Merge pull request #2957 from SchrodingersGat/locate-mixin

Adds plugin mixin to "locate" items

InvenTree/InvenTree/api_tester.py

@@ -142,6 +142,18 @@ class InvenTreeAPITestCase(APITestCase):
 
         return response
 
+    def put(self, url, data, expected_code=None, format='json'):
+        """
+        Issue a PUT request
+        """
+
+        response = self.client.put(url, data=data, format=format)
+
+        if expected_code is not None:
+            self.assertEqual(response.status_code, expected_code)
+
+        return response
+
     def options(self, url, expected_code=None):
         """
         Issue an OPTIONS request

InvenTree/InvenTree/api_version.py

@@ -4,11 +4,16 @@ InvenTree API version information
 
 
 # InvenTree API version
-INVENTREE_API_VERSION = 48
+INVENTREE_API_VERSION = 49
 
 """
 Increment this API version number whenever there is a significant change to the API that any clients need to know about
 
+v49 -> 2022-05-09 : https://github.com/inventree/InvenTree/pull/2957
+    - Allows filtering of plugin list by 'active' status
+    - Allows filtering of plugin list by 'mixin' support
+    - Adds endpoint to "identify" or "locate" stock items and locations (using plugins)
+
 v48 -> 2022-05-12 : https://github.com/inventree/InvenTree/pull/2977
     - Adds "export to file" functionality for PurchaseOrder API endpoint
     - Adds "export to file" functionality for SalesOrder API endpoint

InvenTree/order/api.py

@@ -27,6 +27,8 @@ import order.serializers as serializers
 from part.models import Part
 from users.models import Owner
 
+from plugin.serializers import MetadataSerializer
+
 
 class GeneralExtraLineList:
     """
@@ -347,6 +349,15 @@ class PurchaseOrderIssue(PurchaseOrderContextMixin, generics.CreateAPIView):
     serializer_class = serializers.PurchaseOrderIssueSerializer
 
 
+class PurchaseOrderMetadata(generics.RetrieveUpdateAPIView):
+    """API endpoint for viewing / updating PurchaseOrder metadata"""
+
+    def get_serializer(self, *args, **kwargs):
+        return MetadataSerializer(models.PurchaseOrder, *args, **kwargs)
+
+    queryset = models.PurchaseOrder.objects.all()
+
+
 class PurchaseOrderReceive(PurchaseOrderContextMixin, generics.CreateAPIView):
     """
     API endpoint to receive stock items against a purchase order.
@@ -916,6 +927,15 @@ class SalesOrderComplete(SalesOrderContextMixin, generics.CreateAPIView):
     serializer_class = serializers.SalesOrderCompleteSerializer
 
 
+class SalesOrderMetadata(generics.RetrieveUpdateAPIView):
+    """API endpoint for viewing / updating SalesOrder metadata"""
+
+    def get_serializer(self, *args, **kwargs):
+        return MetadataSerializer(models.SalesOrder, *args, **kwargs)
+
+    queryset = models.SalesOrder.objects.all()
+
+
 class SalesOrderAllocateSerials(SalesOrderContextMixin, generics.CreateAPIView):
     """
     API endpoint to allocation stock items against a SalesOrder,
@@ -1138,10 +1158,13 @@ order_api_urls = [
 
         # Individual purchase order detail URLs
         re_path(r'^(?P<pk>\d+)/', include([
-            re_path(r'^issue/', PurchaseOrderIssue.as_view(), name='api-po-issue'),
-            re_path(r'^receive/', PurchaseOrderReceive.as_view(), name='api-po-receive'),
             re_path(r'^cancel/', PurchaseOrderCancel.as_view(), name='api-po-cancel'),
             re_path(r'^complete/', PurchaseOrderComplete.as_view(), name='api-po-complete'),
+            re_path(r'^issue/', PurchaseOrderIssue.as_view(), name='api-po-issue'),
+            re_path(r'^metadata/', PurchaseOrderMetadata.as_view(), name='api-po-metadata'),
+            re_path(r'^receive/', PurchaseOrderReceive.as_view(), name='api-po-receive'),
+
+            # PurchaseOrder detail API endpoint
             re_path(r'.*$', PurchaseOrderDetail.as_view(), name='api-po-detail'),
         ])),
 
@@ -1178,10 +1201,13 @@ order_api_urls = [
 
         # Sales order detail view
         re_path(r'^(?P<pk>\d+)/', include([
-            re_path(r'^cancel/', SalesOrderCancel.as_view(), name='api-so-cancel'),
-            re_path(r'^complete/', SalesOrderComplete.as_view(), name='api-so-complete'),
             re_path(r'^allocate/', SalesOrderAllocate.as_view(), name='api-so-allocate'),
             re_path(r'^allocate-serials/', SalesOrderAllocateSerials.as_view(), name='api-so-allocate-serials'),
+            re_path(r'^cancel/', SalesOrderCancel.as_view(), name='api-so-cancel'),
+            re_path(r'^complete/', SalesOrderComplete.as_view(), name='api-so-complete'),
+            re_path(r'^metadata/', SalesOrderMetadata.as_view(), name='api-so-metadata'),
+
+            # SalesOrder detail endpoint
             re_path(r'^.*$', SalesOrderDetail.as_view(), name='api-so-detail'),
         ])),
 

