Make task merging optional

todo/check.py

@@ -1,8 +1,15 @@
-from django.conf import settings
 from django.core.checks import Error, register
 
+# the sole purpose of this warning is to prevent people who have
+# django-autocomplete-light installed but not configured to start the app
 @register()
 def dal_check(app_configs, **kwargs):
+    from django.conf import settings
+    from todo.features import HAS_AUTOCOMPLETE
+
+    if not HAS_AUTOCOMPLETE:
+        return
+
     errors = []
     missing_apps = {'dal', 'dal_select2'} - set(settings.INSTALLED_APPS)
     for missing_app in missing_apps:

todo/features.py

@@ -0,0 +1,11 @@
+HAS_AUTOCOMPLETE = True
+try:
+    import dal
+except ImportError:
+    HAS_AUTOCOMPLETE = False
+
+HAS_TASK_MERGE = False
+if HAS_AUTOCOMPLETE:
+    import dal.autocomplete
+    if getattr(dal.autocomplete, 'Select2QuerySetView', None) is not None:
+        HAS_TASK_MERGE = True

todo/mail/delivery.py

@@ -18,3 +18,4 @@ def _declare_backend(backend_path):
 
 smtp_backend = _declare_backend('django.core.mail.backends.smtp.EmailBackend')
 console_backend = _declare_backend('django.core.mail.backends.console.EmailBackend')
+locmem_backend = _declare_backend('django.core.mail.backends.locmem.EmailBackend')

todo/templates/todo/include/task_edit.html

@@ -2,8 +2,7 @@
 
 <form action="" name="add_task" method="post">
   {% csrf_token %}
-
-  <div id="AddEditTask" class="mt-3">
+  <div class="mt-3">
     <div class="form-group">
       <label for="id_title" name="title">Task</label>
       <input type="text" class="form-control" id="id_title" name="title" required placeholder="Task title"

todo/templates/todo/list_detail.html

@@ -10,7 +10,9 @@
       data-toggle="collapse" data-target="#AddEditTask">Add Task</button>
 
     {# Task edit / new task form #}
+    <div id="AddEditTask" class="collapse">
       {% include 'todo/include/task_edit.html' %}
+    </div>
     <hr />
   {% endif %}
 

todo/templates/todo/task_detail.html

@@ -93,6 +93,7 @@
   <div id="TaskEdit" class="collapse">
     {# Task edit / new task form #}
     {% include 'todo/include/task_edit.html' %}
+    {% if merge_form is not None %}
     <form action="" method="post">
       <div class="card border-danger">
       <div class="card-header">Merge task</div>
@@ -111,6 +112,7 @@
       </div>
       </div>
     </form>
+    {% endif %}
   </div>
 
   <div class="mt-3">

todo/urls.py

@@ -1,11 +1,12 @@
 from django.urls import path
 
 from todo import views
-
+from todo.features import HAS_TASK_MERGE
 app_name = 'todo'
 
-urlpatterns = [
+from django.conf import settings
 
+urlpatterns = [
     path(
         '',
         views.list_lists,
@@ -55,12 +56,19 @@ urlpatterns = [
         'task/<int:task_id>/',
         views.task_detail,
         name='task_detail'),
+]
 
+if HAS_TASK_MERGE:
+    # ensure autocomplete is optional
+    from todo.views.task_autocomplete import TaskAutocomplete
+    urlpatterns.append(
         path(
             'task/<int:task_id>/autocomplete/',
-        views.TaskAutocomplete.as_view(),
-        name='task_autocomplete'),
+            TaskAutocomplete.as_view(),
+            name='task_autocomplete')
+    )
 
