Use some read only fields in the Django admin

CHANGELOG.md

@@ -25,6 +25,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 
+- Made some fields read only in the Django admin to prevent slow page loads resulting in service interruptions. [#527](https://github.com/open-apparel-registry/open-apparel-registry/pull/527)
+
 ### Security
 
 

src/django/api/admin.py

@@ -1,5 +1,8 @@
+import json
+
 from django.contrib import admin
 from django.contrib.auth.admin import UserAdmin
+from django.utils.safestring import mark_safe
 from simple_history.admin import SimpleHistoryAdmin
 
 from api import models
@@ -15,12 +18,44 @@ class OarUserAdmin(UserAdmin):
 
 
 class FacilityHistoryAdmin(SimpleHistoryAdmin):
-    history_list_display = ['name', 'address', 'location']
+    history_list_display = ('name', 'address', 'location')
+
+    readonly_fields = ('created_from',)
+
+
+class FacilityListItemAdmin(admin.ModelAdmin):
+    exclude = ('processing_results',)
+    readonly_fields = ('facility_list', 'facility',
+                       'pretty_processing_results')
+
+    def pretty_processing_results(self, instance):
+        # The processing_results field is populated exclusively from processing
+        # code so we are not in danger of rendering potentially unsafe user
+        # submitted content
+        return mark_safe('<pre>{}</pre>'.format(
+            json.dumps(instance.processing_results, indent=2)))
+
+    pretty_processing_results.short_description = 'Processing results'
+
+
+class FacilityMatchAdmin(admin.ModelAdmin):
+    exclude = ('results',)
+    readonly_fields = ('facility_list_item', 'facility',
+                       'confidence', 'status', 'pretty_results')
+
+    def pretty_results(self, instance):
+        # The status field is populated exclusively from processing code so we
+        # are not in danger of rendering potentially unsafe user submitted
+        # content
+        return mark_safe('<pre>{}</pre>'.format(
+            json.dumps(instance.results, indent=2)))
+
+    pretty_results.short_description = 'Results'
 
 
 admin.site.register(models.User, OarUserAdmin)
 admin.site.register(models.Contributor)
 admin.site.register(models.FacilityList)
-admin.site.register(models.FacilityListItem)
+admin.site.register(models.FacilityListItem, FacilityListItemAdmin)
 admin.site.register(models.Facility, FacilityHistoryAdmin)
-admin.site.register(models.FacilityMatch)
+admin.site.register(models.FacilityMatch, FacilityMatchAdmin)