Merge pull request #1342 from SchrodingersGat/label-improvements

Label improvements

InvenTree/InvenTree/settings.py

@@ -204,7 +204,6 @@ INSTALLED_APPS = [
     'crispy_forms',                         # Improved form rendering
     'import_export',                        # Import / export tables to file
     'django_cleanup.apps.CleanupConfig',    # Automatically delete orphaned MEDIA files
-    'qr_code',                              # Generate QR codes
     'mptt',                                 # Modified Preorder Tree Traversal
     'markdownx',                            # Markdown editing
     'markdownify',                          # Markdown template rendering
@@ -250,6 +249,7 @@ TEMPLATES = [
             os.path.join(BASE_DIR, 'templates'),
             # Allow templates in the reporting directory to be accessed
             os.path.join(MEDIA_ROOT, 'report'),
+            os.path.join(MEDIA_ROOT, 'label'),
         ],
         'APP_DIRS': True,
         'OPTIONS': {
@@ -407,8 +407,6 @@ CACHES = {
     }
 }
 
-QR_CODE_CACHE_ALIAS = 'qr-code'
-
 # Password validation
 # https://docs.djangoproject.com/en/1.10/ref/settings/#auth-password-validators
 

InvenTree/InvenTree/static/css/inventree.css

@@ -125,6 +125,7 @@
 .qr-container {
     width: 100%;
     align-content: center;
+    object-fit: fill;
 }
 
 .navbar-brand {

InvenTree/InvenTree/urls.py

@@ -9,7 +9,6 @@ from django.conf.urls import url, include
 from django.urls import path
 from django.contrib import admin
 from django.contrib.auth import views as auth_views
-from qr_code import urls as qr_code_urls
 
 from company.urls import company_urls
 from company.urls import supplier_part_urls
@@ -21,7 +20,7 @@ from stock.urls import stock_urls
 from build.urls import build_urls
 from order.urls import order_urls
 
-from barcode.api import barcode_api_urls
+from barcodes.api import barcode_api_urls
 from common.api import common_api_urls
 from part.api import part_api_urls, bom_api_urls
 from company.api import company_api_urls
@@ -141,8 +140,6 @@ urlpatterns = [
     url(r'^admin/shell/', include('django_admin_shell.urls')),
     url(r'^admin/', admin.site.urls, name='inventree-admin'),
 
-    url(r'^qr_code/', include(qr_code_urls, namespace='qr_code')),
-
     url(r'^index/', IndexView.as_view(), name='index'),
     url(r'^search/', SearchView.as_view(), name='search'),
     url(r'^stats/', DatabaseStatsView.as_view(), name='stats'),

InvenTree/barcodes/api.py

@@ -12,7 +12,7 @@ from rest_framework.views import APIView
 from stock.models import StockItem
 from stock.serializers import StockItemSerializer
 
-from barcode.barcode import load_barcode_plugins, hash_barcode
+from barcodes.barcode import load_barcode_plugins, hash_barcode
 
 
 class BarcodeScan(APIView):

InvenTree/barcodes/barcode.py

@@ -5,7 +5,7 @@ import hashlib
 import logging
 
 from InvenTree import plugins as InvenTreePlugins
-from barcode import plugins as BarcodePlugins
+from barcodes import plugins as BarcodePlugins
 
 from stock.models import StockItem
 from stock.serializers import StockItemSerializer, LocationSerializer

InvenTree/barcodes/plugins/digikey_barcode.py

@@ -4,7 +4,7 @@
 DigiKey barcode decoding
 """
 
-from barcode.barcode import BarcodePlugin
+from barcodes.barcode import BarcodePlugin
 
 
 class DigikeyBarcodePlugin(BarcodePlugin):

InvenTree/barcodes/plugins/inventree_barcode.py

@@ -13,7 +13,7 @@ references model objects actually exist in the database.
 
