Question

I am new to Django.
Now I have class defined below

PROPERTY_TYPE_CHOICE = [['1', 'Fixed (TODO)'],
                    ['2', 'Trajectory (TODO)'],
                    ['3', 'Error_Detecting'],
                    ['4', 'Error_Correcting']]
FIXED_TYPE_CHOICE = [['1', 'Prefix',
                      '2', 'Suffix']]

class UploadFileForm(forms.Form):
    # title = forms.CharField(max_length=50)
    automata_file  = forms.FileField(required = True)
    transducer_file = forms.FileField(required = True)
    property_type = forms.ChoiceField(choices=PROPERTY_TYPE_CHOICE,
                                      required=True)
    fixed_type = forms.ChoiceField(choices=FIXED_TYPE_CHOICE,
                                   required=True)
    debug_output = forms.BooleanField(required=False)

I have this PROPERTY_TYPE_CHOICE showed in the front html

<div class="fieldWrapper">
    {{ form.property_type.errors }}
    <label for="id_a">Select <u>a type</u> of property:</label>
    {{ form.property_type }}
</div>

and I want to show the FIXED_TYPE_CHOICE if I choose the first choice “Fixed (TODO)” in the PROPERTY_TYPE_CHOICE.
I read the docs about Django, and I think it may be implemented in this way:

<div class="fieldWrapper">
    {{ form.property_type.errors }}
    <label for="id_a">Select <u>a type</u> of property:</label>
    {{ form.property_type }}
</div>
{% if form.property_type=='1' %}
    <div class="fieldWrapper">
        {{ form.fixed_type.errors }}
        <label for="id_a">Select <u>a fixed type</u> of property:</label>
    {   { form.fixed_type }}
    </div>
{% endif %}

But I can’t do that.
What should I do? Thank you.

Answer 1

form.property_type is a BoundForm object, if you want to access its value you’ll need to use form.property_type.value

Which is why your comparison of {% if form.property_type=='1'} doesn’t work.

For more details see this page about 2/3rds of the way down, under the Customizing the Form Template section.

For updating without a page refresh, you’ll need Javascript like the following (make sure you also include the jQuery library (http://jquery.com/):

$("#property_type").change (function() {
    if($(this).val() == '1') {
        $("#fixed_type").show();
    } else {
        $("#fixed_type").hide();
    }
} )

And make sure that the give the dropdowns corresponding id attributes (id="property_type") for example.