Django如何使用Modelform显示错误消息

Question

I use django modelform to save data,
I use ajax ,so it won't redirect to other page. when submit,the view create_post will deal with it.

But I have a question,if I type 'abc' in the email's filed and submit.
I know it won't pass the validation,But it doesn't print the error message to let the user know where is the mistake.
How can I edit to reach it? Please guide me. Thank you .

[EDIT] when I edit to this return render(request, "zh_tw/maininfo.html#5thpage",{form: 'form'}) Now if I type 'abc' in email field,the post is 200 ok.
But when it render back to this page, it will alert 'ERROR!'
it seems like it run this part in ajax: error: function(ts){ alert('ERROR!!!'); window.location.reload(); }, error: function(ts){ alert('ERROR!!!'); window.location.reload(); },

template/main.html

<script type="text/javascript">
$( document ).ready(function() {
    $.ajaxSetup({
        data: { csrfmiddlewaretoken: '{{ csrf_token }}' },
    });

    // Submit post on submit
    $('#create_post').on('submit', function(event){
        event.preventDefault();
        var name = $("#name").val();
        var email = $("#email").val();
        var message = $("#message").val();

        $.ajax({
            url: '{% url 'core:create_post' %}',
            data: { "name":name,"email":email,"message":message,},
            type: 'POST',
            async: false,
            dataType: 'json',
            error: function(ts){
                alert('ERROR!!!');
                window.location.reload();
            },
            success: function(dataArr){
                if(dataArr == 2){
                    alert('success!');
                    window.location.reload();
                }else{
                    alert('something wrong!');
                    window.location.reload();
                }
            }
        });
    });
});
</script>

<div class="section" id="contact">
    <div class="message">
        <form action="." method="POST" id="create_post">
        {% csrf_token %}
        {{ form.non_field_errors }}
        {{ form }}
        <div>
            <input type="text" name="FirstName" id="name" placeholder="your name">
            <input type="text" name="Email" id="email" placeholder="your email">
        </div>
        <textarea placeholder="talk?" name = "Message" id="message"></textarea>
        <br>
        <button type="submit" value="Submit" id="submit">submit</button>
        </form>
    </div>
</div>

views.py

def maininfo(request):
    # return render(request, 'english/maininfo.html',)
    return render(request, 'zh_tw/maininfo.html',)


def create_post(request):
    if request.method == 'POST':
        form = MessageForm(request.POST)
        if form.is_valid():
            obj = form.save(commit=False)
            obj.ip = request.META['REMOTE_ADDR']
            obj.save()
            return HttpResponse(2)
        return render(request, "zh_tw/maininfo.html#5thpage",{form: 'form'})

Answer 1

This will render form errors and form non-field errors in case you have them.

<div class="section" id="contact">
    <div class="message">
        <form action="." method="POST" id="create_post">
        {% csrf_token %}
        {{ form.non_field_errors }}
        {{ form }}
        <button type="submit" value="Submit" id="submit">submit</button>
        </form>
    </div>
</div>

This is a bit improved view:

def create_post(request):
    form = MessageForm(request.POST or None)
    if form.is_valid():
        obj = form.save(commit=False)
        obj.ip = request.META['REMOTE_ADDR']
        obj.save()
    return render_to_response(request, template="your_template.html", context={form: 'form'})