added logging for evidence tag changes

action/urls.py

@@ -8,4 +8,5 @@ urlpatterns = [
     path("new/", views.ChangeStateView.as_view(), name="change_state"),
     path('note/add/', views.AddNoteView.as_view(), name='add_note'),
     path('note/edit/<int:pk>', views.UpdateNoteView.as_view(), name='update_note'),
+    path('note/delete/<int:pk>', views.DeleteNoteView.as_view(), name='delete_note'),
 ]

action/views.py

@@ -9,70 +9,73 @@ from action.models import State, StateDefinition, Note, DeviceLog
 from device.models import Device
 
 
-class ChangeStateView(View):
+class ChangeStateView(FormView):
+    form_class = ChangeStateForm
 
-    def post(self, request, *args, **kwargs):
-        form = ChangeStateForm(request.POST)
-        
-        if form.is_valid():
-            previous_state = form.cleaned_data['previous_state']
-            new_state = form.cleaned_data['new_state']
-            snapshot_uuid = form.cleaned_data['snapshot_uuid']
+    def form_valid(self, form):
+        previous_state = form.cleaned_data['previous_state']
+        new_state = form.cleaned_data['new_state']
+        snapshot_uuid = form.cleaned_data['snapshot_uuid']
 
-            State.objects.create(
-                snapshot_uuid=snapshot_uuid,
-                state=new_state,
-                user=self.request.user,
-                institution=self.request.user.institution,
-            )
+        State.objects.create(
+            snapshot_uuid=snapshot_uuid,
+            state=new_state,
+            user=self.request.user,
+            institution=self.request.user.institution,
+        )
 
-            message = _("<Created> State '{}'. Previous State: '{}' ".format(new_state, previous_state) )
-            DeviceLog.objects.create(
-                snapshot_uuid=snapshot_uuid,
-                event=message,
-                user=self.request.user,
-                institution=self.request.user.institution,
-            )
+        message = _("<Created> State '{}'. Previous State: '{}'").format(new_state, previous_state)
+        DeviceLog.objects.create(
+            snapshot_uuid=snapshot_uuid,
+            event=message,
+            user=self.request.user,
+            institution=self.request.user.institution,
+        )
+        messages.success(self.request, _("State successfully changed from '{}' to '{}'").format(previous_state, new_state))
+        return super().form_valid(form)
 
-            messages.success(request, _("State succesfuly changed from '{}' to '{}' ".format(previous_state, new_state) ) )
-        else:
-            messages.error(request, "There was an error with your submission.")
+    def form_invalid(self, form):
+        messages.error(self.request, _("There was an error with your submission."))
+        return redirect(self.get_success_url())
 
-        return redirect(request.META.get('HTTP_REFERER') )
+    def get_success_url(self):
+        return self.request.META.get('HTTP_REFERER') or reverse_lazy('device:details')
 
 
-class AddNoteView(View):
+class AddNoteView(FormView):
+    form_class = AddNoteForm
 
-    def post(self, request, *args, **kwargs):
-        form = AddNoteForm(request.POST)
+    def form_valid(self, form):
+        note_text = form.cleaned_data['note']
+        snapshot_uuid = form.cleaned_data['snapshot_uuid']
+        Note.objects.create(
+            snapshot_uuid=snapshot_uuid,
+            description=note_text,
+            user=self.request.user,
+            institution=self.request.user.institution,
+        )
 
-        if form.is_valid():
-            note = form.cleaned_data['note']
-            snapshot_uuid = form.cleaned_data['snapshot_uuid']
-            Note.objects.create(
-                snapshot_uuid=snapshot_uuid,
-                description=note,
-                user=self.request.user,
-                institution=self.request.user.institution,
-            )
+        message = _("<Created> Note: '{}'").format(note_text)
+        DeviceLog.objects.create(
+            snapshot_uuid=snapshot_uuid,
+            event=message,
+            user=self.request.user,
+            institution=self.request.user.institution,
+        )
+        messages.success(self.request, _("Note has been added"))
+        return super().form_valid(form)
 
-            message = _("<Created> Note: '{}' ".format(note) )
-            DeviceLog.objects.create(
-                snapshot_uuid=snapshot_uuid,
-                event=message,
-                user=self.request.user,
-                institution=self.request.user.institution,
-            )
-            messages.success(request, _("Note has been added"))
-        else:
-            messages.error(request, "There was an error with your submission.")
+    def form_invalid(self, form):
+        messages.error(self.request, _("There was an error with your submission."))
+        return redirect(self.get_success_url())
+
+    def get_success_url(self):
+        return self.request.META.get('HTTP_REFERER') or reverse_lazy('device:details')
 