 import json
 
-from barcode.barcode import BarcodePlugin
+from barcodes.barcode import BarcodePlugin
 
 from stock.models import StockItem, StockLocation
 from part.models import Part

InvenTree/label/api.py

@@ -1,11 +1,10 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-import sys
-
 from django.utils.translation import ugettext as _
 from django.conf.urls import url, include
 from django.core.exceptions import ValidationError, FieldError
+from django.http import HttpResponse
 
 from django_filters.rest_framework import DjangoFilterBackend
 
@@ -13,6 +12,7 @@ from rest_framework import generics, filters
 from rest_framework.response import Response
 
 import InvenTree.helpers
+import common.models
 
 from stock.models import StockItem, StockLocation
 
@@ -40,6 +40,74 @@ class LabelListView(generics.ListAPIView):
     ]
 
 
+class LabelPrintMixin:
+    """
+    Mixin for printing labels
+    """
+
+    def print(self, request, items_to_print):
+        """
+        Print this label template against a number of pre-validated items
+        """
+
+        if len(items_to_print) == 0:
+            # No valid items provided, return an error message
+            data = {
+                'error': _('No valid objects provided to template'),
+            }
+
+            return Response(data, status=400)
+
+        outputs = []
+
+        # In debug mode, generate single HTML output, rather than PDF
+        debug_mode = common.models.InvenTreeSetting.get_setting('REPORT_DEBUG_MODE')
+
+        # Merge one or more PDF files into a single download
+        for item in items_to_print:
+            label = self.get_object()
+            label.object_to_print = item
+
+            if debug_mode:
+                outputs.append(label.render_as_string(request))
+            else:
+                outputs.append(label.render(request))
+
+        if debug_mode:
+            """
+            Contatenate all rendered templates into a single HTML string,
+            and return the string as a HTML response.
+            """
+
+            html = "\n".join(outputs)
+
+            return HttpResponse(html)
+        else:
+            """
+            Concatenate all rendered pages into a single PDF object,
+            and return the resulting document!
+            """
+
+            pages = []
+
+            if len(outputs) > 1:
+                # If more than one output is generated, merge them into a single file
+                for output in outputs:
+                    doc = output.get_document()
+                    for page in doc.pages:
+                        pages.append(page)
+
+                pdf = outputs[0].get_document().copy(pages).write_pdf()
+            else:
+                pdf = outputs[0].get_document().write_pdf()
+
+            return InvenTree.helpers.DownloadFile(
+                pdf,
+                'inventree_label.pdf',
+                content_type='application/pdf'
+            )
+
+
 class StockItemLabelMixin:
     """
     Mixin for extracting stock items from query params
@@ -158,7 +226,7 @@ class StockItemLabelDetail(generics.RetrieveUpdateDestroyAPIView):
     serializer_class = StockItemLabelSerializer
 
 
-class StockItemLabelPrint(generics.RetrieveAPIView, StockItemLabelMixin):
+class StockItemLabelPrint(generics.RetrieveAPIView, StockItemLabelMixin, LabelPrintMixin):
     """
     API endpoint for printing a StockItemLabel object
     """
@@ -173,34 +241,7 @@ class StockItemLabelPrint(generics.RetrieveAPIView, StockItemLabelMixin):
 
         items = self.get_items()
 
-        if len(items) == 0:
+        return self.print(request, items)
-            # No valid items provided, return an error message
-            data = {
-                'error': _('Must provide valid StockItem(s)'),
-            }
-
-            return Response(data, status=400)
-
-        label = self.get_object()
-
-        try:
-            pdf = label.render(items)
-        except:
-
-            e = sys.exc_info()[1]
-            
-            data = {
-                'error': _('Error during label rendering'),
-                'message': str(e),
-            }
-
-            return Response(data, status=400)
-
-        return InvenTree.helpers.DownloadFile(
-            pdf.getbuffer(),
-            'stock_item_label.pdf',
-            content_type='application/pdf'
-        )
 
 
 class StockLocationLabelMixin:
@@ -320,7 +361,7 @@ class StockLocationLabelDetail(generics.RetrieveUpdateDestroyAPIView):
     serializer_class = StockLocationLabelSerializer
 