InvenTree/order/migrations/0067_auto_20220516_1120.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.2.13 on 2022-05-16 11:20
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('order', '0066_alter_purchaseorder_supplier'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='purchaseorder',
+            name='metadata',
+            field=models.JSONField(blank=True, help_text='JSON metadata field, for use by external plugins', null=True, verbose_name='Plugin Metadata'),
+        ),
+        migrations.AddField(
+            model_name='salesorder',
+            name='metadata',
+            field=models.JSONField(blank=True, help_text='JSON metadata field, for use by external plugins', null=True, verbose_name='Plugin Metadata'),
+        ),
+    ]

InvenTree/order/models.py

@@ -30,7 +30,9 @@ from users import models as UserModels
 from part import models as PartModels
 from stock import models as stock_models
 from company.models import Company, SupplierPart
+
 from plugin.events import trigger_event
+from plugin.models import MetadataMixin
 
 import InvenTree.helpers
 from InvenTree.fields import InvenTreeModelMoneyField, RoundingDecimalField
@@ -97,7 +99,7 @@ def get_next_so_number():
     return reference
 
 
-class Order(ReferenceIndexingMixin):
+class Order(MetadataMixin, ReferenceIndexingMixin):
     """ Abstract model for an order.
 
     Instances of this class:

InvenTree/order/test_api.py

@@ -306,6 +306,22 @@ class PurchaseOrderTest(OrderTest):
 
         self.assertEqual(po.status, PurchaseOrderStatus.PLACED)
 
+    def test_po_metadata(self):
+        url = reverse('api-po-metadata', kwargs={'pk': 1})
+
+        self.patch(
+            url,
+            {
+                'metadata': {
+                    'yam': 'yum',
+                }
+            },
+            expected_code=200
+        )
+
+        order = models.PurchaseOrder.objects.get(pk=1)
+        self.assertEqual(order.get_metadata('yam'), 'yum')
+
 
 class PurchaseOrderReceiveTest(OrderTest):
     """
@@ -875,6 +891,22 @@ class SalesOrderTest(OrderTest):
 
         self.assertEqual(so.status, SalesOrderStatus.CANCELLED)
 
+    def test_so_metadata(self):
+        url = reverse('api-so-metadata', kwargs={'pk': 1})
+
+        self.patch(
+            url,
+            {
+                'metadata': {
+                    'xyz': 'abc',
+                }
+            },
+            expected_code=200
+        )
+
+        order = models.SalesOrder.objects.get(pk=1)
+        self.assertEqual(order.get_metadata('xyz'), 'abc')
+
 
 class SalesOrderAllocateTest(OrderTest):
     """

InvenTree/part/api.py

@@ -44,6 +44,7 @@ from stock.models import StockItem, StockLocation
 from common.models import InvenTreeSetting
 from build.models import Build, BuildItem
 import order.models
+from plugin.serializers import MetadataSerializer
 
 from . import serializers as part_serializers
 
@@ -203,6 +204,15 @@ class CategoryDetail(generics.RetrieveUpdateDestroyAPIView):
         return response
 
 
+class CategoryMetadata(generics.RetrieveUpdateAPIView):
+    """API endpoint for viewing / updating PartCategory metadata"""
+
+    def get_serializer(self, *args, **kwargs):
+        return MetadataSerializer(PartCategory, *args, **kwargs)
+
+    queryset = PartCategory.objects.all()
+
+
 class CategoryParameterList(generics.ListAPIView):
     """ API endpoint for accessing a list of PartCategoryParameterTemplate objects.
 
@@ -587,6 +597,17 @@ class PartScheduling(generics.RetrieveAPIView):
         return Response(schedule)
 
 
+class PartMetadata(generics.RetrieveUpdateAPIView):
+    """
+    API endpoint for viewing / updating Part metadata
+    """
+
+    def get_serializer(self, *args, **kwargs):
+        return MetadataSerializer(Part, *args, **kwargs)
+
+    queryset = Part.objects.all()
+
+
 class PartSerialNumberDetail(generics.RetrieveAPIView):
     """
     API endpoint for returning extra serial number information about a particular part
@@ -1912,7 +1933,15 @@ part_api_urls = [
         re_path(r'^tree/', CategoryTree.as_view(), name='api-part-category-tree'),
         re_path(r'^parameters/', CategoryParameterList.as_view(), name='api-part-category-parameter-list'),
 
-        re_path(r'^(?P<pk>\d+)/?', CategoryDetail.as_view(), name='api-part-category-detail'),
+        # Category detail endpoints
+        re_path(r'^(?P<pk>\d+)/', include([
+
+            re_path(r'^metadata/', CategoryMetadata.as_view(), name='api-part-category-metadata'),
+
+            # PartCategory detail endpoint
+            re_path(r'^.*$', CategoryDetail.as_view(), name='api-part-category-detail'),
+        ])),
+
         path('', CategoryList.as_view(), name='api-part-category-list'),
     ])),
 
