move plugins into directories

docs/extend/plugins/action.md

@@ -0,0 +1,18 @@
+---
+title: Action Plugins
+---
+
+### Action Plugins
+
+Arbitrary "actions" can be called by POSTing data to the `/api/action/` endpoint. The POST request must include the name of the action to be performed, and a matching ActionPlugin plugin must be loaded by the server. Arbitrary data can also be provided to the action plugin via the POST data:
+
+```
+POST {
+    action: "MyCustomAction",
+    data: {
+        foo: "bar",
+    }
+}
+```
+
+For an example of a very simple action plugin, refer to `/InvenTree/plugin/builtin/action/simpleactionplugin.py`

docs/extend/plugins/barcode.md

@@ -0,0 +1,25 @@
+---
+title: Barcode Plugins
+---
+
+### Barcode Plugins
+
+InvenTree supports decoding of arbitrary barcode data via a **Barcode Plugin** interface. Barcode data POSTed to the `/api/barcode/` endpoint will be supplied to all loaded barcode plugins, and the first plugin to successfully interpret the barcode data will return a response to the client.
+
+InvenTree can generate native QR codes to represent database objects (e.g. a single StockItem). This barcode can then be used to perform quick lookup of a stock item or location in the database. A client application (for example the InvenTree mobile app) scans a barcode, and sends the barcode data to the InvenTree server. The server then uses the **InvenTreeBarcodePlugin** (found at `/InvenTree/plugins/barcode/inventree.py`) to decode the supplied barcode data.
+
+Any third-party barcodes can be decoded by writing a matching plugin to decode the barcode data. These plugins could then perform a server-side action or render a JSON response back to the client for further action.
+
+Some examples of possible uses for barcode integration:
+
+- Stock lookup by scanning a barcode on a box of items
+- Receiving goods against a PurchaseOrder by scanning a supplier barcode
+- Perform a stock adjustment action (e.g. take 10 parts from stock whenever a barcode is scanned)
+
+Barcode data are POSTed to the server as follows:
+
+```
+POST {
+    barcode_data: "[(>someBarcodeDataWhichThePluginKnowsHowToDealWith"
+}
+```