+urlpatterns.extend([
     path(
         'toggle_done/<int:task_id>/',
         views.toggle_done,
@@ -75,4 +83,4 @@ urlpatterns = [
         'search/',
         views.search,
         name="search"),
-]
+])

todo/utils.py

@@ -23,6 +23,10 @@ def staff_check(user):
         return True
 
 
+def user_can_read_task(task, user):
+    return task.task_list.group in user.groups.all() or user.is_staff
+
+
 def todo_get_backend(task):
     '''returns a mail backend for some task'''
     mail_backends = getattr(settings, "TODO_MAIL_BACKENDS", None)
@@ -148,8 +152,9 @@ def send_email_to_thread_participants(task, msg_body, user, subject=None):
         for ca in commenters
         if ca.author is not None
     )
-    for user_email in (task.created_by.email, task.assigned_to.email):
-        recip_list.add(user_email)
+    for related_user in (task.created_by, task.assigned_to):
+        if related_user is not None:
+            recip_list.add(related_user.email)
     recip_list = list(m for m in recip_list if m)
 
     todo_send_mail(user, task, email_subject, email_body, recip_list)

todo/views/__init__.py

@@ -6,5 +6,5 @@ from todo.views.list_detail import list_detail  # noqa: F401
 from todo.views.list_lists import list_lists  # noqa: F401
 from todo.views.reorder_tasks import reorder_tasks  # noqa: F401
 from todo.views.search import search  # noqa: F401
-from todo.views.task_detail import task_detail, TaskAutocomplete  # noqa: F401
+from todo.views.task_detail import task_detail  # noqa: F401
 from todo.views.toggle_done import toggle_done  # noqa: F401

todo/views/task_autocomplete.py

@@ -0,0 +1,29 @@
+from dal import autocomplete
+from django.contrib.auth.decorators import login_required
+from django.core.exceptions import PermissionDenied
+from django.shortcuts import get_object_or_404
+from django.utils.decorators import method_decorator
+from todo.models import Task
+from todo.utils import user_can_read_task
+
+
+class TaskAutocomplete(autocomplete.Select2QuerySetView):
+    @method_decorator(login_required)
+    def dispatch(self, request, task_id, *args, **kwargs):
+        self.task = get_object_or_404(Task, pk=task_id)
+        if not user_can_read_task(self.task, request.user):
+            raise PermissionDenied
+
+        return super().dispatch(request, task_id, *args, **kwargs)
+
+    def get_queryset(self):
+        # Don't forget to filter out results depending on the visitor !
+        if not self.request.user.is_authenticated:
+            return Task.objects.none()
+
+        qs = Task.objects.filter(task_list=self.task.task_list).exclude(pk=self.task.pk)
+
+        if self.q:
+            qs = qs.filter(title__istartswith=self.q)
+
+        return qs

todo/views/task_detail.py

@@ -12,77 +12,19 @@ from django.utils.decorators import method_decorator
 
 from todo.forms import AddEditTaskForm
 from todo.models import Comment, Task
-from todo.utils import send_email_to_thread_participants, toggle_task_completed, staff_check
-from todo.utils import send_email_to_thread_participants, toggle_task_completed
+from todo.utils import send_email_to_thread_participants, toggle_task_completed, staff_check, user_can_read_task
+from todo.features import HAS_TASK_MERGE
+
+
+if HAS_TASK_MERGE:
     from dal import autocomplete
+    from todo.views.task_autocomplete import TaskAutocomplete
 
 
-def user_can_read_task(task, user):
-    return task.task_list.group in user.groups.all() or user.is_staff
+def handle_add_comment(request, task):
+    if not request.POST.get("add_comment"):
+        return
 
