Refactor barcode endoint

- Moved code into 'barcode' directory

InvenTree/barcode/barcode.py

@@ -0,0 +1,126 @@
+# -*- coding: utf-8 -*-
+
+import hashlib
+import json
+
+from InvenTree import plugins as InvenTreePlugins
+from barcode import plugins as BarcodePlugins
+
+from stock.serializers import StockItemSerializer, LocationSerializer
+from part.serializers import PartSerializer
+
+
+def hash_barcode(barcode_data):
+    """
+    Calculate an MD5 hash of barcode data
+    """
+
+    hash = hashlib.md5(str(barcode_data).encode())
+    return str(hash.hexdigest())
+
+
+class BarcodePlugin:
+    """
+    Base class for barcode handling.
+    Custom barcode plugins should extend this class as necessary.
+    """
+
+    # Override the barcode plugin name for each sub-class
+    PLUGIN_NAME = ""
+
+    @property
+    def name(self):
+        return self.PLUGIN_NAME
+
+    def __init__(self, barcode_data):
+
+        self.data = barcode_data
+
+    def getStockItem(self):
+        """
+        Attempt to retrieve a StockItem associated with this barcode.
+        Default implementation returns None
+        """
+
+        return None
+
+    def renderStockItem(self, item):
+        """
+        Render a stock item to JSON response
+        """
+
+        serializer = StockItemSerializer(item, part_detail=True, location_detail=True, supplier_part_detail=True)
+        return serializer.data
+
+
+    def getStockLocation(self):
+        """
+        Attempt to retrieve a StockLocation associated with this barcode.
+        Default implementation returns None
+        """
+
+        return None
+
+    def renderStockLocation(self, loc):
+        """
+        Render a stock location to a JSON response
+        """
+
+        serializer = LocationSerializer(loc)
+        return serializer.data
+
+    def getPart(self):
+        """
+        Attempt to retrieve a Part associated with this barcode.
+        Default implementation returns None
+        """
+
+        return None 
+
+    def renderPart(self, part):
+        """
+        Render a part to JSON response
+        """
+
+        serializer = PartSerializer(part)
+        return serializer.data
+
+    def hash(self):
+        """
+        Calculate a hash for the barcode data.
+        This is supposed to uniquely identify the barcode contents,
+        at least within the bardcode sub-type.
+
+        The default implementation simply returns an MD5 hash of the barcode data,
+        encoded to a string.
+
+        This may be sufficient for most applications, but can obviously be overridden
+        by a subclass.
+
+        """
+
+        return hash_barcode(self.data)
+
+    def validate(self):
+        """
+        Default implementation returns False
+        """
+        return False
+
+
+def load_barcode_plugins():
+    """
+    Function to load all barcode plugins
+    """
+
+    print("Loading barcode plugins")
+
+    plugins = InvenTreePlugins.get_plugins(BarcodePlugins, BarcodePlugin)
+
+    if len(plugins) > 0:
+        print("Discovered {n} plugins:".format(n=len(plugins)))
+
+        for p in plugins:
+            print(" - {p}".format(p=p.PLUGIN_NAME))
+
+    return plugins