 
-class StockLocationLabelPrint(generics.RetrieveAPIView, StockLocationLabelMixin):
+class StockLocationLabelPrint(generics.RetrieveAPIView, StockLocationLabelMixin, LabelPrintMixin):
     """
     API endpoint for printing a StockLocationLabel object
     """
@@ -332,35 +373,7 @@ class StockLocationLabelPrint(generics.RetrieveAPIView, StockLocationLabelMixin)
 
         locations = self.get_locations()
 
-        if len(locations) == 0:
+        return self.print(request, locations)
-            # No valid locations provided - return an error message
-
-            return Response(
-                {
-                    'error': _('Must provide valid StockLocation(s)'),
-                },
-                status=400,
-            )
-
-        label = self.get_object()
-
-        try:
-            pdf = label.render(locations)
-        except:
-            e = sys.exc_info()[1]
-
-            data = {
-                'error': _('Error during label rendering'),
-                'message': str(e),
-            }
-
-            return Response(data, status=400)
-
-        return InvenTree.helpers.DownloadFile(
-            pdf.getbuffer(),
-            'stock_location_label.pdf',
-            content_type='application/pdf'
-        )
 
 
 label_api_urls = [

InvenTree/label/apps.py

@@ -1,6 +1,7 @@
 import os
 import shutil
 import logging
+import hashlib
 
 from django.apps import AppConfig
 from django.conf import settings
@@ -9,6 +10,20 @@ from django.conf import settings
 logger = logging.getLogger(__name__)
 
 
+def hashFile(filename):
+    """
+    Calculate the MD5 hash of a file
+    """
+
+    md5 = hashlib.md5()
+
+    with open(filename, 'rb') as f:
+        data = f.read()
+        md5.update(data)
+
+    return md5.hexdigest()
+
+
 class LabelConfig(AppConfig):
     name = 'label'
 
@@ -35,6 +50,7 @@ class LabelConfig(AppConfig):
         src_dir = os.path.join(
             os.path.dirname(os.path.realpath(__file__)),
             'templates',
+            'label',
             'stockitem',
         )
 
@@ -54,6 +70,8 @@ class LabelConfig(AppConfig):
                 'file': 'qr.html',
                 'name': 'QR Code',
                 'description': 'Simple QR code label',
+                'width': 24,
+                'height': 24,
             },
         ]
 
@@ -70,7 +88,21 @@ class LabelConfig(AppConfig):
             src_file = os.path.join(src_dir, label['file'])
             dst_file = os.path.join(settings.MEDIA_ROOT, filename)
 
-            if not os.path.exists(dst_file):
+            to_copy = False
+
+            if os.path.exists(dst_file):
+                # File already exists - let's see if it is the "same",
+                # or if we need to overwrite it with a newer copy!
+
+                if not hashFile(dst_file) == hashFile(src_file):
+                    logger.info(f"Hash differs for '{filename}'")
+                    to_copy = True
+
+            else:
+                logger.info(f"Label template '{filename}' is not present")
+                to_copy = True
+
+            if to_copy:
                 logger.info(f"Copying label template '{dst_file}'")
                 shutil.copyfile(src_file, dst_file)
 
@@ -86,7 +118,9 @@ class LabelConfig(AppConfig):
                     description=label['description'],
                     label=filename,
                     filters='',
-                    enabled=True
+                    enabled=True,
+                    width=label['width'],
+                    height=label['height'],
                 )
             except:
                 pass
@@ -106,6 +140,7 @@ class LabelConfig(AppConfig):
         src_dir = os.path.join(
             os.path.dirname(os.path.realpath(__file__)),
             'templates',
+            'label',
             'stocklocation',
         )
 