@@ -1973,6 +2002,9 @@ part_api_urls = [
         # Endpoint for validating a BOM for the specific Part
         re_path(r'^bom-validate/', PartValidateBOM.as_view(), name='api-part-bom-validate'),
 
+        # Part metadata
+        re_path(r'^metadata/', PartMetadata.as_view(), name='api-part-metadata'),
+
         # Part detail endpoint
         re_path(r'^.*$', PartDetail.as_view(), name='api-part-detail'),
     ])),

InvenTree/part/migrations/0076_auto_20220516_0819.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.2.13 on 2022-05-16 08:19
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0075_auto_20211128_0151'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='part',
+            name='metadata',
+            field=models.JSONField(blank=True, help_text='JSON metadata field, for use by external plugins', null=True, verbose_name='Plugin Metadata'),
+        ),
+        migrations.AddField(
+            model_name='partcategory',
+            name='metadata',
+            field=models.JSONField(blank=True, help_text='JSON metadata field, for use by external plugins', null=True, verbose_name='Plugin Metadata'),
+        ),
+    ]

InvenTree/part/models.py

@@ -46,29 +46,29 @@ from common.models import InvenTreeSetting
 
 from InvenTree import helpers
 from InvenTree import validators
-from InvenTree.models import InvenTreeTree, InvenTreeAttachment, DataImportMixin
-from InvenTree.fields import InvenTreeURLField
-from InvenTree.helpers import decimal2string, normalize, decimal2money
 
 import InvenTree.ready
 import InvenTree.tasks
 
+from InvenTree.fields import InvenTreeURLField
+from InvenTree.helpers import decimal2string, normalize, decimal2money
+from InvenTree.models import InvenTreeTree, InvenTreeAttachment, DataImportMixin
 from InvenTree.status_codes import BuildStatus, PurchaseOrderStatus, SalesOrderStatus
 
+import common.models
 from build import models as BuildModels
 from order import models as OrderModels
 from company.models import SupplierPart
+import part.settings as part_settings
 from stock import models as StockModels
 
-import common.models
-
-import part.settings as part_settings
+from plugin.models import MetadataMixin
 
 
 logger = logging.getLogger("inventree")
 
 
-class PartCategory(InvenTreeTree):
+class PartCategory(MetadataMixin, InvenTreeTree):
     """ PartCategory provides hierarchical organization of Part objects.
 
     Attributes:
@@ -327,7 +327,7 @@ class PartManager(TreeManager):
 
 
 @cleanup.ignore
-class Part(MPTTModel):
+class Part(MetadataMixin, MPTTModel):
     """ The Part object represents an abstract part, the 'concept' of an actual entity.
 
     An actual physical instance of a Part is a StockItem which is treated separately.

InvenTree/part/test_api.py

@@ -21,6 +21,85 @@ import build.models
 import order.models
 
 
+class PartCategoryAPITest(InvenTreeAPITestCase):
+    """Unit tests for the PartCategory API"""
+
+    fixtures = [
+        'category',
+        'part',
+        'location',
+        'bom',
+        'company',
+        'test_templates',
+        'manufacturer_part',
+        'supplier_part',
+        'order',
+        'stock',
+    ]
+
+    roles = [
+        'part.change',
+        'part.add',
+        'part.delete',
+        'part_category.change',
+        'part_category.add',
+    ]
+
+    def test_category_list(self):
+
+        # List all part categories
+        url = reverse('api-part-category-list')
+
+        response = self.get(url, expected_code=200)
+
+        self.assertEqual(len(response.data), 8)
+
+        # Filter by parent, depth=1
+        response = self.get(
+            url,
+            {
+                'parent': 1,
+                'cascade': False,
+            },
+            expected_code=200
+        )
+
+        self.assertEqual(len(response.data), 3)
+
+        # Filter by parent, cascading
+        response = self.get(
+            url,
+            {
+                'parent': 1,
+                'cascade': True,
+            },
+            expected_code=200,
+        )
+
+        self.assertEqual(len(response.data), 5)
+
+    def test_category_metadata(self):
+        """Test metadata endpoint for the PartCategory"""
+
+        cat = PartCategory.objects.get(pk=1)
+
+        cat.metadata = {
+            'foo': 'bar',
+            'water': 'melon',
+            'abc': 'xyz',
+        }
+
+        cat.set_metadata('abc', 'ABC')
+
+        response = self.get(reverse('api-part-category-metadata', kwargs={'pk': 1}), expected_code=200)
+
+        metadata = response.data['metadata']
+
+        self.assertEqual(metadata['foo'], 'bar')
+        self.assertEqual(metadata['water'], 'melon')
+        self.assertEqual(metadata['abc'], 'ABC')
+
+
 class PartOptionsAPITest(InvenTreeAPITestCase):
     """
     Tests for the various OPTIONS endpoints in the /part/ API
@@ -1021,6 +1100,59 @@ class PartDetailTests(InvenTreeAPITestCase):
         self.assertEqual(data['in_stock'], 9000)
         self.assertEqual(data['unallocated_stock'], 9000)
 
