Autocomplete task names

todo/__init__.py

@@ -8,3 +8,5 @@ __email__ = 'shacker@birdhouse.org'
 
 __url__ = 'https://github.com/shacker/django-todo'
 __license__ = 'BSD License'
+
+from . import check

todo/check.py

@@ -0,0 +1,12 @@
+from django.conf import settings
+from django.core.checks import Error, register
+
+@register()
+def dal_check(app_configs, **kwargs):
+    errors = []
+    missing_apps = {'dal', 'dal_select2'} - set(settings.INSTALLED_APPS)
+    for missing_app in missing_apps:
+        errors.append(
+            Error('{} needs to be in INSTALLED_APPS'.format(missing_app))
+        )
+    return errors

todo/models.py

@@ -19,6 +19,7 @@ class LockedAtomicTransaction(Atomic):
     transaction. Although this is the only way to avoid concurrency issues in certain situations, it should be used with
     caution, since it has impacts on performance, for obvious reasons...
     """
+
     def __init__(self, *models, using=None, savepoint=None):
         if using is None:
             using = DEFAULT_DB_ALIAS
@@ -29,14 +30,15 @@ class LockedAtomicTransaction(Atomic):
         super(LockedAtomicTransaction, self).__enter__()
 
         # Make sure not to lock, when sqlite is used, or you'll run into problems while running tests!!!
-        if settings.DATABASES[self.using]['ENGINE'] != 'django.db.backends.sqlite3':
+        if settings.DATABASES[self.using]["ENGINE"] != "django.db.backends.sqlite3":
             cursor = None
             try:
                 cursor = get_connection(self.using).cursor()
                 for model in self.models:
                     cursor.execute(
-                        'LOCK TABLE {table_name}'.format(
+                        "LOCK TABLE {table_name}".format(
-                            table_name=model._meta.db_table)
+                            table_name=model._meta.db_table
+                        )
                     )
             finally:
                 if cursor and not cursor.closed:
@@ -102,6 +104,9 @@ class Task(models.Model):
         super(Task, self).save()
 
     def merge_into(self, merge_target):
+        if merge_target.pk == self.pk:
+            raise ValueError("can't merge a task with self")
+
         # lock the comments to avoid concurrent additions of comments after the
         # update request. these comments would be irremediably lost because of
         # the cascade clause

todo/templates/todo/task_detail.html

@@ -2,6 +2,22 @@
 
 {% block title %}Task:{{ task.title }}{% endblock %}
 
+{% block extrahead %}
+<style>
+.select2 {
+    width: 100% !important;
+}
+
+.select2-container {
+    min-width: 0 !important;
+}
+</style>
+{{ form.media }}
+{{ merge_form.media }}
+{% endblock %}
+
+
+
 {% block content %}
   <div class="row">
     <div class="col-sm-8">
@@ -74,12 +90,14 @@
           </a>
         </li>
         <li class="list-group-item">
-        <h5>Merge task into</h5>
           <form action="" method="post">
             {% csrf_token %}
-          <div class="form-group">
+            {% for field in merge_form.visible_fields %}
-            <textarea class="form-control" name="merge-target" rows="3"></textarea>
+            <p>
-          </div>
+              {{ field.errors }}
+              {{ field }}
+            </p>
+            {% endfor %}
             <input class="btn btn-sm btn-primary" type="submit" name="merge_task_into" value="Merge task">
           </form>
         </li>

todo/urls.py

@@ -56,6 +56,11 @@ urlpatterns = [
         views.task_detail,
         name='task_detail'),
 
+    path(
+        'task/<int:task_id>/autocomplete/',
+        views.TaskAutocomplete.as_view(),
+        name='task_autocomplete'),
+
     path(
         'toggle_done/<int:task_id>/',
         views.toggle_done,

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  # noqa: F401
+from todo.views.task_detail import task_detail, TaskAutocomplete  # noqa: F401
 from todo.views.toggle_done import toggle_done  # noqa: F401

todo/views/task_detail.py

@@ -1,15 +1,46 @@
 import bleach
 import datetime
 
+from django import forms
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required, user_passes_test
 from django.core.exceptions import PermissionDenied
 from django.http import HttpResponse
-from django.shortcuts import get_object_or_404, redirect, render
+from django.shortcuts import get_object_or_404, redirect, render, redirect
+from django.urls import reverse
+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 dal import autocomplete
+
+
+def user_can_read_task(task, user):
+    return task.task_list.group in user.groups.all() or user.is_staff
+
+
+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
@@ -23,14 +54,29 @@ def task_detail(request, task_id: int) -> HttpResponse:
 
     # 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 task.task_list.group not in request.user.groups.all() and not request.user.is_staff:
+    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.method == "POST":
+        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
 
-    if request.POST.get("merge_task_into"):
-        target_task_id = int(request.POST.get("merge-target"))
-        merge_target = Task.objects.get(pk=target_task_id)
             task.merge_into(merge_target)
-        return redirect("todo:task_detail", task_id=merge_target.id)
+            return redirect(reverse("todo:task_detail", kwargs={"task_id": task_id}))
+    else:
+        merge_form = MergeForm()
 
     # Save submitted comments
     if request.POST.get("add_comment"):
@@ -46,12 +92,17 @@ 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.")
+        messages.success(
+            request, "Comment posted. Notification email sent to thread participants."
+        )
 
     # Save task edits
     if request.POST.get("add_edit_task"):
         form = AddEditTaskForm(
-            request.user, request.POST, instance=task, initial={"task_list": task.task_list}
+            request.user,
+            request.POST,
+            instance=task,
+            initial={"task_list": task.task_list},
         )
 
         if form.is_valid():
@@ -60,10 +111,14 @@ def task_detail(request, task_id: int) -> HttpResponse:
             item.save()
             messages.success(request, "The task has been edited.")
             return redirect(
-                "todo:list_detail", list_id=task.task_list.id, list_slug=task.task_list.slug
+                "todo:list_detail",
+                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})
+        form = AddEditTaskForm(
+            request.user, instance=task, initial={"task_list": task.task_list}
+        )
 
     # Mark complete
     if request.POST.get("toggle_done"):
@@ -78,6 +133,12 @@ def task_detail(request, task_id: int) -> HttpResponse:
     else:
         thedate = datetime.datetime.now()
 
-    context = {"task": task, "comment_list": comment_list, "form": form, "thedate": thedate}
+    context = {
+        "task": task,
+        "comment_list": comment_list,
+        "form": form,
+        "merge_form": merge_form,
+        "thedate": thedate,
+    }
 
     return render(request, "todo/task_detail.html", context)