property value as Union type

lib/membership/property.ex

@@ -16,8 +16,16 @@ defmodule Mv.Membership.Property do
   attributes do
     uuid_primary_key :id
 
-    attribute :value, :string,
-      description: "Speichert den Wert, Typ-Interpretation per property_type.typ"
+    attribute :value, :union,
+      constraints: [
+        storage: :type_and_value,
+        types: [
+          boolean: [type: :boolean],
+          date: [type: :date],
+          integer: [type: :integer],
+          string: [type: :string]
+        ]
+      ]
   end
 
   relationships do
@@ -25,4 +33,8 @@ defmodule Mv.Membership.Property do
 
     belongs_to :property_type, Mv.Membership.PropertyType
   end
+
+  calculations do
+    calculate :value_to_string, :string, expr(value[:value] <> "")
+  end
 end

lib/membership/property_type.ex

@@ -10,7 +10,7 @@ defmodule Mv.Membership.PropertyType do
 
   actions do
     defaults [:create, :read, :update, :destroy]
-    default_accept [:name, :type, :description, :immutable, :required]
+    default_accept [:name, :value_type, :description, :immutable, :required]
   end
 
   attributes do
@@ -18,7 +18,8 @@ defmodule Mv.Membership.PropertyType do
 
     attribute :name, :string, allow_nil?: false, public?: true
 
-    attribute :type, :string,
+    attribute :value_type, :atom,
+      constraints: [one_of: [:string, :integer, :boolean, :date]],
       allow_nil?: false,
       description: "Definies the datatype `Property.value` is interpreted as"