+    def test_part_metadata(self):
+        """
+        Tests for the part metadata endpoint
+        """
+
+        url = reverse('api-part-metadata', kwargs={'pk': 1})
+
+        part = Part.objects.get(pk=1)
+
+        # Metadata is initially null
+        self.assertIsNone(part.metadata)
+
+        part.metadata = {'foo': 'bar'}
+        part.save()
+
+        response = self.get(url, expected_code=200)
+
+        self.assertEqual(response.data['metadata']['foo'], 'bar')
+
+        # Add more data via the API
+        # Using the 'patch' method causes the new data to be merged in
+        self.patch(
+            url,
+            {
+                'metadata': {
+                    'hello': 'world',
+                }
+            },
+            expected_code=200
+        )
+
+        part.refresh_from_db()
+
+        self.assertEqual(part.metadata['foo'], 'bar')
+        self.assertEqual(part.metadata['hello'], 'world')
+
+        # Now, issue a PUT request (existing data will be replacted)
+        self.put(
+            url,
+            {
+                'metadata': {
+                    'x': 'y'
+                },
+            },
+            expected_code=200
+        )
+
+        part.refresh_from_db()
+
+        self.assertFalse('foo' in part.metadata)
+        self.assertFalse('hello' in part.metadata)
+        self.assertEqual(part.metadata['x'], 'y')
+
 
 class PartAPIAggregationTest(InvenTreeAPITestCase):
     """

InvenTree/part/test_part.py

@@ -199,7 +199,7 @@ class PartTest(TestCase):
         with self.assertRaises(ValidationError):
             part_2.validate_unique()
 
-    def test_metadata(self):
+    def test_attributes(self):
         self.assertEqual(self.r1.name, 'R_2K2_0805')
         self.assertEqual(self.r1.get_absolute_url(), '/part/3/')
 
@@ -245,6 +245,24 @@ class PartTest(TestCase):
         self.assertEqual(float(self.r1.get_internal_price(1)), 0.08)
         self.assertEqual(float(self.r1.get_internal_price(10)), 0.5)
 
+    def test_metadata(self):
+        """Unit tests for the Part metadata field"""
+
+        p = Part.objects.get(pk=1)
+        self.assertIsNone(p.metadata)
+
+        self.assertIsNone(p.get_metadata('test'))
+        self.assertEqual(p.get_metadata('test', backup_value=123), 123)
+
+        # Test update via the set_metadata() method
+        p.set_metadata('test', 3)
+        self.assertEqual(p.get_metadata('test'), 3)
+
+        for k in ['apple', 'banana', 'carrot', 'carrot', 'banana']:
+            p.set_metadata(k, k)
+
+        self.assertEqual(len(p.metadata.keys()), 4)
+
 
 class TestTemplateTest(TestCase):
 

InvenTree/plugin/api.py

@@ -8,9 +8,7 @@ from __future__ import unicode_literals
 from django.conf import settings
 from django.urls import include, re_path
 
-from rest_framework import generics
-from rest_framework import status
-from rest_framework import permissions
+from rest_framework import filters, generics, permissions, status
 from rest_framework.exceptions import NotFound
 from rest_framework.response import Response
 
@@ -19,6 +17,7 @@ from django_filters.rest_framework import DjangoFilterBackend
 from common.api import GlobalSettingsPermissions
 from plugin.base.barcodes.api import barcode_api_urls
 from plugin.base.action.api import ActionPluginView
+from plugin.base.locate.api import LocatePluginView
 from plugin.models import PluginConfig, PluginSetting
 import plugin.serializers as PluginSerializers
 from plugin.registry import registry
@@ -38,6 +37,35 @@ class PluginList(generics.ListAPIView):
     serializer_class = PluginSerializers.PluginConfigSerializer
     queryset = PluginConfig.objects.all()
 
+    def filter_queryset(self, queryset):
+        queryset = super().filter_queryset(queryset)
+
+        params = self.request.query_params
+
+        # Filter plugins which support a given mixin
+        mixin = params.get('mixin', None)
+
+        if mixin:
+            matches = []
+
+            for result in queryset:
+                if mixin in result.mixins().keys():
+                    matches.append(result.pk)
+
+            queryset = queryset.filter(pk__in=matches)
+
+        return queryset
+
+    filter_backends = [
+        DjangoFilterBackend,
+        filters.SearchFilter,
+        filters.OrderingFilter,
+    ]
+
+    filter_fields = [
+        'active',
+    ]
+
     ordering_fields = [
         'key',
         'name',
@@ -163,6 +191,7 @@ class PluginSettingDetail(generics.RetrieveUpdateAPIView):
 plugin_api_urls = [
     re_path(r'^action/', ActionPluginView.as_view(), name='api-action-plugin'),
     re_path(r'^barcode/', include(barcode_api_urls)),
+    re_path(r'^locate/', LocatePluginView.as_view(), name='api-locate-plugin'),
 ]
 