docs/extend/plugins/integration.md

@@ -0,0 +1,115 @@
+---
+title: Integration Plugins
+---
+
+### Integration Plugins
+
+Integration Plugins provide a wide area of deep integration into the interface of InvenTree.
+
+For an example of a pretty much full Integration Plugin, refer to `/InvenTree/plugin/samples/integration/sample.py`
+
+#### Plugin Options
+
+Some metadata options can be defined as constants in the plugins class.
+
+``` python
+PLUGIN_SLUG = None  # Used in URLs, setting-names etc. when a unique slug as a reference is needed -> the plugin name is used if not set
+PLUGIN_TITLE = None  # A nice human friendly name for the plugin -> used in titles, as plugin name etc.
+
+AUTHOR = None  # Author of the plugin, git commit information is used if not present
+PUBLISH_DATE = None  # Publishing date of the plugin, git commit information is used if not present
+VERSION = None  # Version of the plugin
+WEBSITE = None  # Website for the plugin, developer etc. -> is shown in plugin overview if set
+```
+
+
+
+#### Installing a Plugin
+
+Plugins can either be loaded from paths in the InvenTree install directory or as a plugin installed via pip. We recommend installation via pip as this enables hassle-free upgrades.
+
+For development new plugins can be placed ina a subdirectroy in `src/InvenTree/plugins`. Built-In plugins ship in `src/InvenTree/plugin/builtin`. To achive full unit-testing for all mixins there are some sample implementations in `src/InvenTree/plugin/samples`. These are not loaded in production mode.
+
+#### Mixins
+
+Common use cases are covered by pre-supplied modules in the form of mixins (similar to how [django](https://docs.djangoproject.com/en/3.2/topics/class-based-views/mixins/) does it). Each mixin enables the integration into a specific area of InvenTree. Sometimes it also enhances the plugin with helper functions to supply often used functions out-of-the-box.
+
+##### Basic Mixin Functions
+
+All mixins are registered with the plugin on start-up so you can access all added mixins as a dict with the `plugin.registered_mixins` property that is added to each plugin.
+
+The function `plugin.mixin_enabled(key)` returns if a mixin is present in a plugin and configured correctly.
+
+##### Initialisation
+
+Each mixin must call `super().__init__()` in it's `__init__` function and register itself with a call to `self.add_mixin()`. Check out the built-in mixins for examples.
+
+``` python
+def __init__(self):
+    super().__init__()
+    self.add_mixin('settings', 'has_settings', __class__)
+```
+
+##### Meta Options
+
+Each mixin can define additional options as a Meta subclass. These are used to describe the mixin.
+
+
+#### SettingsMixin
+
+Use the class constant `SETTINGS` for a dict of settings that should be added as global database settings.  
+The dict must be formatted similar to the following sample. Take a look at the settings defined in `InvenTree.common.models.InvenTreeSetting` for all possible parameters.
+
+
+``` python
+SETTINGS = {
+    'PO_FUNCTION_ENABLE': {
+        'name': _('Enable PO'),
+        'description': _('Enable PO functionality in InvenTree interface'),
+        'default': True,
+        'validator': bool,
+    },
+}
+```
+
+!!! note "Use carefully"
+    All global and user settings are exposed to the frontend code and can be read out via the browsers developer tools. You can protect a setting from export by adding `'protected': True` to sensitive settings.
+    You can access settings in frontend JS code under the global variable `global_settings`.
+
+This mixin defines the helper functions `plugin.get_setting` and `plugin.set_seting` to access all plugin specific settings.
+
+
+#### UrlsMixin
+
+Use the class constant `URLS` for a array of URLs that should be added to InvenTrees URL paths or override the `plugin.setup_urls` function.  
+The array has to contain valid URL patterns as defined in the [django documentation](https://docs.djangoproject.com/en/3.2/topics/http/urls/).
+
+``` python
+URLS = [
+    url(r'increase/(?P<location>\d+)/(?P<pk>\d+)/', self.view_increase, name='increase-level'),
+]
+```
+
+The URLs get exposed under `/plugin/{plugin.slug}/*` and get exposed to the template engine with the prefix `plugin:{plugin.slug}:` (for usage with the [url tag](https://docs.djangoproject.com/en/3.2/ref/templates/builtins/#url)).
+
+
+#### NavigationMixin
+
+Use the class constant `NAVIGATION` for a array of links that should be added to InvenTrees navigation header.  
+The array must contain at least one dict that at least define a name and a link for each element. The link must be formatted for a URL pattern name lookup - links to external sites are not possible directly. The optional icon must be a class reference to an icon (InvenTree ships with fontawesome 4 by default).
+
+``` python
+NAVIGATION = [
+    {'name': 'SampleIntegration', 'link': 'plugin:sample:hi', 'icon': 'fas fa-box'},
+]
+```
+
+The optional class constants `NAVIGATION_TAB_NAME` and `NAVIGATION_TAB_ICON` can be used to change the name and icon for the parent navigation node.
+
+
+#### AppMixin
+
+If this mixin is added to a plugin the directory the plugin class is defined in is added to InvenTrees `INSTALLED_APPS`.
+
+!!! warning "Danger Zone"
+    Only use this plugin if you have an understanding of djangos [app system](https://docs.djangoproject.com/en/3.2/ref/applications). Plugins with this mixin are deeply integrated into InvenTree and can cause difficult to reproduce or long-running errors. Use the built-in testing functions of django to make sure your code does not cause unwanted behaviour in InvenTree.

docs/extend/plugins/report.md

@@ -0,0 +1,10 @@
+---
+title: Reporting Plugins
+---
+
+### Reporting Plugins
+
+InvenTree can generate customized reports (for example stocktake information, packing lists, acceptance test reports, etc).
+
+!!! missing "TODO"
+	Include more information here on reporting plugins

mkdocs.yml

@@ -110,7 +110,12 @@ nav:
   - Extend:
     - API: extend/api.md
     - Python Interface: extend/python.md
-    - Plugins: extend/plugins.md
+    - Plugins:
+      - Overview: extend/plugins.md
+      - Reporting: extend/plugins/report.md
+      - Barcode: extend/plugins/barcode.md
+      - Action: extend/plugins/action.md
+      - Integration: extend/plugins/integration.md
     - Themes: extend/themes.md
     - Third-Party: extend/integrate.md
   - App: