Adds a converter for a negative number in the URL

Author: Dimitar Tasev

WebApp/autoreduce_webapp/autoreduce_webapp/urls.py

@@ -8,7 +8,8 @@
 from django.conf import settings
 from django.conf.urls import include
 from django.contrib import admin
-from django.urls import path
+from django.urls import register_converter, path
+
 from instrument.views import runs
 from reduction_viewer import views as reduction_viewer_views
 
@@ -18,6 +19,19 @@
 handler404 = 'autoreduce_webapp.views.handler404'
 handler500 = 'autoreduce_webapp.views.handler500'
 
+
+class NegativeIntConverter:
+    regex = '-?\d+'
+
+    def to_python(self, value):
+        return int(value)
+
+    def to_url(self, value):
+        return '%d' % value
+
+
+register_converter(NegativeIntConverter, 'negint')
+
 urlpatterns = [
     # ===========================MISC================================= #
     path('', reduction_viewer_views.index, name='index'),
@@ -34,7 +48,7 @@
     path('instrument/', include('instrument.urls')),
 
     # ===========================EXPERIMENT========================== #
-    path('experiment/<int:reference_number>/', reduction_viewer_views.experiment_summary, name='experiment_summary'),
+    path('experiment/<negint:reference_number>/', reduction_viewer_views.experiment_summary, name='experiment_summary'),
 
     # ===========================SCRIPTS============================= #
     path('graph/', reduction_viewer_views.graph_home, name="graph"),