 general_plugin_api_urls = [

InvenTree/plugin/base/locate/api.py

@@ -0,0 +1,82 @@
+"""API for location plugins"""
+
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from rest_framework import permissions
+from rest_framework.exceptions import ParseError, NotFound
+from rest_framework.response import Response
+from rest_framework.views import APIView
+
+from InvenTree.tasks import offload_task
+
+from plugin import registry
+from stock.models import StockItem, StockLocation
+
+
+class LocatePluginView(APIView):
+    """
+    Endpoint for using a custom plugin to identify or 'locate' a stock item or location
+    """
+
+    permission_classes = [
+        permissions.IsAuthenticated,
+    ]
+
+    def post(self, request, *args, **kwargs):
+
+        # Which plugin to we wish to use?
+        plugin = request.data.get('plugin', None)
+
+        if not plugin:
+            raise ParseError("'plugin' field must be supplied")
+
+        # Check that the plugin exists, and supports the 'locate' mixin
+        plugins = registry.with_mixin('locate')
+
+        if plugin not in [p.slug for p in plugins]:
+            raise ParseError(f"Plugin '{plugin}' is not installed, or does not support the location mixin")
+
+        # StockItem to identify
+        item_pk = request.data.get('item', None)
+
+        # StockLocation to identify
+        location_pk = request.data.get('location', None)
+
+        if not item_pk and not location_pk:
+            raise ParseError("Must supply either 'item' or 'location' parameter")
+
+        data = {
+            "success": "Identification plugin activated",
+            "plugin": plugin,
+        }
+
+        # StockItem takes priority
+        if item_pk:
+            try:
+                StockItem.objects.get(pk=item_pk)
+
+                offload_task('plugin.registry.call_function', plugin, 'locate_stock_item', item_pk)
+
+                data['item'] = item_pk
+
+                return Response(data)
+
+            except StockItem.DoesNotExist:
+                raise NotFound("StockItem matching PK '{item}' not found")
+
+        elif location_pk:
+            try:
+                StockLocation.objects.get(pk=location_pk)
+
+                offload_task('plugin.registry.call_function', plugin, 'locate_stock_location', location_pk)
+
+                data['location'] = location_pk
+
+                return Response(data)
+
+            except StockLocation.DoesNotExist:
+                raise NotFound("StockLocation matching PK {'location'} not found")
+
+        else:
+            raise NotFound()

InvenTree/plugin/base/locate/mixins.py

@@ -0,0 +1,74 @@
+"""Plugin mixin for locating stock items and locations"""
+
+import logging
+
+from plugin.helpers import MixinImplementationError
+
+logger = logging.getLogger('inventree')
+
+
+class LocateMixin:
+    """
+    Mixin class which provides support for 'locating' inventory items,
+    for example identifying the location of a particular StockLocation.
+
+    Plugins could implement audible or visual cues to direct attention to the location,
+    with (for e.g.) LED strips or buzzers, or some other method.
+
+    The plugins may also be used to *deliver* a particular stock item to the user.
+
+    A class which implements this mixin may implement the following methods:
+
+    - locate_stock_item : Used to locate / identify a particular stock item
+    - locate_stock_location : Used to locate / identify a particular stock location
+
+    Refer to the default method implementations below for more information!
+
+    """
+
+    class MixinMeta:
+        MIXIN_NAME = "Locate"
+
+    def __init__(self):
+        super().__init__()
+        self.add_mixin('locate', True, __class__)
+
+    def locate_stock_item(self, item_pk):
+        """
+        Attempt to locate a particular StockItem
+
+        Arguments:
+            item_pk: The PK (primary key) of the StockItem to be located
+
+        The default implementation for locating a StockItem
+        attempts to locate the StockLocation where the item is located.
+
+        An attempt is only made if the StockItem is *in stock*
+
+        Note: A custom implemenation could always change this behaviour
+        """
+
+        logger.info(f"LocateMixin: Attempting to locate StockItem pk={item_pk}")
+
+        from stock.models import StockItem
+
+        try:
+            item = StockItem.objects.get(pk=item_pk)
+
+            if item.in_stock and item.location is not None:
+                self.locate_stock_location(item.location.pk)
+
+        except StockItem.DoesNotExist:
+            logger.warning("LocateMixin: StockItem pk={item_pk} not found")
+            pass
+
+    def locate_stock_location(self, location_pk):
+        """
+        Attempt to location a particular StockLocation
+
+        Arguments:
+            location_pk: The PK (primary key) of the StockLocation to be located
+
+        Note: The default implementation here does nothing!
+        """
+        raise MixinImplementationError

InvenTree/plugin/mixins/__init__.py

@@ -10,6 +10,7 @@ from ..base.action.mixins import ActionMixin
 from ..base.barcodes.mixins import BarcodeMixin
 from ..base.event.mixins import EventMixin
 from ..base.label.mixins import LabelPrintingMixin
+from ..base.locate.mixins import LocateMixin
 
