Merge branch 'develop' into develop-2.5

docs/development/extending-models.md

@@ -0,0 +1,70 @@
+# Extending Models
+
+Below is a list of items to consider when adding a new field to a model:
+
+### 1. Generate and run database migration
+
+Django migrations are used to express changes to the database schema. In most cases, Django can generate these automatically, however very complex changes may require manual intervention. Always remember to specify a short but descriptive name when generating a new migration.
+
+```
+./manage.py makemigrations <app> -n <name>
+./manage.py migrate
+```
+
+Where possible, try to merge related changes into a single migration. For example, if three new fields are being added to different models within an app, these can be expressed in the same migration. You can merge a new migration with an existing one by combining their `operations` lists.
+
+!!! note
+    Migrations can only be merged within a release. Once a new release has been published, its migrations cannot be altered.
+
+### 2. Add validation logic to `clean()`
+
+If the new field introduces additional validation requirements (beyond what's included with the field itself), implement them in the model's `clean()` method. Remember to call the model's original method using `super()` before or agter your custom validation as appropriate:
+
+```
+class Foo(models.Model):
+
+    def clean(self):
+
+        super(DeviceCSVForm, self).clean()
+
+        # Custom validation goes here
+        if self.bar is None:
+            raise ValidationError()
+```
+
+### 3. Add CSV helpers
+
+Add the name of the new field to `csv_headers` and included a CSV-friendly representation of its data in the model's `to_csv()` method. These will be used when exporting objects in CSV format.
+
+### 4. Update relevant querysets
+
+If you're adding a relational field (e.g. `ForeignKey`) and intend to include the data when retreiving a list of objects, be sure to include the field using `select_related()` or `prefetch_related()` as appropriate. This will optimize the view and avoid excessive database lookups.
+
+### 5. Update API serializer
+
+Extend the model's API serializer in `<app>.api.serializers` to include the new field. In most cases, it will not be necessary to also extend the nested serializer, which produces a minimal represenation of the model.
+
+### 6. Add field to forms
+
+Extend any forms to include the new field as appropriate. Common forms include:
+
+* **Credit/edit** - Manipulating a single object
+* **Bulk edit** - Performing a change on mnay objects at once
+* **CSV import** - The form used when bulk importing objects in CSV format
+* **Filter** - Displays the options available for filtering a list of objects (both UI and API)
+
+### 7. Extend object filter set
+
+If the new field should be filterable, add it to the `FilterSet` for the model. If the field should be searchable, remember to reference it in the FilterSet's `search()` method.
+
+### 8. Add column to object table
+
+If the new field will be included in the object list view, add a column to the model's table. For simple fields, adding the field name to `Meta.fields` will be sufficient. More complex fields may require explicitly declaring a new column.
+
+### 9. Update the UI templates
+
+Edit the object's view template to display the new field. There may also be a custom add/edit form template that needs to be updated.
+
+### 10. Adjust API and model tests
+
+Extend the model and/or API tests to verify that the new field and any accompanying validation logic perform as expected. This is especially important for relational fields.

docs/development/index.md

@@ -28,10 +28,3 @@ NetBox components are arranged into functional subsections called _apps_ (a carr
 * `tenancy`: Tenants (such as customers) to which NetBox objects may be assigned
 * `utilities`: Resources which are not user-facing (extendable classes, etc.)
 * `virtualization`: Virtual machines and clusters
-
-## Style Guide
-
-NetBox generally follows the [Django style guide](https://docs.djangoproject.com/en/dev/internals/contributing/writing-code/coding-style/), which is itself based on [PEP 8](https://www.python.org/dev/peps/pep-0008/). The following exceptions are noted:
-
-* [Pycodestyle](https://github.com/pycqa/pycodestyle) is used to validate code formatting, ignoring certain violations. See `scripts/cibuild.sh`.
-* Constants may be imported via wildcard (for example, `from .constants import *`).

docs/development/style-guide.md

@@ -0,0 +1,41 @@
+# Style Guide
+
+NetBox generally follows the [Django style guide](https://docs.djangoproject.com/en/dev/internals/contributing/writing-code/coding-style/), which is itself based on [PEP 8](https://www.python.org/dev/peps/pep-0008/). [Pycodestyle](https://github.com/pycqa/pycodestyle) is used to validate code formatting, ignoring certain violations. See `scripts/cibuild.sh`.
+
+## PEP 8 Exceptions
+
+* Wildcard imports (for example, `from .constants import *`) are acceptable under any of the following conditions:
+    * The library being import contains only constant declarations (`constants.py`)
+    * The library being imported explicitly defines `__all__` (e.g. `<app>.api.nested_serializers`)
+
+* Maximum line length is 120 characters (E501)
+    * This does not apply to HTML templates or to automatically generated code (e.g. database migrations).
+
+* Line breaks are permitted following binary operators (W504)
+
+## Enforcing Code Style
+
+The `pycodestyle` utility (previously `pep8`) is used by the CI process to enforce code style. It is strongly recommended to include as part of your commit process. A git commit hook is provided in the source at `scripts/git-hooks/pre-commit`. Linking to this script from `.git/hooks/` will invoke `pycodestyle` prior to every commit attempt and abort if the validation fails.
+
+```
+$ cd .git/hooks/
+$ ln -s ../../scripts/git-hooks/pre-commit
+```
+
+To invoke `pycodestyle` manually, run:
+
+```
+pycodestyle --ignore=W504,E501 netbox/
+```
+
+## General Guidance
+
+* When in doubt, remain consistent: It is better to be consistently incorrect than inconsistently correct. If you notice in the course of unrelated work a pattern that should be corrected, continue to follow the pattern for now and open a bug so that the entire code base can be evaluated at a later point.
+
+* No easter eggs. While they can be fun, NetBox must be considered as a business-critical tool. The potential, however minor, for introducing a bug caused by unnecessary logic is best avoided entirely.
+
+* Constants (variables which generally do not change) should be declared in `constants.py` within each app. Wildcard imports from the file are acceptable.
+
+* Every model should have a docstring. Every custom method should include an expalantion of its function.
+
+* Nested API serializers generate minimal representations of an object. These are stored separately from the primary serializers to avoid circular dependencies. Always import nested serializers from other apps directly. For example, from within the DCIM app you would write `from ipam.api.nested_serializers import NestedIPAddressSerializer`.