Introduce "adding models" section to development docs

docs/development/adding-models.md

@@ -0,0 +1,85 @@
+# Adding Models
+
+## 1. Define the model class
+
+Models within each app are stored in either `models.py` or within a submodule under the `models/` directory. When creating a model, be sure to subclass the [appropriate base model](models.md) from `netbox.models`. This will typically be PrimaryModel or OrganizationalModel. Remember to add the model class to the `__all__` listing for the module.
+
+Each model should define, at a minimum:
+
+* A `__str__()` method returning a user-friendly string representation of the instance
+* A `get_absolute_url()` method returning an instance's direct URL (using `reverse()`)
+* A `Meta` class specifying a deterministic ordering (if ordered by fields other than the primary ID)
+
+## 2. Define field choices
+
+If the model has one or more fields with static choices, define those choices in `choices.py` by subclassing `utilities.choices.ChoiceSet`.
+
+## 3. Generate database migrations
+
+Once your model definition is complete, generate database migrations by running `manage.py -n $NAME --no-header`. Always specify a short unique name when generating migrations.
+
+!!! info
+    Set `DEVELOPER = True` in your NetBox configuration to enable the creation of new migrations.
+
+## 4. Add all standard views
+
+Most models will need view classes created in `views.py` to serve the following operations:
+
+* List view
+* Detail view
+* Edit view
+* Delete view
+* Bulk import
+* Bulk edit
+* Bulk delete
+
+## 5. Add URL paths
+
+Add the relevant URL path for each view created in the previous step to `urls.py`.
+
+## 6. Create the FilterSet
+
+Each model should have a corresponding FilterSet class defined. This is used to filter UI and API queries. Subclass the appropriate class from `netbox.filtersets` that matches the model's parent class.
+
+Every model FilterSet should define a `q` filter to support general search queries.
+
+## 7. Create the table
+
+Create a table class for the model in `tables.py` by subclassing `utilities.tables.BaseTable`. Under the table's `Meta` class, be sure to list both the fields and default columns.
+
+## 8. Create the object template
+
+Create the HTML template for the object view. (The other views each typically employ a generic template.) This template should extend `generic/object.html`.
+
+## 9. Add the model to the navigation menu
+
+For NetBox releases prior to v3.0, add the relevant link(s) to the navigation menu template. For later releases, add the relevant items in `netbox/netbox/navigation_menu.py`.
+
+## 10. REST API components
+
+Create the following for each model:
+
+* Detailed (full) model serializer in `api/serializers.py`
+* Nested serializer in `api/nested_serializers.py`
+* API view in `api/views.py`
+* Endpoint route in `api/urls.py`
+
+## 11. GraphQL API components (v3.0+)
+
+Create a Graphene object type for the model in `graphql/types.py` by subclassing the appropriate class from `netbox.graphql.types`.
+
+Also extend the schema class defined in `graphql/schema.py` with the individual object and object list fields per the established convention.
+
+## 12. Add tests
+
+Add tests for the following:
+
+* UI views
+* API views
+* Filter sets
+
+## 13. Documentation
+
+Create a new documentation page for the model in `docs/models/<app_label>/<model_name>.md`. Include this file under the "features" documentation where appropriate.
+
+Also add your model to the index in `docs/development/models.md`.

mkdocs.yml

@@ -76,6 +76,7 @@ nav:
         - Getting Started: 'development/getting-started.md'
         - Style Guide: 'development/style-guide.md'
         - Models: 'development/models.md'
+        - Adding Models: 'development/adding-models.md'
         - Extending Models: 'development/extending-models.md'
         - Application Registry: 'development/application-registry.md'
         - User Preferences: 'development/user-preferences.md'