@@ -125,11 +160,15 @@ class LabelConfig(AppConfig):
                 'file': 'qr.html',
                 'name': 'QR Code',
                 'description': 'Simple QR code label',
+                'width': 24,
+                'height': 24,
             },
             {
                 'file': 'qr_and_text.html',
                 'name': 'QR and text',
                 'description': 'Label with QR code and name of location',
+                'width': 50,
+                'height': 24,
             }
         ]
 
@@ -146,7 +185,21 @@ class LabelConfig(AppConfig):
             src_file = os.path.join(src_dir, label['file'])
             dst_file = os.path.join(settings.MEDIA_ROOT, filename)
 
-            if not os.path.exists(dst_file):
+            to_copy = False
+
+            if os.path.exists(dst_file):
+                # File already exists - let's see if it is the "same",
+                # or if we need to overwrite it with a newer copy!
+
+                if not hashFile(dst_file) == hashFile(src_file):
+                    logger.info(f"Hash differs for '{filename}'")
+                    to_copy = True
+
+            else:
+                logger.info(f"Label template '{filename}' is not present")
+                to_copy = True
+
+            if to_copy:
                 logger.info(f"Copying label template '{dst_file}'")
                 shutil.copyfile(src_file, dst_file)
 
@@ -162,7 +215,9 @@ class LabelConfig(AppConfig):
                     description=label['description'],
                     label=filename,
                     filters='',
-                    enabled=True
+                    enabled=True,
+                    width=label['width'],
+                    height=label['height'],
                 )
             except:
                 pass

InvenTree/label/migrations/0006_auto_20210222_1535.py

@@ -0,0 +1,34 @@
+# Generated by Django 3.0.7 on 2021-02-22 04:35
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('label', '0005_auto_20210113_2302'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='stockitemlabel',
+            name='height',
+            field=models.FloatField(default=20, help_text='Label height, specified in mm', validators=[django.core.validators.MinValueValidator(2)], verbose_name='Height [mm]'),
+        ),
+        migrations.AddField(
+            model_name='stockitemlabel',
+            name='width',
+            field=models.FloatField(default=50, help_text='Label width, specified in mm', validators=[django.core.validators.MinValueValidator(2)], verbose_name='Width [mm]'),
+        ),
+        migrations.AddField(
+            model_name='stocklocationlabel',
+            name='height',
+            field=models.FloatField(default=20, help_text='Label height, specified in mm', validators=[django.core.validators.MinValueValidator(2)], verbose_name='Height [mm]'),
+        ),
+        migrations.AddField(
+            model_name='stocklocationlabel',
+            name='width',
+            field=models.FloatField(default=50, help_text='Label width, specified in mm', validators=[django.core.validators.MinValueValidator(2)], verbose_name='Width [mm]'),
+        ),
+    ]

InvenTree/label/models.py

@@ -5,21 +5,35 @@ Label printing models
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
+import sys
 import os
-import io
+import logging
-
+import datetime
-from blabel import LabelWriter
 
+from django.conf import settings
 from django.db import models
-from django.core.validators import FileExtensionValidator
+from django.core.validators import FileExtensionValidator, MinValueValidator
 from django.core.exceptions import ValidationError, FieldError
 
+from django.template.loader import render_to_string
+
 from django.utils.translation import gettext_lazy as _
 
 from InvenTree.helpers import validateFilterString, normalize
 
+import common.models
 import stock.models
 
+try:
+    from django_weasyprint import WeasyTemplateResponseMixin
+except OSError as err:
+    print("OSError: {e}".format(e=err))
+    print("You may require some further system packages to be installed.")
+    sys.exit(1)
+
+
+logger = logging.getLogger(__name__)
+
 
 def rename_label(instance, filename):
     """ Place the label file into the correct subdirectory """
@@ -43,6 +57,21 @@ def validate_stock_location_filters(filters):
     return filters
 
