在 is_valid() 之前设置表单字段值 [英] Set form field value before is_valid()

问题描述

我在掌握如何执行此操作时遇到了一些麻烦.我已尽最大努力在 Google 上搜索，但运气不佳.

I'm having a bit of trouble grasping how to do this. I've put my best effort into searching Google without any luck.

我将从一些代码开始并解释我正在尝试做的事情:

I'll start with a bit of code and explain what I'm trying to do as I go:

class Action(models.Model):
    title = models.CharField(max_length=200)
    owner = models.ForeignKey(User, related_name='actions')
    created_by = models.ForeignKey(User, related_name='+', editable=False)
    modified_by = models.ForeignKey(User, related_name='+', editable=False)

class ActionForm(ModelForm):
    class Meta:
        model = Action

views.py

默认情况下，所有者有一个下拉字段.我有一个图标，允许用户在文本字段中输入新的用户名而不是所有者.我检查 owner_new 是否已提交，如果已提交，则创建该用户.然后我需要将 owner 字段设置为该值，以便 form.is_valid() 为 true.

views.py

By default, there is a dropdown field for owner. I have an icon that allows the user to enter a new username in a text field instead for owner. I check to see if owner_new was submitted and if so, create that user. I then need to set the owner field to that value so that form.is_valid() will be true.

def action_create(request):
    if request.method == 'POST':
        form = ActionForm(request.POST)
        # check if new user should be created
        if 'owner_new' in request.POST:
            # check if user already exists
            user = User.objects.get(username=request.POST.get('owner_new'))
            if not user:
                user = User.objects.create_user(request.POST.get('owner_new'))
            # HERE IS WHERE I'M STUMPED
            form.owner = user.id
        if form.is_valid(): # THIS FAILS BECAUSE form.owner ISN'T SET
            action = form.save(commit=False)
            action.created_by = request.user
            action.modified_by = request.user
            action.save()
            return redirect('action_register:index')
    else:
        form = ActionForm()
    return render(request, 'actions/create.html', {'form': form})

推荐答案

你可以试试这个:

def action_create(request):
    if request.method == 'POST':
        form = ActionForm(request.POST)
        # check if new user should be created
        if 'owner_new' in request.POST:
            # check if user already exists
            user, _ = User.objects.get_or_create(username=request.POST.get('owner_new'))                

            updated_data = request.POST.copy()
            updated_data.update({'owner': user}) 
            form = MyForm(data=updated_data) 

        if form.is_valid(): # THIS FAILS BECAUSE form.owner ISN'T SET
            action = form.save(commit=False)
            action.created_by = request.user
            action.modified_by = request.user
            action.save()
            return redirect('action_register:index')
    else:
        form = ActionForm()
    return render(request, 'actions/create.html', {'form': form})

更简洁的方法是:

将 required=False 添加到 owner 字段.现在，

add required=False to the owner field. Now,

if form.is_valid(): # THIS DOES NOT FAIL EVEN IF form.owner ISN'T SET
    action = form.save(commit=False)
    if 'owner_new' in request.POST:
        user, _ = User.objects.get_or_create(username=request.POST.get('owner_new'))                
        action.owner = user
    action.created_by = request.user
    action.modified_by = request.user
    action.save()
    return redirect('action_register:index')

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