 __all__ = [
     'APICallMixin',
@@ -23,6 +24,7 @@ __all__ = [
     'PanelMixin',
     'ActionMixin',
     'BarcodeMixin',
+    'LocateMixin',
     'SingleNotificationMethod',
     'BulkNotificationMethod',
 ]

InvenTree/plugin/models.py

@@ -16,6 +16,65 @@ import common.models
 from plugin import InvenTreePlugin, registry
 
 
+class MetadataMixin(models.Model):
+    """
+    Model mixin class which adds a JSON metadata field to a model,
+    for use by any (and all) plugins.
+
+    The intent of this mixin is to provide a metadata field on a model instance,
+    for plugins to read / modify as required, to store any extra information.
+
+    The assumptions for models implementing this mixin are:
+
+    - The internal InvenTree business logic will make no use of this field
+    - Multiple plugins may read / write to this metadata field, and not assume they have sole rights
+    """
+
+    class Meta:
+        abstract = True
+
+    metadata = models.JSONField(
+        blank=True, null=True,
+        verbose_name=_('Plugin Metadata'),
+        help_text=_('JSON metadata field, for use by external plugins'),
+    )
+
+    def get_metadata(self, key: str, backup_value=None):
+        """
+        Finds metadata for this model instance, using the provided key for lookup
+
+        Args:
+            key: String key for requesting metadata. e.g. if a plugin is accessing the metadata, the plugin slug should be used
+
+        Returns:
+            Python dict object containing requested metadata. If no matching metadata is found, returns None
+        """
+
+        if self.metadata is None:
+            return backup_value
+
+        return self.metadata.get(key, backup_value)
+
+    def set_metadata(self, key: str, data, commit=True):
+        """
+        Save the provided metadata under the provided key.
+
+        Args:
+            key: String key for saving metadata
+            data: Data object to save - must be able to be rendered as a JSON string
+            overwrite: If true, existing metadata with the provided key will be overwritten. If false, a merge will be attempted
+        """
+
+        if self.metadata is None:
+            # Handle a null field value
+            self.metadata = {}
+
+        self.metadata[key] = data
+
+        if commit:
+            self.save()
+
+
 class PluginConfig(models.Model):
     """
     A PluginConfig object holds settings for plugins.

InvenTree/plugin/samples/locate/locate_sample.py

@@ -0,0 +1,38 @@
+"""
+Sample plugin for locating stock items / locations.
+
+Note: This plugin does not *actually* locate anything!
+"""
+
+import logging
+
+from plugin import InvenTreePlugin
+from plugin.mixins import LocateMixin
+
+
+logger = logging.getLogger('inventree')
+
+
+class SampleLocatePlugin(LocateMixin, InvenTreePlugin):
+    """
+    A very simple example of the 'locate' plugin.
+    This plugin class simply prints location information to the logger.
+    """
+
+    NAME = "SampleLocatePlugin"
+    SLUG = "samplelocate"
+    TITLE = "Sample plugin for locating items"
+
+    VERSION = "0.1"
+
+    def locate_stock_location(self, location_pk):
+
+        from stock.models import StockLocation
+
+        logger.info(f"SampleLocatePlugin attempting to locate location ID {location_pk}")
+
+        try:
+            location = StockLocation.objects.get(pk=location_pk)
+            logger.info(f"Location exists at '{location.pathstring}'")
+        except StockLocation.DoesNotExist:
+            logger.error(f"Location ID {location_pk} does not exist!")

InvenTree/plugin/serializers.py

@@ -19,6 +19,34 @@ from plugin.models import PluginConfig, PluginSetting, NotificationUserSetting
 from common.serializers import GenericReferencedSettingSerializer
 
 
+class MetadataSerializer(serializers.ModelSerializer):
+    """
+    Serializer class for model metadata API access.
+    """
+
+    metadata = serializers.JSONField(required=True)
+
+    def __init__(self, model_type, *args, **kwargs):
+
+        self.Meta.model = model_type
+        super().__init__(*args, **kwargs)
+
+    class Meta:
+        fields = [
+            'metadata',
+        ]
+
+    def update(self, instance, data):
+
+        if self.partial:
+            # Default behaviour is to "merge" new data in
+            metadata = instance.metadata.copy() if instance.metadata else {}
+            metadata.update(data['metadata'])
+            data['metadata'] = metadata
+
+        return super().update(instance, data)
+
+
 class PluginConfigSerializer(serializers.ModelSerializer):
     """
     Serializer for a PluginConfig:

InvenTree/plugin/templatetags/plugin_extras.py

@@ -45,6 +45,14 @@ def mixin_enabled(plugin, key, *args, **kwargs):
     return plugin.mixin_enabled(key)
 
 
+@register.simple_tag()
+def mixin_available(mixin, *args, **kwargs):
+    """
+    Returns True if there is at least one active plugin which supports the provided mixin
+    """
+    return len(registry.with_mixin(mixin)) > 0
+
+
 @register.simple_tag()
 def navigation_enabled(*args, **kwargs):
     """