 
+class WeasyprintLabelMixin(WeasyTemplateResponseMixin):
+    """
+    Class for rendering a label to a PDF
+    """
+
+    pdf_filename = 'label.pdf'
+    pdf_attachment = True
+
+    def __init__(self, request, template, **kwargs):
+
+        self.request = request
+        self.template_name = template
+        self.pdf_filename = kwargs.get('filename', 'label.pdf')
+
+
 class LabelTemplate(models.Model):
     """
     Base class for generic, filterable labels.
@@ -54,6 +83,9 @@ class LabelTemplate(models.Model):
     # Each class of label files will be stored in a separate subdirectory
     SUBDIR = "label"
     
+    # Object we will be printing against (will be filled out later)
+    object_to_print = None
+
     @property
     def template(self):
         return self.label.path
@@ -92,38 +124,90 @@ class LabelTemplate(models.Model):
         help_text=_('Label template is enabled'),
     )
 
-    def get_record_data(self, items):
+    width = models.FloatField(
+        default=50,
+        verbose_name=('Width [mm]'),
+        help_text=_('Label width, specified in mm'),
+        validators=[MinValueValidator(2)]
+    )
+
+    height = models.FloatField(
+        default=20,
+        verbose_name=_('Height [mm]'),
+        help_text=_('Label height, specified in mm'),
+        validators=[MinValueValidator(2)]
+    )
+
+    @property
+    def template_name(self):
         """
-        Return a list of dict objects, one for each item.
+        Returns the file system path to the template file.
+        Required for passing the file to an external process
         """
 
-        return []
+        template = self.label.name
+        template = template.replace('/', os.path.sep)
+        template = template.replace('\\', os.path.sep)
 
-    def render_to_file(self, filename, items, **kwargs):
+        template = os.path.join(settings.MEDIA_ROOT, template)
+
+        return template
+
+    def get_context_data(self, request):
         """
-        Render labels to a PDF file
+        Supply custom context data to the template for rendering.
+
+        Note: Override this in any subclass
         """
 
-        records = self.get_record_data(items)
+        return {}
 
-        writer = LabelWriter(self.template)
+    def context(self, request):
-
-        writer.write_labels(records, filename)
-
-    def render(self, items, **kwargs):
         """
-        Render labels to an in-memory PDF object, and return it
+        Provides context data to the template.
         """
 
-        records = self.get_record_data(items)
+        context = self.get_context_data(request)
 
-        writer = LabelWriter(self.template)
+        # Add "basic" context data which gets passed to every label
+        context['base_url'] = common.models.InvenTreeSetting.get_setting('INVENTREE_BASE_URL')
+        context['date'] = datetime.datetime.now().date()
+        context['datetime'] = datetime.datetime.now()
+        context['request'] = request
+        context['user'] = request.user
+        context['width'] = self.width
+        context['height'] = self.height
 
-        buffer = io.BytesIO()
+        return context
 
-        writer.write_labels(records, buffer)
+    def render_as_string(self, request, **kwargs):
+        """
+        Render the label to a HTML string
 
-        return buffer
+        Useful for debug mode (viewing generated code)
+        """
+
+        return render_to_string(self.template_name, self.context(request), request)
+
+    def render(self, request, **kwargs):
+        """
+        Render the label template to a PDF file
+
+        Uses django-weasyprint plugin to render HTML template
+        """
+
+        wp = WeasyprintLabelMixin(
+            request,
+            self.template_name,
+            base_url=request.build_absolute_uri("/"),
+            presentational_hints=True,
+            **kwargs
+        )
+
+        return wp.render_to_response(
+            self.context(request),
+            **kwargs
+        )
 
 
 class StockItemLabel(LabelTemplate):
@@ -157,29 +241,24 @@ class StockItemLabel(LabelTemplate):
 
         return items.exists()
 
-    def get_record_data(self, items):
+    def get_context_data(self, request):
         """
         Generate context data for each provided StockItem
         """
-        records = []
 
