Django将字段错误添加到非模型表单字段

Question

谁能帮助我了解如何正确地将字段错误发送回 django 中未使用标准 django 表单验证过程的非模型表单字段？再次呈现表单时出现错误并且仍输入用户数据以进行更正和重新提交？

在模型级别验证的简单用户名字段的示例 html：

<!--form-->
                <form id="profile" class="small" method="POST" action="{% url 'profile' %}">
                {% csrf_token %}
                    <!--Username-->
                    <label for="username">Username <span style="font-style: italic;">(create a unique display name that will appear to other users on the site)</span></label>
                    <div class="input-group mb-3">
                        <div class="input-group-prepend">
                          <span class="input-group-text" id="username">@</span>
                        </div>
                        <input type="text" class="form-control" placeholder="Username" aria-label="Username" aria-describedby="username" name="username" value="{% if profile and profile.username is not None %}{{ profile.username }}{% endif %}">
                    </div>
                    <button type="submit" class="btn btn-primary" name="profile_form" value="profile_form">Save</button>
                </form>

查看

class ProfileView(View):

    def get(self, request, *args, **kwargs):
        # get request...


    def post(self, request, *args, **kwargs):
        if request.method == "POST":
            # check if profile_form submitted
            if 'profile_form' in request.POST:
                # get user form data
                profile_data = request.POST.dict()
                # get current user profile
                user_profile = Profile.objects.get(my_user=request.user)
                # check username entry against current
                if user_profile.username == profile_data['username']:
                    messages.success(request, "This is the current user.")
                else:
                    try:
                        # try to save the new username
                        user_profile.username = profile_data['username']
                        user_profile.save(update_fields=['username'])
                        messages.success(request, "Success: Username was updated.")
                    except:
                        # unique constraint error on username
                        # ERROR PROCESSING NEEDED
                        # Need to send error to form for user to correct and resubmit???
            
        # return get request to process any updated data
        return HttpResponseRedirect(reverse('profile'))

Answer 1

您应该使用处理表单数据的表单类，它还可以重新填充数据。

forms.py

class ProfileForm(forms.Form):
    username = forms.CharField(
        required=True,
        label="Username",
        help_text="(create a unique display name that will appear to other users on the site)",
    )

views.py

class ProfileView(View):

    def get(self, request, *args, **kwargs):
        # get request...


    def post(self, request, *args, **kwargs):
        if request.method == "POST":
            form = ProfileForm(request.POST)
            if form.is_valid():
                username = form.cleaned_data["username"]
                user_profile = Profile.objects.get(my_user=request.user)

                if user_profile.username == username:
                    messages.success(request, "This is the current user.")
                else:
                    try:
                        user_profile.username = username
                        user_profile.save(update_fields=["username"])
                        messages.success(request, "Success: Username was updated.")
                    except IntegrityError:
                        messages.error(request, "Error message which should be displayed")
                        return render(
                            request, "your_form.html", {"form": form}
                        )

        return HttpResponseRedirect(reverse('profile'))