InvenTree/stock/api.py

@@ -43,6 +43,8 @@ from order.serializers import PurchaseOrderSerializer
 from part.models import BomItem, Part, PartCategory
 from part.serializers import PartBriefSerializer
 
+from plugin.serializers import MetadataSerializer
+
 from stock.admin import StockItemResource
 from stock.models import StockLocation, StockItem
 from stock.models import StockItemTracking
@@ -92,6 +94,15 @@ class StockDetail(generics.RetrieveUpdateDestroyAPIView):
         return self.serializer_class(*args, **kwargs)
 
 
+class StockMetadata(generics.RetrieveUpdateAPIView):
+    """API endpoint for viewing / updating StockItem metadata"""
+
+    def get_serializer(self, *args, **kwargs):
+        return MetadataSerializer(StockItem, *args, **kwargs)
+
+    queryset = StockItem.objects.all()
+
+
 class StockItemContextMixin:
     """ Mixin class for adding StockItem object to serializer context """
 
@@ -1368,6 +1379,15 @@ class StockTrackingList(generics.ListAPIView):
     ]
 
 
+class LocationMetadata(generics.RetrieveUpdateAPIView):
+    """API endpoint for viewing / updating StockLocation metadata"""
+
+    def get_serializer(self, *args, **kwargs):
+        return MetadataSerializer(StockLocation, *args, **kwargs)
+
+    queryset = StockLocation.objects.all()
+
+
 class LocationDetail(generics.RetrieveUpdateDestroyAPIView):
     """ API endpoint for detail view of StockLocation object
 
@@ -1385,7 +1405,14 @@ stock_api_urls = [
 
         re_path(r'^tree/', StockLocationTree.as_view(), name='api-location-tree'),
 
-        re_path(r'^(?P<pk>\d+)/', LocationDetail.as_view(), name='api-location-detail'),
+        # Stock location detail endpoints
+        re_path(r'^(?P<pk>\d+)/', include([
+
+            re_path(r'^metadata/', LocationMetadata.as_view(), name='api-location-metadata'),
+
+            re_path(r'^.*$', LocationDetail.as_view(), name='api-location-detail'),
+        ])),
+
         re_path(r'^.*$', StockLocationList.as_view(), name='api-location-list'),
     ])),
 
@@ -1417,8 +1444,9 @@ stock_api_urls = [
 
     # Detail views for a single stock item
     re_path(r'^(?P<pk>\d+)/', include([
-        re_path(r'^serialize/', StockItemSerialize.as_view(), name='api-stock-item-serialize'),
         re_path(r'^install/', StockItemInstall.as_view(), name='api-stock-item-install'),
+        re_path(r'^metadata/', StockMetadata.as_view(), name='api-stock-item-metadata'),
+        re_path(r'^serialize/', StockItemSerialize.as_view(), name='api-stock-item-serialize'),
         re_path(r'^uninstall/', StockItemUninstall.as_view(), name='api-stock-item-uninstall'),
         re_path(r'^.*$', StockDetail.as_view(), name='api-stock-detail'),
     ])),

InvenTree/stock/migrations/0075_auto_20220515_1440.py

@@ -0,0 +1,27 @@
+# Generated by Django 3.2.13 on 2022-05-15 14:40
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0074_alter_stockitem_batch'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='stockitem',
+            name='metadata',
+            field=models.JSONField(blank=True, help_text='JSON metadata field, for use by external plugins', null=True, verbose_name='Plugin Metadata'),
+        ),
+        migrations.AddField(
+            model_name='stocklocation',
+            name='metadata',
+            field=models.JSONField(blank=True, help_text='JSON metadata field, for use by external plugins', null=True, verbose_name='Plugin Metadata'),
+        ),
+        migrations.AlterUniqueTogether(
+            name='stocklocation',
+            unique_together=set(),
+        ),
+    ]

InvenTree/stock/models.py

@@ -38,6 +38,7 @@ import common.models
 import report.models
 import label.models
 
+from plugin.models import MetadataMixin
 from plugin.events import trigger_event
 
 from InvenTree.status_codes import StockStatus, StockHistoryCode
@@ -51,7 +52,7 @@ from company import models as CompanyModels
 from part import models as PartModels
 
 
-class StockLocation(InvenTreeTree):
+class StockLocation(MetadataMixin, InvenTreeTree):
     """ Organization tree for StockItem objects
     A "StockLocation" can be considered a warehouse, or storage location
     Stock locations can be heirarchical as required
@@ -242,7 +243,7 @@ def generate_batch_code():
     return Template(batch_template).render(context)
 
 
-class StockItem(MPTTModel):
+class StockItem(MetadataMixin, MPTTModel):
     """
     A StockItem object represents a quantity of physical instances of a part.
 

