docs/models-services.md

@@ -16,6 +16,8 @@ A service takes (in most cases) a model and returns one.
   * [Before Request](#before-request)
   * [After Request?](#after-request-)
 * [Models](#models)
+  * [Default Values](#default-values)
+  * [Constructor](#constructor)
 
 ## Services
 
@@ -104,3 +106,65 @@ Processing raw api data should be done in the constructor of the model, see more
 
 ## Models
 
+Models are a bit simpler than services.
+They usually consist of a declaration of defaults and an optional constructor.
+
+Models are located in `src/models`.
+
+Each model should extend the `AbstractModel`.
+This handles the default value parsing.
+
+A model _does not_ handle any http requests, that's what services are for.
+
+A simple model can look like this:
+
+```javascript
+import AbstractModel from './abstractModel'
+import TaskModel from './task'
+import UserModel from './user'
+
+export default class ListModel extends AbstractModel {
+	
+	constructor(data) {
+		// The constructor of AbstractModel handles all the default parsing.
+		super(data)
+		
+		// Make all tasks to task models
+		this.tasks = this.tasks.map(t => {
+			return new TaskModel(t)
+		})
+		
+		this.owner = new UserModel(this.owner)
+	}
+	
+	// Default attributes that define the "empty" state.
+	defaults() {
+		return {
+			id: 0,
+			title: '',
+			description: '',
+			owner: UserModel,
+			tasks: [],
+			namespaceID: 0,
+			
+			created: 0,
+			updated: 0,
+		}
+	}
+}
+```
+
+#### Default values
+
+The `defaults()` functions provides all default values.
+The `AbstractModel` constructor will take all the data provided to it, and fill any non-existent,
+`undefined` or `null` value with the default provided by the function.
+
+#### Constructor
+
+The `AbstractModel` constructor handles all the default value parsing.
+In your model, the constructor can do additional parsing, like making js date object from unix timestamps
+or parsing the contents of a child-array into a model.
+
+If the model does nothing like this, you don't need to define a constructor at all.
+The parent will handle it all.