-        for item in items:
+        stock_item = self.object_to_print
 
-            # Add some basic information
+        return {
-            records.append({
+            'item': stock_item,
-                'item': item,
+            'part': stock_item.part,
-                'part': item.part,
+            'name': stock_item.part.full_name,
-                'name': item.part.name,
+            'ipn': stock_item.part.IPN,
-                'ipn': item.part.IPN,
+            'quantity': normalize(stock_item.quantity),
-                'quantity': normalize(item.quantity),
+            'serial': stock_item.serial,
-                'serial': item.serial,
+            'uid': stock_item.uid,
-                'uid': item.uid,
+            'qr_data': stock_item.format_barcode(brief=True),
-                'pk': item.pk,
+            'tests': stock_item.testResultMap()
-                'qr_data': item.format_barcode(brief=True),
+        }
-                'tests': item.testResultMap()
-            })
-
-        return records
 
 
 class StockLocationLabel(LabelTemplate):
@@ -212,17 +291,14 @@ class StockLocationLabel(LabelTemplate):
 
         return locs.exists()
 
-    def get_record_data(self, locations):
+    def get_context_data(self, request):
         """
         Generate context data for each provided StockLocation
         """
 
-        records = []
+        location = self.object_to_print
 
-        for loc in locations:
+        return {
-
+            'location': location,
-            records.append({
+            'qr_data': location.format_barcode(brief=True),
-                'location': loc,
+        }
-            })
-
-        return records

InvenTree/label/templates/label/label_base.html

@@ -0,0 +1,28 @@
+{% load report %}
+{% load barcode %}
+
+<head>
+    <style>
+        @page {
+            size: {{ width }}mm {{ height }}mm;
+            {% block margin %}
+            margin: 0mm;
+            {% endblock %}
+        }
+
+        img {
+            display: inline-block;
+            image-rendering: pixelated;
+        }
+
+        {% block style %}
+        {% endblock %}
+
+    </style>
+</head>
+
+<body>
+    {% block content %}
+    <!-- Label data rendered here! -->
+    {% endblock %}
+</body>

InvenTree/label/templates/label/stockitem/qr.html

@@ -0,0 +1,20 @@
+{% extends "label/label_base.html" %}
+
+{% load barcode %}
+
+{% block style %}
+
+.qr {
+    position: fixed;
+    left: 0mm;
+    top: 0mm;
+    height: {{ height }}mm;
+    width: {{ height }}mm;
+}
+
+{% endblock %}
+
+{% block content %}
+
+<img class='qr' src='{% qrcode qr_data %}'>
+{% endblock %}

InvenTree/label/templates/label/stocklocation/qr.html

@@ -0,0 +1,20 @@
+{% extends "label/label_base.html" %}
+
+{% load barcode %}
+
+{% block style %}
+
+.qr {
+    position: fixed;
+    left: 0mm;
+    top: 0mm;
+    height: {{ height }}mm;
+    width: {{ height }}mm;
+}
+
+{% endblock %}
+
+{% block content %}
+
+<img class='qr' src='{% qrcode qr_data %}'>
+{% endblock %}

InvenTree/label/templates/label/stocklocation/qr_and_text.html

@@ -0,0 +1,33 @@
+{% extends "label/label_base.html" %}
+
+{% load barcode %}
+
+{% block style %}
+
+.qr {
+    position: fixed;
+    left: 0mm;
+    top: 0mm;
+    height: {{ height }}mm;
+    width: {{ height }}mm;
+}
+
+.loc {
+    font-family: Arial, Helvetica, sans-serif;
+    display: inline;
+    position: absolute;
+    left: {{ height }}mm;
+    top: 2mm;
+}
+
+{% endblock %}
+
+{% block content %}
+
+<img class='qr' src='{% qrcode qr_data %}'>
+
+<div class='loc'>
+    {{ location.name }}
+</div>
+
+{% endblock %}

InvenTree/label/templates/stockitem/qr.html

@@ -1,16 +0,0 @@
-<style>
-@page {
-    width: 24mm;
-    height: 24mm;
-    padding: 1mm;
-}
-
-.qr {
-    margin: 2px;
-    width: 22mm;
-    height: 22mm;
-}
-
-</style>
-
-<img class='qr' src="{{ label_tools.qr_code(item.barcode) }}"/>

