveAccessToList{ListID: lu.ListID, UserID: lu.UserID}
+	}
+
+	_, err = x.Where("user_id = ? AND list_id = ?", lu.UserID, lu.ListID).
+		Delete(&ListUser{})
+	return
+}

models/list_users_rights.go

@@ -32,3 +32,10 @@ func (lu *ListUser) CanCreate(doer *User) bool {
 	l, _ := GetListByID(lu.ListID)
 	return l.CanWrite(doer)
 }
+
+// CanDelete checks if the user can delete a user <-> list relation
+func (lu *ListUser) CanDelete(doer *User) bool {
+	// Get the list and check if the user has write access on it
+	l, _ := GetListByID(lu.ListID)
+	return l.CanWrite(doer)
+}