docs: special types

docs/docs/guides/domain-modeling.md

@@ -4,4 +4,80 @@ sidebar_position: 1
 
 # Domain modeling
 
-## Adding a blueprint
+## Adding a blueprint
+
+TODO
+
+
+
+## Special types
+When creating models, the user has to specify types. There are some types that needs special treatment.
+
+### `object` type
+The object type is used to specify that an attribute can be any object. 
+However, this should only be used as an `attributeType` inside a blueprint. Using it as `type` is not valid.
+For example, the following is NOT allowed:
+```json
+{
+  "type": "object",
+  "name": "objectEntity",
+  "description": "An entity of type object",
+  "numberValue": 1232,
+  "booleanValue": false,
+  "stringValue": "foo"
+}
+```
+
+
+
+Example usage of the object type: The FormBlueprint has an attribute called someEntity, and the entity of type FormBlueprint may 
+have any object value in its `someEntity` attribute. 
+
+
+```json
+{
+   "type": "dmss://system/SIMOS/Blueprint",
+   "name": "FormBlueprint",
+   "attributes": [
+      {
+        "attributeType": "string",
+        "type": "CORE:BlueprintAttribute",
+        "name": "type"
+      },
+      {
+        "attributeType": "string",
+        "type": "CORE:BlueprintAttribute",
+        "name": "name"
+      },
+      {
+        "type": "CORE:BlueprintAttribute",
+        "name": "someEntity",
+        "description": "Generic entity",
+        "attributeType": "object",
+        "contained": false
+      }
+   ]
+}
+````
+
+
+```json
+{
+   "type": "dmss://DemoDataSource/plugins/form/blueprints/FormBlueprint",
+   "name": "exampleForm",
+   "someEntity": {
+      "type": "dmss://DataSource/objectBlueprint",
+      "name": "objectEntity",
+      "numberValue": 1232,
+      "booleanValue": false
+    },
+   ...
+}
+````
+
+
+
+
+
+### `any` type
+The any type is another special type that should only be used internally in DMSS. Using it when modeling is not valid. This type is used in the `BlueprintAttribute` blueprint in DMSS, to make it possible for the `defaultValue` for a blueprint to have any type. Therefore, the `defaultValue` will not be validated in DMSS.