InvenTree/stock/templates/stock/item_base.html

@@ -1,5 +1,6 @@
 {% extends "page_base.html" %}
 {% load static %}
+{% load plugin_extras %}
 {% load inventree_extras %}
 {% load status_codes %}
 {% load i18n %}
@@ -18,7 +19,6 @@
 <div id="breadcrumb-tree"></div>
 {% endblock breadcrumb_tree %}
 
-
 {% block heading %}
     {% trans "Stock Item" %}: {{ item.part.full_name}}
 {% endblock heading %}
@@ -29,6 +29,12 @@
 {% url 'admin:stock_stockitem_change' item.pk as url %}
 {% include "admin_button.html" with url=url %}
 {% endif %}
+{% mixin_available "locate" as locate_available %}
+{% if plugins_enabled and locate_available %}
+<button id='locate-item-button' title='{% trans "Locate stock item" %}' class='btn btn-outline-secondary' typy='button'>
+    <span class='fas fa-search-location'></span>
+</button>
+{% endif %}
 {% if barcodes %}
 <!-- Barcode actions menu -->
 <div class='btn-group' role='group'>
@@ -514,6 +520,14 @@ $("#barcode-scan-into-location").click(function() {
     });
 });
 
+{% if plugins_enabled %}
+$('#locate-item-button').click(function() {
+    locateItemOrLocation({
+        item: {{ item.pk }},
+    });
+});
+{% endif %}
+
 function itemAdjust(action) {
 
     inventreeGet(

InvenTree/stock/templates/stock/location.html

@@ -1,6 +1,7 @@
 {% extends "stock/stock_app_base.html" %}
 {% load static %}
 {% load inventree_extras %}
+{% load plugin_extras %}
 {% load i18n %}
 
 {% block sidebar %}
@@ -27,6 +28,14 @@
 {% include "admin_button.html" with url=url %}
 {% endif %}
 
+{% mixin_available "locate" as locate_available %}
+{% if location and plugins_enabled and locate_available %}
+<button id='locate-location-button' title='{% trans "Locate stock location" %}' class='btn btn-outline-secondary' typy='button'>
+    <span class='fas fa-search-location'></span>
+</button>
+
+{% endif %}
+
 {% if barcodes %}
 <!-- Barcode actions menu -->
 {% if location %}
@@ -206,6 +215,14 @@
 {% block js_ready %}
 {{ block.super }}
 
+    {% if plugins_enabled and location %}
+    $('#locate-location-button').click(function() {
+        locateItemOrLocation({
+            location: {{ location.pk }},
+        });
+    });
+    {% endif %}
+
     onPanelLoad('sublocations', function() {
         loadStockLocationTable($('#sublocation-table'), {
             params: {

InvenTree/templates/base.html

@@ -2,6 +2,7 @@
 {% load i18n %}
 {% load inventree_extras %}
 
+{% plugins_enabled as plugins_enabled %}
 {% settings_value 'BARCODE_ENABLE' as barcodes %}
 {% settings_value 'REPORT_ENABLE_TEST_REPORT' as test_report_enabled %}
 {% settings_value "REPORT_ENABLE" as report_enabled %}

InvenTree/templates/js/translated/label.js

@@ -236,17 +236,13 @@ function selectLabel(labels, items, options={}) {
     if (plugins_enabled) {
         inventreeGet(
             `/api/plugin/`,
-            {},
+            {
+                mixin: 'labels',
+            },
             {
                 async: false,
                 success: function(response) {
-                    response.forEach(function(plugin) {
-                        // Look for active plugins which implement the 'labels' mixin class
-                        if (plugin.active && plugin.mixins && plugin.mixins.labels) {
-                            // This plugin supports label printing
-                            plugins.push(plugin);
-                        }
-                    });
+                    plugins = response;
                 }
             }
         );

InvenTree/templates/js/translated/plugin.js

@@ -7,6 +7,7 @@
 
 /* exported
     installPlugin,
+    locateItemOrLocation
 */
 
 function installPlugin() {
@@ -24,3 +25,50 @@ function installPlugin() {
         }
     });
 }
+
+
+function locateItemOrLocation(options={}) {
+
+    if (!options.item && !options.location) {
+        console.error(`locateItemOrLocation: Either 'item' or 'location' must be provided!`);
+        return;
+    }
+
+    function performLocate(plugin) {
+        inventreePut(
+            '{% url "api-locate-plugin" %}',
+            {
+                plugin: plugin,
+                item: options.item,
+                location: options.location,
+            },
+            {
+                method: 'POST',
+            },
+        );
+    }
+
+    // Request the list of available 'locate' plugins
+    inventreeGet(
+        `/api/plugin/`,
+        {
+            mixin: 'locate',
+        },
+        {
+            success: function(plugins) {
+                // No 'locate' plugins are available!
+                if (plugins.length == 0) {
+                    console.warn(`No 'locate' plugins are available`);
+                } else if (plugins.length == 1) {
+                    // Only a single locate plugin is available
+                    performLocate(plugins[0].key);
+                } else {
+                    // More than 1 location plugin available
+                    // Select from a list
+                }
+            }
+        },
+    );
+}
+
+