Add wildcard_url validation to page model

To ease the complexity of the page_finder it is required, that the parameter key is unique for all page layouts. This requirement is reducing the searching complexity and also prevent edge cases where different page_layouts in the same tree can have multiple times the same parameter name (e.g. :id).

Author: kulturbande

app/models/alchemy/page/page_naming.rb

@@ -20,6 +20,7 @@ module PageNaming
         validates :urlname,
           uniqueness: {scope: [:language_id, :layoutpage], if: -> { urlname.present? }, case_sensitive: false},
           exclusion: {in: RESERVED_URLNAMES}
+        validate :unique_wildcard_param_keys, if: :has_wildcard_url?
 
         after_update :update_descendants_urlnames,
           if: :saved_change_to_urlname?
@@ -55,6 +56,21 @@ def has_wildcard_url?
 
       private
 
+      def unique_wildcard_param_keys
+        conflicting = PageDefinition.all.find do |other|
+          other.name != page_layout && other.wildcard_url == wildcard_url
+        end
+
+        if conflicting
+          errors.add(
+            :page_layout,
+            :conflicting_wildcard_param_key,
+            param: wildcard_url,
+            conflicting_layout: conflicting.name
+          )
+        end
+      end
+
       def update_descendants_urlnames
         reload
         descendants.each(&:update_urlname!)

config/locales/alchemy.en.yml

@@ -834,6 +834,8 @@ en:
             base:
               restrict_dependent_destroy:
                 has_many: "There are still %{record} attached to this page. Please remove them first."
+            page_layout:
+              conflicting_wildcard_param_key: "has a conflicting wildcard param \"%{param}\" already used by the \"%{conflicting_layout}\" page layout"
             descendants:
               still_attached_to_nodes: "The following descendant pages are still attached to menu nodes: %{page_names}. Please remove them first."
         alchemy/element:

spec/models/alchemy/page_spec.rb

@@ -1933,6 +1933,38 @@ module Alchemy
         end
       end
 
+      context "with conflicting wildcard param keys across layouts" do
+        let(:parent) { create(:alchemy_page, name: "Items") }
+
+        before do
+          PageDefinition.add(
+            name: "conflicting_layout",
+            wildcard_url: ":slug"
+          )
+        end
+
+        after { PageDefinition.reset! }
+
+        it "is invalid when another layout already uses the same param key" do
+          page = build(:alchemy_page, parent: parent, name: "Item", page_layout: "conflicting_layout")
+          expect(page).not_to be_valid
+          expect(page.errors[:page_layout]).to include(
+            a_string_matching(/param ":slug".*"page_with_wildcard_url"/)
+          )
+        end
+      end
+
+      context "with the same wildcard layout under different parents" do
+        let(:parent_a) { create(:alchemy_page, name: "Section A") }
+        let(:parent_b) { create(:alchemy_page, name: "Section B") }
+
+        it "allows creating pages with the same layout" do
+          create(:alchemy_page, parent: parent_a, name: "Detail A", page_layout: "page_with_wildcard_url")
+          page_b = build(:alchemy_page, parent: parent_b, name: "Detail B", page_layout: "page_with_wildcard_url")
+          expect(page_b).to be_valid
+        end
+      end
+
       context "if new urlname exists as a legacy url" do
         it "will delete obsolete legacy_urls" do
           expect(page.urlname).to eq("parentparent/parent/page")