-
-class TaskAutocomplete(autocomplete.Select2QuerySetView):
-    @method_decorator(login_required)
-    def dispatch(self, request, task_id, *args, **kwargs):
-        self.task = get_object_or_404(Task, pk=task_id)
-        if not user_can_read_task(self.task, request.user):
-            raise PermissionDenied
-
-        return super().dispatch(request, task_id, *args, **kwargs)
-
-    def get_queryset(self):
-        # Don't forget to filter out results depending on the visitor !
-        if not self.request.user.is_authenticated:
-            return Task.objects.none()
-
-        qs = Task.objects.filter(task_list=self.task.task_list).exclude(pk=self.task.pk)
-
-        if self.q:
-            qs = qs.filter(title__istartswith=self.q)
-
-        return qs
-
-
-@login_required
-@user_passes_test(staff_check)
-def task_detail(request, task_id: int) -> HttpResponse:
-    """View task details. Allow task details to be edited. Process new comments on task.
-    """
-
-    task = get_object_or_404(Task, pk=task_id)
-    comment_list = Comment.objects.filter(task=task_id)
-
-    # Ensure user has permission to view task. Admins can view all tasks.
-    # Get the group this task belongs to, and check whether current user is a member of that group.
-    if not user_can_read_task(task, request.user):
-        raise PermissionDenied
-
-    class MergeForm(forms.Form):
-        merge_target = forms.ModelChoiceField(
-            queryset=Task.objects.all(),
-            widget=autocomplete.ModelSelect2(
-                url=reverse("todo:task_autocomplete", kwargs={"task_id": task_id})
-            ),
-        )
-
-    # Handle task merging
-    if request.POST.get("merge_task_into"):
-        merge_form = MergeForm(request.POST)
-        if merge_form.is_valid():
-            merge_target = merge_form.cleaned_data["merge_target"]
-            if not user_can_read_task(merge_target, request.user):
-                raise PermissionDenied
-
-            task.merge_into(merge_target)
-            return redirect(reverse(
-                "todo:task_detail",
-                kwargs={"task_id": merge_target.pk}
-            ))
-    else:
-        merge_form = MergeForm()
-
-    # Save submitted comments
-    if request.POST.get("add_comment"):
     Comment.objects.create(
         author=request.user,
         task=task,
@@ -95,12 +37,63 @@ def task_detail(request, task_id: int) -> HttpResponse:
         request.user,
         subject='New comment posted on task "{}"'.format(task.title),
     )
+
     messages.success(
         request, "Comment posted. Notification email sent to thread participants."
     )
 
+
+@login_required
+@user_passes_test(staff_check)
+def task_detail(request, task_id: int) -> HttpResponse:
+    """View task details. Allow task details to be edited. Process new comments on task.
+    """
+
+    task = get_object_or_404(Task, pk=task_id)
+    comment_list = Comment.objects.filter(task=task_id).order_by('-date')
+
+    # Ensure user has permission to view task. Admins can view all tasks.
+    # Get the group this task belongs to, and check whether current user is a member of that group.
+    if not user_can_read_task(task, request.user):
+        raise PermissionDenied
+
+    # Handle task merging
+    if not HAS_TASK_MERGE:
+        merge_form = None
+    else:
+        class MergeForm(forms.Form):
+            merge_target = forms.ModelChoiceField(
+                queryset=Task.objects.all(),
+                widget=autocomplete.ModelSelect2(
+                    url=reverse("todo:task_autocomplete", kwargs={"task_id": task_id})
+                ),
+            )
+
+        # Handle task merging
+        if not request.POST.get("merge_task_into"):
+            merge_form = MergeForm()
+        else:
+            merge_form = MergeForm(request.POST)
+            if merge_form.is_valid():
+                merge_target = merge_form.cleaned_data["merge_target"]
+            if not user_can_read_task(merge_target, request.user):
+                raise PermissionDenied
+
+            task.merge_into(merge_target)
+            return redirect(reverse(
+                "todo:task_detail",
+                kwargs={"task_id": merge_target.pk}
+            ))
+
+    # Save submitted comments
+    handle_add_comment(request, task)
+
     # Save task edits
-    if request.POST.get("add_edit_task"):
+    if not request.POST.get("add_edit_task"):
+        form = AddEditTaskForm(
+            request.user, instance=task, initial={"task_list": task.task_list}
+        )
+    else:
         form = AddEditTaskForm(
             request.user,
             request.POST,
@@ -118,10 +111,6 @@ def task_detail(request, task_id: int) -> HttpResponse:
                 list_id=task.task_list.id,
                 list_slug=task.task_list.slug,
             )
-    else:
-        form = AddEditTaskForm(
-            request.user, instance=task, initial={"task_list": task.task_list}
-        )
 
     # Mark complete
     if request.POST.get("toggle_done"):