Creating a delete button for each record

问题

I have a website which I have a bunch of records in the database. There are two fields, Name and Comment. models.py:

class Db_test(models.Model):
    name = models.CharField(max_length=50)
    comment = models.CharField(max_length=200)
    created = models.DateField(auto_now_add=True)
    modified = models.DateField(auto_now=True)

    class Meta:
        db_table = "db_test"

I have a page where all the records are displayed with a delete button next to it. My current page:

I have the following views.py (just the relevant function):

def delete(request):
    objects = Db_test.objects.all()
    items = []

    if request.method == "POST":
        print(int(list(request.POST)[-1]))
        objects[int(list(request.POST)[-1])].delete()

    for obj in objects:
        items.append([obj.name, obj.comment])

    return render(request, "models_test/delete.html", {"values": items})

The relevant DTL section:

{% for i in values %}
    <form method="POST">
        {% csrf_token %}
        <p>{{ forloop.counter }}: {{ i.0 }}<input type="submit" name={{forloop.counter0}} value="X"></p>
        <p>{{ i.1 }}</p>
    </form>
{% endfor %}

All this works fine except that it occasionally raises an error:

Traceback (most recent call last):
  File "/home/mooncheesez/Desktop/django_projects/test_project/venv/lib/python3.4/site-packages/django/core/handlers/base.py", line 149, in get_response
    response = self.process_exception_by_middleware(e, request)
  File "/home/mooncheesez/Desktop/django_projects/test_project/venv/lib/python3.4/site-packages/django/core/handlers/base.py", line 147, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/mooncheesez/Desktop/django_projects/test_project/venv/testproject/models_test/views.py", line 32, in delete
    print(int(list(request.POST)[-1]))
ValueError: invalid literal for int() with base 10: 'csrfmiddlewaretoken'

This line is the culprit:

objects[int(list(request.POST)[-1])].delete()

For some odd reason, request.POST only contains the csrf_token but not the submitted button. Note that it only happens occasionally too.

I searched around stackoverflow and I only found this post for deleting with checkboxes: Django: writing a view to delete an item with checkboxes

What do I do to avoid this? Are there better alternatives for what I am doing?

回答1:

I would suggest a different approach altogether.

In your view, pass the object itself:

objects = Db_test.objects.all()
return render(request, "models_test/delete.html", {"values": objects})

In your template:

{% for obj in object %}
    <form method="POST">
        {% csrf_token %}
        <p>{{ forloop.counter }}: {{ obj.name }}<input type="submit" name="delete_items" value="{{ obj.pk }}"></p>
        <p>{{ obj.comment }}</p>
    </form>
{% endfor %}

In your view again:

if request.method == "POST":
    # Fetch list of items to delete, by ID
    items_to_delete = request.POST.getlist('delete_items')
    # Delete those items all in one go
    Db_test.objects.filter(pk__in=items_to_delete).delete()

A few general comments:

There is nothing to be gained by passing a list like [obj.name, obj.comment] to your template. Just pass the object itself. This will be much easier to maintain.
Making changes based on natural database order is definitely not the right approach here - in fact it is dangerous and error-prone (e.g, what if items were added to the database while you were rendering the form?). Your database objects have a unique ID to identify them - use that.
request.POST is a dictionary. Converting it to a list doesn't make sense. If you supply a list of inputs all with the same name, you can use getlist() to fetch them.

来源：https://stackoverflow.com/questions/38418713/creating-a-delete-button-for-each-record

标签

python

django

post