InvenTree/label/templates/stocklocation/qr.html

@@ -1,16 +0,0 @@
-<style>
-@page {
-    width: 24mm;
-    height: 24mm;
-    padding: 1mm;
-}
-
-.qr {
-    margin: 2px;
-    width: 22mm;
-    height: 22mm;
-}
-
-</style>
-
-<img class='qr' src="{{ label_tools.qr_code(location.barcode) }}"/>

InvenTree/label/templates/stocklocation/qr_and_text.html

@@ -1,43 +0,0 @@
-<style>
-    @page {
-        width: 75mm;
-        height: 24mm;
-        padding: 1mm;
-    }
-    
-    .location {
-        padding: 5px;
-        font-weight: bold;
-        font-family: Arial, Helvetica, sans-serif;
-        height: 100%;
-        vertical-align: middle;
-        float: right;
-        display: inline;
-        font-size: 125%;
-        position: absolute;
-        top: 0mm;
-        left: 23mm;
-        white-space: nowrap;
-        overflow: hidden;
-        text-overflow: ellipsis;
-    }
-    
-    .qr {
-        margin: 2px;
-        width: 22mm;
-        height: 22mm;
-    }
-    
-    </style>
-    
-    <img class='qr' src="{{ label_tools.qr_code(location.barcode) }}"/>
-    
-    <div class='location'>
-        {{ location.name }}
-        <br>
-        <br>
-        <hr>
-        Location ID: {{ location.pk }}
-        </div>
-    </div>
-    

InvenTree/part/test_views.py

@@ -270,14 +270,12 @@ class PartQRTest(PartViewTestCase):
         data = str(response.content)
 
         self.assertIn('Part QR Code', data)
-        self.assertIn('<img class=', data)
+        self.assertIn('<img src=', data)
 
     def test_invalid_part(self):
         response = self.client.get(reverse('part-qr', args=(9999,)), HTTP_X_REQUESTED_WITH='XMLHttpRequest')
 
-        data = str(response.content)
+        self.assertEqual(response.status_code, 200)
-        
-        self.assertIn('Error:', data)
 
 
 class CategoryTest(PartViewTestCase):

InvenTree/report/api.py

@@ -164,7 +164,7 @@ class ReportPrintMixin:
             report.object_to_print = item
 
             if debug_mode:
-                outputs.append(report.render_to_string(request))
+                outputs.append(report.render_as_string(request))
             else:
                 outputs.append(report.render(request))
 

InvenTree/report/models.py

@@ -221,7 +221,7 @@ class ReportTemplateBase(ReportBase):
 
         return context
 
-    def render_to_string(self, request, **kwargs):
+    def render_as_string(self, request, **kwargs):
         """
         Render the report to a HTML stiring.
 

InvenTree/report/templatetags/barcode.py

@@ -0,0 +1,81 @@
+"""
+Template tags for rendering various barcodes
+"""
+
+import base64
+from io import BytesIO
+
+from django import template
+
+import qrcode as python_qrcode
+import barcode as python_barcode
+
+register = template.Library()
+
+
+def image_data(img, fmt='PNG'):
+    """
+    Convert an image into HTML renderable data
+
+    Returns a string ``data:image/FMT;base64,xxxxxxxxx`` which can be rendered to an <img> tag
+    """
+
+    buffered = BytesIO()
+    img.save(buffered, format=fmt)
+    
+    img_str = base64.b64encode(buffered.getvalue())
+
+    return f"data:image/{fmt.lower()};charset=utf-8;base64," + img_str.decode()
+
+
+@register.simple_tag()
+def qrcode(data, **kwargs):
+    """
+    Return a byte-encoded QR code image
+
+    Optional kwargs
+    ---------------
+
+    fill_color: Fill color (default = black)
+    back_color: Background color (default = white)
+    """
+
+    # Construct "default" values
+    params = dict(
+        box_size=20,
+        border=1,
+    )
+
+    fill_color = kwargs.pop('fill_color', 'black')
+    back_color = kwargs.pop('back_color', 'white')
+
+    params.update(**kwargs)
+
+    qr = python_qrcode.QRCode(**params)
+
+    qr.add_data(data, optimize=20)
+    qr.make(fit=True)
+
+    qri = qr.make_image(fill_color=fill_color, back_color=back_color)
+
+    return image_data(qri)
+
+
+@register.simple_tag()
+def barcode(data, barcode_class='code128', **kwargs):
+    """
+    Render a barcode
+    """
+
+    constructor = python_barcode.get_barcode_class(barcode_class)
+
+    data = str(data).zfill(constructor.digits)
+
+    writer = python_barcode.writer.ImageWriter
+
+    barcode_image = constructor(data, writer=writer())
+
+    image = barcode_image.render(writer_options=kwargs)
+
+    # Render to byte-encoded PNG
+    return image_data(image)

