FIX: Permalink.create didn't work as expected anymore (#29895)

This moves the logic of setting the correct permalink values back into the controller. And it replaces the validation with a simpler one, that always works, even when the model is loaded from the DB.

Follow-up to #29634 which broke import scripts and lots of documentation on Meta.

app/assets/javascripts/admin/addon/components/admin-permalink-form.gjs

@@ -45,7 +45,7 @@ export default class AdminFlagsForm extends Component {
       } else if (!isEmpty(this.args.permalink.category_id)) {
         permalinkType = "category";
         permalinkValue = this.args.permalink.category_id;
-      } else if (!isEmpty(this.args.permalink.tag_name)) {
+      } else if (!isEmpty(this.args.permalink.tag_id)) {
         permalinkType = "tag";
         permalinkValue = this.args.permalink.tag_name;
       } else if (!isEmpty(this.args.permalink.external_url)) {

app/controllers/admin/permalinks_controller.rb

@@ -20,24 +20,14 @@ class Admin::PermalinksController < Admin::AdminController
   end
 
   def create
-    permalink =
-      Permalink.create!(
-        url: permalink_params[:url],
-        permalink_type: permalink_params[:permalink_type],
-        permalink_type_value: permalink_params[:permalink_type_value],
-      )
+    permalink = Permalink.create!(permalink_params)
     render_serialized(permalink, PermalinkSerializer)
   rescue ActiveRecord::RecordInvalid => e
     render_json_error(e.record.errors.full_messages)
   end
 
   def update
-    @permalink.update!(
-      url: permalink_params[:url],
-      permalink_type: permalink_params[:permalink_type],
-      permalink_type_value: permalink_params[:permalink_type_value],
-    )
-
+    @permalink.update!(permalink_params)
     render_serialized(@permalink, PermalinkSerializer)
   rescue ActiveRecord::RecordInvalid => e
     render_json_error(e.record.errors.full_messages)
@@ -55,6 +45,24 @@ class Admin::PermalinksController < Admin::AdminController
   end
 
   def permalink_params
-    params.require(:permalink).permit(:url, :permalink_type, :permalink_type_value)
+    permitted_params =
+      params.require(:permalink).permit(:url, :permalink_type, :permalink_type_value)
+
+    {
+      url: permitted_params[:url],
+      topic_id: extract_param(permitted_params, "topic"),
+      post_id: extract_param(permitted_params, "post"),
+      category_id: extract_param(permitted_params, "category"),
+      tag_id:
+        extract_param(permitted_params, "tag").then do |tag_name|
+          (Tag.where(name: tag_name).pluck(:id).first || -1) if tag_name
+        end,
+      user_id: extract_param(permitted_params, "user"),
+      external_url: extract_param(permitted_params, "external_url"),
+    }
+  end
+
+  def extract_param(permitted_params, type)
+    permitted_params[:permalink_type] == type ? permitted_params[:permalink_type_value] : nil
   end
 end

app/models/permalink.rb

@@ -1,30 +1,16 @@
 # frozen_string_literal: true
 
 class Permalink < ActiveRecord::Base
-  attr_accessor :permalink_type, :permalink_type_value
-
   belongs_to :topic
   belongs_to :post
   belongs_to :category
   belongs_to :tag
   belongs_to :user
 
-  before_validation :clear_associations
   before_validation :normalize_url, :encode_url
-  before_validation :set_association_value
 
   validates :url, uniqueness: true
-
-  validates :topic_id, presence: true, if: Proc.new { |permalink| permalink.topic_type? }
-  validates :post_id, presence: true, if: Proc.new { |permalink| permalink.post_type? }
-  validates :category_id, presence: true, if: Proc.new { |permalink| permalink.category_type? }
-  validates :tag_id, presence: true, if: Proc.new { |permalink| permalink.tag_type? }
-  validates :user_id, presence: true, if: Proc.new { |permalink| permalink.user_type? }
-  validates :external_url, presence: true, if: Proc.new { |permalink| permalink.external_url_type? }
-
-  %i[topic post category tag user external_url].each do |association|
-    define_method("#{association}_type?") { self.permalink_type == association.to_s }
-  end
+  validate :exactly_one_association
 
   class Normalizer
     attr_reader :source
@@ -114,22 +100,14 @@ class Permalink < ActiveRecord::Base
     external_url.match?(%r{\A/[^/]}) ? "#{Discourse.base_path}#{external_url}" : external_url
   end
 
-  def clear_associations
-    self.topic_id = nil
-    self.post_id = nil
-    self.category_id = nil
-    self.user_id = nil
-    self.tag_id = nil
-    self.external_url = nil
-  end
-
-  def set_association_value
-    self.topic_id = self.permalink_type_value if self.topic_type?
-    self.post_id = self.permalink_type_value if self.post_type?
-    self.user_id = self.permalink_type_value if self.user_type?
-    self.category_id = self.permalink_type_value if self.category_type?
-    self.external_url = self.permalink_type_value if self.external_url_type?
-    self.tag_id = Tag.where(name: self.permalink_type_value).first&.id if self.tag_type?
+  def exactly_one_association
+    associations = [topic_id, post_id, category_id, tag_id, user_id, external_url]
+    if associations.compact.size != 1
+      errors.add(
+        :base,
+        "Exactly one of topic_id, post_id, category_id, tag_id, user_id, or external_url must be set",
+      )
+    end
   end
 end