-        return redirect(request.META.get('HTTP_REFERER') )
 
 class UpdateNoteView(UpdateView):
     model = Note
     fields = ['description']
-    template_name = 'device/templates/details.html'
     pk_url_kwarg = 'pk'
 
     def form_valid(self, form):
@@ -88,9 +91,50 @@ class UpdateNoteView(UpdateView):
                 user=self.request.user,
                 institution=self.request.user.institution,
             )
-
-        messages.success(self.request, "Note has been updated.")
+            messages.success(self.request, "Note has been updated.")
         return super().form_valid(form)
-
+    
+    def form_invalid(self, form):
+        new_description = form.cleaned_data.get('description', '').strip()
+        if not new_description:
+            messages.error(self.request, _("Note cannot be empty."))
+        super().form_invalid(form)
+        return redirect(self.get_success_url())
+    
     def get_success_url(self):
         return self.request.META.get('HTTP_REFERER', reverse_lazy('device:details'))
+
+
+class DeleteNoteView(View):
+    model = Note
+
+    def post(self, request, *args, **kwargs):
+        self.pk = kwargs['pk']
+        referer = request.META.get('HTTP_REFERER')
+        if not referer:
+            raise Http404("No referer header found")
+
+        self.object = get_object_or_404(
+            self.model,
+            pk=self.pk,
+            institution=self.request.user.institution
+        )
+        description = self.object.description
+        snapshot_uuid= self.object.snapshot_uuid
+
+        if request.user != self.object.user and not request.user.is_admin:
+            messages.error(request, _("You do not have permission to delete this note."))
+            return redirect(referer)
+
+        message = _("<Deleted> Note. Description: '{}'. ").format(description)
+        DeviceLog.objects.create(
+            snapshot_uuid=snapshot_uuid,
+            event=message,
+            user=request.user,
+            institution=request.user.institution,
+        )
+        messages.warning(self.request, _("Note '{}' deleted successfully.").format(description))
+
+        self.object.delete()
+
+        return redirect(referer)

admin/templates/states_panel.html

@@ -21,8 +21,10 @@
     </caption>
   <thead class="table-light">
     <tr>
-      <th scope="col" width="5%" class="text-start">
+      <th scope="col" width="1%" class="text-start">
       </th>
+      <th scope="col" width="5%" class="text-center">
+      #</th>
       <th scope="col">{% trans "State Definition" %}
       </th>
       <th scope="col" width="15%" class="text-center">{% trans "Actions" %}
@@ -37,9 +39,11 @@
         class="align-items-center">
 
         <td class="">
-          <i class="fas fa-duotone fa-solid fa-grip px-1" aria-hidden="true">
-          </i>
-          <strong> {{ state_definition.order }} </strong>
+          <i class="bi bi-grip-vertical" aria-hidden="true">
+            </i>
+        </td>
+        <td class="text-center">
+          <strong>{{ state_definition.order }} </strong>
         </td>
         <td class="font-monospace">
           {{ state_definition.state }}
@@ -48,16 +52,21 @@
         <!-- action buttons -->
         <td>
           <div class="btn-group float-end">
-            <button type="button" class="btn btn-sm btn-info text-white" data-bs-toggle="modal" data-bs-target="#editStateModal{{ state_definition.id }}">
-              <i class="bi bi-pencil">
-              </i> {% trans 'Edit' %}
+            <button 
+              type="button" 
+              class="btn btn-sm btn-outline-info d-flex align-items-center" 
+              data-bs-toggle="modal"  data-bs-target="#editStateModal{{ state_definition.id }}">
+              <i class="bi bi-pencil me-1"></i>
+              {% trans 'Edit' %}
             </button>
-            <button type="button" class="btn btn-sm btn-danger" data-bs-toggle="modal" data-bs-target="#deleteStateModal{{ state_definition.id }}">
-              <i class="bi bi-trash">
-              </i>
+            <button 
+              type="button" class="btn btn-sm btn-outline-danger d-flex align-items-center" 
+              data-bs-toggle="modal" 
+              data-bs-target="#deleteStateModal{{ state_definition.id }}" >
+              <i class="bi bi-trash me-1"></i>
+              {% trans 'Delete' %}
             </button>
           </div>
-
         </td>
       </tr>
     {% endfor %}