InvenTree/stock/test_views.py

@@ -105,9 +105,6 @@ class StockItemTest(StockViewTestCase):
         response = self.client.get(reverse('stock-item-qr', args=(9999,)), HTTP_X_REQUESTED_WITH='XMLHttpRequest')
         self.assertEqual(response.status_code, 200)
 
-        data = str(response.content)
-        self.assertIn('Error:', data)
-
     def test_adjust_items(self):
         url = reverse('stock-adjust')
 

InvenTree/templates/js/label.js

@@ -114,6 +114,18 @@ function selectLabel(labels, items, options={}) {
      * (via AJAX) from the server.
      */
 
+    // If only a single label template is provided,
+    // just run with that!
+
+    if (labels.length == 1) {
+        if (options.success) {
+            options.success(labels[0].pk);
+        }
+
+        return;
+    }
+
+
     var modal = options.modal || '#modal-form';
 
     var label_list = makeOptionsList(

InvenTree/templates/qr_code.html

@@ -1,12 +1,14 @@
-{% load qr_code %}
+{% load barcode %}
+{% load i18n %}
 
 <div class='container' style='width: 80%;'>
     {% if qr_data %}
     <div class='qr-container'>
-        <img class='qr-code' src="{% qr_url_from_text qr_data size='m' image_format='png' error_correction='m' %}" alt="QR Code">
+        <img src="{% qrcode qr_data %}">
     </div>
     {% else %}
-    <b>Error:</b><br>
+    <div class='alert alert-block alert-warning'>
-    {{ error_msg }}
+        {% trans "QR data not provided" %}
+    </div>
     {% endif %}
 </div>

requirements.txt

@@ -1,7 +1,6 @@
 wheel>=0.34.2                   # Wheel
 Django==3.0.7                   # Django package
 pillow==7.1.0                   # Image manipulation
-blabel==0.1.3                   # Simple PDF label printing
 djangorestframework==3.10.3     # DRF framework
 django-dbbackup==3.3.0          # Database backup / restore functionality
 django-cors-headers==3.2.0      # CORS headers extension for DRF
@@ -16,7 +15,6 @@ tablib==0.13.0                  # Import / export data files
 django-crispy-forms==1.8.1      # Form helpers
 django-import-export==2.0.0     # Data import / export for admin interface
 django-cleanup==5.1.0           # Manage deletion of old / unused uploaded files
-django-qr-code==1.2.0           # Generate QR codes
 flake8==3.8.3                   # PEP checking
 pep8-naming==0.11.1             # PEP naming convention extension
 coverage==5.3                   # Unit test coverage
@@ -31,5 +29,7 @@ certifi                         # Certifi is (most likely) installed through one
 django-error-report==0.2.0      # Error report viewer for the admin interface
 django-test-migrations==1.1.0   # Unit testing for database migrations 
 django-migration-linter==2.5.0  # Linting checks for database migrations
+python-barcode[images]==0.13.1  # Barcode generator
+qrcode[pil]==6.1                # QR code generator
 
 inventree                       # Install the latest version of the InvenTree API python library