Remove old dependency on django_qr_code

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
@@ -407,8 +406,6 @@ CACHES = {
     }
 }
 
-QR_CODE_CACHE_ALIAS = 'qr-code'
-
 # Password validation
 # https://docs.djangoproject.com/en/1.10/ref/settings/#auth-password-validators
 

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
@@ -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/report/templatetags/barcode.py

@@ -0,0 +1,64 @@
+"""
+Template tags for rendering various barcodes
+"""
+
+import os
+import base64
+
+from io import BytesIO
+
+
+from django import template
+
+import qrcode
+import 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 qr_code(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 = 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)

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="{% qr_code qr_data %}">
     </div>
     {% else %}
-    <b>Error:</b><br>
-    {{ error_msg }}
+    <div class='alert alert-block alert-warning'>
+        {% trans "QR data not provided" %}
+    </div>
     {% endif %}
 </div>