device/templates/details.html

@@ -4,7 +4,7 @@
 {% block content %}
 
 <div class="position-fixed" style="bottom: 2rem; right: 2rem; z-index: 9999; display: flex; gap: 0.5rem;">
-  <button class="btn btn-outline-warning d-flex align-items-center shadow" type="button"
+  <button class="btn btn-warning d-flex align-items-center shadow" type="button"
           data-bs-toggle="offcanvas" data-bs-target="#notesOffcanvas" aria-controls="notesOffcanvas"
           data-bs-toggle="tooltip" data-bs-placement="left" title="{% trans 'View recent notes' %}">
     <i class="bi bi-journal-text me-1"></i>
@@ -19,24 +19,28 @@
     <h5 id="notesOffcanvasLabel">{% trans "Latest Notes" %}</h5>
     <button type="button" class="btn-close" data-bs-dismiss="offcanvas" aria-label="Close"></button>
   </div>        
-  <div class="offcanvas-body">
+  <div class="offcanvas-body" style="margin-bottom: 5rem;">
     {% for note in device_notes|slice:":4" %}
       <div class="card mb-3 shadow-sm">
-        <div class="card-body">
+        <div class="card-body"> 
           <div>
             <small class="text-muted">
               {{ note.date|timesince }} {% trans "ago" %}
             </small>
-          </div>
+
           {% if user == note.user or user.is_admin %}
+          <span class="badge bg-warning text-dark ms-2">{% trans "Editable" %}</span>
+          </div>
           <blockquote
               class="blockquote mt-2 p-2 bg-light fst-italic"
               contenteditable="true"
-              style="font-size: 1em!important"
+              style="font-size: 1.2em!important"
               data-note-id="{{ note.id }}"
+              title="{% trans 'Click to edit this note' %}"
               oninput="toggleSaveLink(this)">
           {% else %}
-            <blockquote style="font-size: 1em!important" class="blockquote mt-2 p-2 fst-italic">
+          </div>
+            <blockquote style="font-size: 1.2em!important" class="blockquote mt-2 p-2 fst-italic">
           {% endif %}
           <p data-note-id="{{ note.id }}">
             {{ note.description }}
@@ -49,6 +53,7 @@
           {% if user == note.user or user.is_admin %}
             <div class="d-flex justify-content-end align-items-center">
 
+              <!-- update note button -->
               <form
                 id="updateNoteForm{{ note.id }}"
                 method="post"
@@ -60,22 +65,35 @@
                 <a
                   type="submit"
                   id="saveLink{{ note.id }}"
-                  class="text-muted disabled me-4"
+                  class="text-muted disabled me-4  border border-light rounded"
                   style="pointer-events: none;"
                   title="{% trans 'Save changes' %}"
                   onclick="submitUpdatedNote('{{ note.id }}'); return false;"
                 >
-                  <i class="fas fa-save"></i>
-                </a>
-              </form>
-
-              <form class="d-inline" method="post" action="">
-                {% csrf_token %}
-                <a type="submit" class="text-danger" onclick="return confirm('{% trans 'Are you sure you want to delete this note?' %}')" title="{% trans 'Delete note' %}">
-                  <i class="bi bi-trash"></i>
+                  <i class="fas fa-save px-1"></i>
                 </a>
               </form>
+              
+              <!-- delete note button -->
+              <button type="button" class="btn btn-link btn-outline-danger btn-sm text-danger" id="deleteIcon{{ note.id }}" title="{% trans 'Delete note' %}" data-bs-toggle="collapse" data-bs-target="#confirmDelete{{ note.id }}">
+                <i class="bi bi-trash"></i>
+              </button>
             </div>
+            <form class="d-inline" method="post" action="{% url 'action:delete_note' note.id %}">
+              {% csrf_token %}
+              <div class="collapse mt-2" id="confirmDelete{{ note.id }}">
+                <div class="card card-body border border-danger text-center">
+                  <p class="mb-2">{% trans 'Are you sure you want to delete this note?' %}</p>
+                  <a
+                    href="#"
+                    class="btn btn-sm btn-outline-danger"
+                    onclick="submitDeleteForm({{ note.id }}); return false;"
+                  >
+                    {% trans 'Confirm delete' %}
+                  </a>
+                </div>
+              </div>
+            </form>
           {% endif %}
           
         </div>
@@ -101,7 +119,9 @@
           {% trans "Change state" %}
           {% if device_states %}
             ({{ device_states.0.state }})
-          {% endif %}
+          {% else %}
+            ( {% trans "None" %} )
+            {% endif %}
         </a>
         <ul class="dropdown-menu" aria-labelledby="addStateDropdown" style="width: 100%;">
           {% for state in state_definitions %}
@@ -188,6 +208,7 @@
 
