无法更新CharField-Django

Question

First of all I'm glad to be here, I read you lately and i found useful answers here.
This is my first post so please be kind with me, I'm a newbie in programming.

So, I'm writing my 1st web application in Django - a todo app and I don't know how to write the function that does this this. I found something in Django docs and in other related discussions but it doesn't work.

Here's my code:

#models.py

class Task(models.Model):
user = models.ForeignKey(User)
task = models.CharField(max_length=200)
initialized_at = models.DateTimeField(auto_now_add=True)
due_date = models.DateField(default=datetime.now)
done = models.BooleanField(default=False)

def __unicode__(self):
    return self.task

#views.py
def edit_task(request, id):
if request.method == 'POST':
    task_to_edit = Task.objects.get(pk=task_id)
    form = TaskForm(request.POST, instance=task_to_edit)
    form.save()
    if form.is_valid():
        task_to_edit = form.save()
    return HttpResponseRedirect('/')
else:
    form = TaskForm()
return render(request, 'todo/edit_task.html', {'form': form})

#urls.py
url(r'^edit_task/(?P<task_id>\w+)/$', 'todo.views.edit_task')

#edit_task.html
{% block content %}
<form action="/edit_task/" method="post">{% csrf_token %}
    {{ form.as_p }}
    <input type="submit" value="Submit" />
</form>
{% endblock content %}

When I submit the updated form I get this error:

Page not found (404)
Request Method:     POST
Request URL:    hxxp://127.0.0.1:8000/edit_task/

Using the URLconf defined in jbz.urls, Django tried these URL patterns, in this order:

^admin/
^$ [name='index']
^(?P<task_id>\d+)/$
^(?P<task_id>\d+)/$
^add-task/$
^delete-task/(?P<task_id>\w+)/$
^edit_task/(?P<id>\w+)/$
^done/(?P<task_id>\d*)/$

The current URL, edit_task/ , didn't match any of these.

and the root urls.py looks like:

url(r'', include('todo.urls'))

Answer 1

#edit_task.html
{% block content %}
<form action="/edit_task/{{task.id}}" method="post">{% csrf_token %}
    {{ form.as_p }}
    <input type="submit" value="Submit" />
</form>
{% endblock content %}

Notice how I added {{task.id}} expression in <form action="/edit_task/{{task.id}}" method="post">

IMPORTANT NOTE: Substitute {{task.id}} to whatever variable accomplishes this in your template.

The reason why you get the error is because edit_task/ is not getting the other part, task_id to match the regular expression:

url(r'^edit_task/(?P<task_id>\w+)/$', 'todo.views.edit_task')

UPDATE: Also your edit_task view has potential errors as well>

def edit_task(request, id):
    task_to_edit = Task.objects.get(pk=id)
    if request.method == 'POST':
        form = TaskForm(request.POST, instance=task_to_edit)
        form.save()
        if form.is_valid():
            task_to_edit = form.save()
        return HttpResponseRedirect('/')
else:
    form = TaskForm(instance=task_to_edit)
# you don't pass any task variable to the view so the form view
# won't know which task to edit, you'll have to handle that
return render(request, 'todo/edit_task.html', {'form': form, 'task':task_to_edit})

Note: I corrected the code in the view a little. Now the task_to_edit is passed also to the Form to fill the fields when the view is requested via GET . Notice that in order to access to this view, the url in the browser should look like this http://www.example.com/edit_task/2

If other wise you try to access http://www.example.com/edit_task without passing the id you'll get Error 404 .

Hope this helps!

Answer 2

I think your pattern for edit task expects an id - task name. Try changing your URL pattern:

'^edit_task/(?P<task_id>\w+)/$'

to

'^edit_task/$'

or providing the task id that you want to edit.

Answer 3

Just add name space to your url and according update your template.

#urls.py
url(r'^edit_task/(?P<task_id>\w+)/$', 'todo.views.edit_task', name= "edit_task")

#edit_task.html
{% block content %}
<form action="{% url 'edit_task' task_id %}" method="post">{% csrf_token %}
    {{ form.as_p }}
    <input type="submit" value="Submit" />
</form>
{% endblock content %}