How to update db record from Django form

Question

I am a newbie to Django, so this might sound like a stupid question, but please bear with me. I have created a form for inserting records into my db, and now I am trying to use this same form for updating records. But it does not seem to work correctly. Here is my code.

1. I can't figure out how to dynamically pass the id of the record from HTML. When I hardcode the id, everything is ok. Here's the code. I tried action="/task_list/update_task/{{ id }} /" which does not work and "/update_task//" appears in URL, causing Django to raise error message because no view is found. Ideally, I would like to pass the Django-s embedded id, and not the id from the model, otherwise I have to manually include id = models.IntegerField(primary_key=True) command in my model and exclude it from the form which does not seem to be "best practice", given that Django has its own ids.
2. I expected Django to automacically fill up the textboxes by the correponding values of the selected records, but the they are rendered blank (as a result, I have to fill all the textboxes, even if I want to change one of the fields). Here' my view.

Here is the code: URL:

url(r'^task_list/update_task/(?P<task_id>\d+)/$',task_views.updateTask),

View:

def updateTask(request, task_id):
    #cur_usr_sale_point = PersonUnique.objects.filter(employees__employeeuser__auth_user = request.user.id).values_list('agreementemployees__agreement_unique__sale_point_id',flat=True)
    selected_task = Tasks.objects.get(id=task_id)    

    if request.method == 'POST':
        task_form = TaskForm(request.POST,instance=task_id)
        if task_form.is_valid():
            task_form.save();
            taskTable = Tasks.objects.all()
            return render_to_response('task_management/task_list.html',{'createTask_form':task_form, 'taskTable': taskTable},context_instance=RequestContext(request))
    else:
        taskTable = Tasks.objects.all()
        task_form =   TaskForm()   
    return render_to_response('task_management/task_list.html',{'createTask_form':task_form, 'taskTable': taskTable},context_instance=RequestContext(request))

The Django form

class TaskForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super(TaskForm, self).__init__(*args, **kwargs)
        for field_name, field in self.fields.items():
            field.error_messages={'required':  'Придется не поленится и заполнить это поле...'}
            field.widget.attrs['cl

class Meta:
        model=Tasks
        fields = '__all__'
        exclude=['id']

The template:

{% for task in taskTable %}
    <tr>
        <td onclick = "updateTaskWindow()"> <span style="display:block;" class="glyphicon glyphicon-pencil"></span></a>
        </td>
        <td>{{task.description_short}}</td>
     </tr>
{% endfor %}

The Bootstrap modal window which should be used for updating:

<form class="modal fade" id="updateTaskWindow" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" action="/task_list/update_task/{{ pk }}/" method="post">{% csrf_token %}
  <div class="modal-dialog modal-lg form-horizontal" role="form">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <h4 class="modal-title" id="exampleModalLabel">Обновить задачу</h4>
      </div>
      <div class="modal-body" style="font-size: smaller">
        {{ createTask_form.as_p }}  
      </div>
      <div class="modal-footer">    
        <input class="btn btn-default btn-sm" type="submit" value="Обновить"/>
      </div>
    </div>
  </div>
</form>

The model:

class Tasks(models.Model):
    id = models.IntegerField(primary_key=True)
    description_short = models.CharField(max_length=500)
    description_full = models.TextField()
    status = models.ForeignKey(TaskStatus, on_delete=models.CASCADE)
    type = models.ForeignKey(TaskType, on_delete=models.CASCADE)
    date_start = models.DateTimeField(blank=True, null=True)
    date_end = models.DateTimeField(blank=True, null=True)
    is_important = models.IntegerField(blank=True, null=True)
    effective_from = models.DateTimeField(blank=True, null=True)
    effective_to = models.DateTimeField()

    class Meta:
        managed = False
        db_table = 'tasks'

And the JS:

var updateTaskWindow = function() {
    $('#updateTaskWindow').modal('show');
}

I spent hours trying to implement this, but did not succeed. Please help !!!

Answer 1

First change you form to have inputs for each field of your model, read about forms here

then do something like the following

if request.method == 'POST':
    task_form = TaskForm(request.POST,instance=selected_task )
    if task_form.is_valid():
        # inside your model instance add each field with the wanted value for it
        newrecord = Tasks(name=task_form.cleaned_data['name']);
        task_form.save();