   {% include 'tabs/evidences.html' %}
 
+  <!-- Add a note popup -->
   <div class="modal fade" id="addNoteModal" tabindex="-1" aria-labelledby="addNoteModalLabel" aria-hidden="true">
     <div class="modal-dialog">
       <div class="modal-content">
@@ -238,8 +259,8 @@
     function toggleSaveLink(blockquoteElem) {
       const saveLink = document.getElementById("saveLink" + blockquoteElem.dataset.noteId);
 
-      saveLink.classList.remove("disabled", "text-muted");
-      saveLink.classList.add("text-success");
+      saveLink.classList.remove("disabled", "text-muted", "border-light");
+      saveLink.classList.add("text-success", "border-success");
       saveLink.style.pointerEvents = "auto"; 
       
     }
@@ -251,5 +272,9 @@
       descriptionField.value = newText;
       document.getElementById('updateNoteForm' + noteId).submit();
     }
+    //simpler are u sure? confirmation message
+    function submitDeleteForm(noteId) {
+      document.getElementById('confirmDelete' + noteId).closest('form').submit();
+    }
   </script>
 {% endblock %}

device/templates/tabs/user_properties.html

@@ -2,30 +2,23 @@
 {% load i18n %}
 
 <div class="tab-pane fade" id="user_properties">
-      <div class="btn-group mt-1 mb-3">
-        <a href="{% url 'device:add_user_property' object.pk %}" class="btn btn-primary">
-            <i class="bi bi-plus">
-            </i>
-          {% trans 'New user property' %}
-        </a>
-      </div>
+    <div class="d-flex justify-content-end mt-1 mb-3">
+      <a href="{% url 'device:add_user_property' object.pk %}"
+        class="btn btn-green-admin d-flex align-items-center">
+        <i class="bi bi-plus me-1"></i>
+        {% trans 'New user property' %}
+      </a>
+    </div>
 
-      <h5 class="card-title">{% trans 'User properties' %}
-      </h5>
-      <table class="table table-striped">
-        <thead>
+      <h5 class="card-title">{% trans 'User properties' %}</h5>
+
+      <table class="table table-hover table-bordered table-responsive align-middle">
+        <thead class="table-light">
           <tr>
-            <th scope="col">
-              {% trans 'Key' %}
-            </th>
-            <th scope="col">
-              {% trans 'Value' %}
-            </th>
-            <th scope="col" data-type="date" data-format="YYYY-MM-DD HH:mm">
-              {% trans 'Created on' %}
-            </th>
-            <th>
-            </th>
+            <th scope="col">{% trans 'Key' %}</th>
+            <th scope="col">{% trans 'Value' %}</th>
+            <th scope="col" data-type="date" class="text-end" data-format="YYYY-MM-DD HH:mm">{% trans 'Created on' %}</th>
+            <th scope="col" width="5%" class="text-end" title="{% trans 'Actions' %}"></th>
           </tr>
         </thead>
         <tbody>
@@ -35,17 +28,23 @@
                 </td>
                 <td>{{ a.value }}
                 </td>
-                <td>{{ a.created }}
+                <td class="text-end">{{ a.created }}
                 </td>
               <td>
-                <div class="btn-group float-end">
-                  <button type="button" class="btn btn-sm btn-primary" data-bs-toggle="modal" data-bs-target="#editModal{{ a.id }}">
-                      <i class="bi bi-pencil">
-                      </i> {% trans 'Edit' %}
+                <div class="btn-group ">
+                  <button
+                    type="button"
+                    class="btn btn-sm btn-outline-info d-flex align-items-center" data-bs-toggle="modal"
+                    data-bs-target="#editModal{{ a.id }}" >
+                    <i class="bi bi-pencil me-1"></i>
+                    {% trans 'Edit' %}
                   </button>
-                  <button type="button" class="btn btn-sm btn-danger" data-bs-toggle="modal" data-bs-target="#deleteModal{{ a.id }}">
-                      <i class="bi bi-trash">
-                      </i>
+                  <button
+                    type="button"
+                    class="btn btn-sm btn-outline-danger d-flex align-items-center"
+                    data-bs-toggle="modal" data-bs-target="#deleteModal{{ a.id }}">
+                    <i class="bi bi-trash me-1"></i>
+                    {% trans 'Delete' %}
                   </button>
                 </div>
               </td>

device/views.py

@@ -190,7 +190,6 @@ class AddUserPropertyView(DashboardView, CreateView):
     template_name = "new_user_property.html"
     title = _("New User Property")
     breadcrumb = "Device / New Property"
-    success_url = reverse_lazy('dashboard:unassigned_devices')
     model = UserProperty
     fields = ("key", "value")
 
@@ -215,17 +214,13 @@ class AddUserPropertyView(DashboardView, CreateView):
     def get_form_kwargs(self):
         pk = self.kwargs.get('pk')
         institution = self.request.user.institution
-        self.property = SystemProperty.objects.filter(
-            owner=institution,
-            value=pk,
-        ).first()
+        self.property = get_object_or_404(SystemProperty, owner=institution, value=pk)
 
-        if not self.property:
-            raise Http404
+        return super().get_form_kwargs()
+
+    def get_success_url(self):
+        return reverse_lazy('device:details', args=[self.kwargs.get('pk')])
 
-        self.success_url = reverse_lazy('device:details', args=[pk])
-        kwargs = super().get_form_kwargs()
-        return kwargs
 
 class UpdateUserPropertyView(DashboardView, UpdateView):
     template_name = "new_user_property.html"
@@ -234,37 +229,34 @@ class UpdateUserPropertyView(DashboardView, UpdateView):
     model = UserProperty
     fields = ("key", "value")
 
-    def get_form_kwargs(self):
+    def get_queryset(self):
         pk = self.kwargs.get('pk')
-        user_property = get_object_or_404(UserProperty, pk=pk, owner=self.request.user.institution)
-
-        if not user_property:
-            raise Http404
-
-        kwargs = super().get_form_kwargs()
-        kwargs['instance'] = user_property
-        return kwargs
+        institution = self.request.user.institution
+        return UserProperty.objects.filter(pk=pk, owner=institution)
 
     def form_valid(self, form):
-        old_key= self.object.key
-        old_value = self.object.value
-        new_key = form.cleaned_data['key']
-        new_value = form.cleaned_data['value']
+
+        old_instance = self.get_object()
+        old_key = old_instance.key
+        old_value = old_instance.value
 
         form.instance.owner = self.request.user.institution
         form.instance.user = self.request.user
         form.instance.type = UserProperty.Type.USER
-        response = super().form_valid(form)
-        messages.success(self.request, _("User property updated successfully."))
 
-        message = _("<Updated> UserProperty: {}: {} to {}: {}".format(old_key, old_value, new_key, new_value ))
+        new_key = form.cleaned_data['key']
+        new_value = form.cleaned_data['value']
+
+        message = _("<Updated> UserProperty: {}: {} to {}: {}".format(old_key, old_value, new_key, new_value))
         DeviceLog.objects.create(
             snapshot_uuid=form.instance.uuid,
             event=message,
             user=self.request.user,
             institution=self.request.user.institution
         )
-        return response
+
+        messages.success(self.request, _("User property updated successfully."))
+        return super().form_valid(form)
 
     def get_success_url(self):
         return self.request.META.get('HTTP_REFERER', reverse_lazy('device:details', args=[self.object.pk]))
@@ -273,17 +265,14 @@ class UpdateUserPropertyView(DashboardView, UpdateView):
 class DeleteUserPropertyView(DashboardView, DeleteView):
     model = UserProperty
 
-    def post(self, request, *args, **kwargs):
-        self.pk = kwargs['pk']
-        referer = request.META.get('HTTP_REFERER')
-        if not referer:
-            raise Http404("No referer header found")
+    def get_queryset(self):
+        return UserProperty.objects.filter(owner=self.request.user.institution)
+
+    #using post() method because delete() method from DeleteView has some issues with messages framework
+    def post(self, request, *args, **kwargs):
+        self.object = self.get_object()
+        self.object.delete()
 
-        self.object = get_object_or_404(
-            self.model,
-            pk=self.pk,
-            owner=self.request.user.institution
-        )
         message = _("<Deleted> User Property: {}:{}".format(self.object.key, self.object.value ))
         DeviceLog.objects.create(
             snapshot_uuid=self.object.uuid,
@@ -292,12 +281,15 @@ class DeleteUserPropertyView(DashboardView, DeleteView):
             institution=self.request.user.institution
         )
 
-        self.object.delete()
         messages.info(self.request, _("User property deleted successfully."))
 
-        # Redirect back to the original URL
-        return redirect(referer)
+        return self.handle_success()
 
+    def handle_success(self):
+        return redirect(self.get_success_url())
+
+    def get_success_url(self):
+        return self.request.META.get('HTTP_REFERER', reverse_lazy('device:details', args=[self.object.pk]))
 
 class AddDocumentView(DashboardView, CreateView):
     template_name = "new_user_property.html"

evidence/forms.py

@@ -10,6 +10,7 @@ from device.models import Device
 from evidence.parse import Build
 from evidence.models import SystemProperty, UserProperty
 from utils.save_snapshots import move_json, save_in_disk
+from action.models import DeviceLog
 
 
 class UploadForm(forms.Form):
@@ -98,19 +99,31 @@ class UserTagForm(forms.Form):
             return
 
         if self.instance:
+            old_value = self.instance.value
             if not self.tag:
+                message =_("<Deleted> Evidence Tag. Old Value: '{}'").format(old_value)
                 self.instance.delete()
-            self.instance.value = self.tag
-            self.instance.save()
-            return
-
-        SystemProperty.objects.create(
-            uuid=self.uuid,
-            key='CUSTOM_ID',
-            value=self.tag,
-            owner=self.user.institution,
-            user=self.user
-        )
+            else:
+                self.instance.value = self.tag
+                self.instance.save()
+                if old_value != self.tag:
+                    message=_("<Updated> Evidence Tag. Old Value: '{}'. New Value: '{}'").format(old_value, self.tag)
+        else:
+            message =_("<Created> Evidence Tag. Value: '{}'").format(self.tag)
+            SystemProperty.objects.create(
+                uuid=self.uuid,
+                key='CUSTOM_ID',
+                value=self.tag,
+                owner=self.user.institution,
+                user=self.user
+            )
+        
+        DeviceLog.objects.create(
+                snapshot_uuid=self.uuid,
+                event= message,
+                user=self.user,
+                institution=self.user.institution
+            )
 
 
 class ImportForm(forms.Form):

evidence/templates/ev_details.html

@@ -94,7 +94,7 @@
 	    </div>
 	    {% if form.tag.value %}
 	    <div class="col-1">
-	      <a class="btn btn-yellow" href="{% url 'device:delete_user_property' form.pk %}">{% translate "Delete" %}</a>
+	      <a class="btn btn-yellow" href="{% url 'evidence:delete_tag' form.pk %}">{% translate "Delete" %}</a>
 	    </div>
 	    {% endif %}
 	  </div>

evidence/urls.py

@@ -20,4 +20,5 @@ urlpatterns = [
     path("<uuid:pk>", views.EvidenceView.as_view(), name="details"),
     path("<uuid:pk>/eraseserver", views.EraseServerView.as_view(), name="erase_server"),
     path("<uuid:pk>/download", views.DownloadEvidenceView.as_view(), name="download"),
+    path("tag/<str:pk>/delete", views.DeleteEvidenceTagView.as_view(), name="delete_tag"),
 ]

evidence/views.py

@@ -12,6 +12,7 @@ from django.views.generic.edit import (
     FormView,
 )
 
+from action.models import DeviceLog
 from dashboard.mixins import  DashboardView, Http403
 from evidence.models import SystemProperty, UserProperty, Evidence
 from evidence.forms import (
@@ -184,3 +185,35 @@ class EraseServerView(DashboardView, FormView):
     def get_success_url(self):
         success_url = reverse_lazy('evidence:details', args=[self.pk])
         return success_url
+
+
+class DeleteEvidenceTagView(DashboardView, DeleteView):
+    model = SystemProperty
+
+    def get_queryset(self):
+        # only those with 'CUSTOM_ID'
+        return SystemProperty.objects.filter(owner=self.request.user.institution, key='CUSTOM_ID')
+
+    def get(self, request, *args, **kwargs):
+        self.object = self.get_object()
+
+        message = _("<Deleted> Evidence Tag: {}").format(self.object.value) 
+        DeviceLog.objects.create(
+            snapshot_uuid=self.object.uuid,
+            event=message,
+            user=self.request.user,
+            institution=self.request.user.institution
+        )
+        self.object.delete()        
+
+        messages.info(self.request, _("Evicende Tag deleted successfully."))
+        return self.handle_success()
+
+    def handle_success(self):
+        return redirect(self.get_success_url())
+
+    def get_success_url(self):
+        return self.request.META.get(
+            'HTTP_REFERER', 
+            reverse_lazy('evidence:details', args=[self.object.uuid])
+        )