Question

I am working on multilanguage form which is translated by i18n and I’ve occurred a problem.

When I use {{ form.as_p }} for generating forms and I provide invalid data to the form, the data provided earlier is not being cleaned from the form – and I want same behavior in my custom form which will have some fields translated.

This is my custom form:

<div class="">
{{ form.subject.errors }}
<input class="contact_form" id="id_subject"
type="text" name="subject"
onfocus="if(this.value=='{% trans "Title" %}') this.value=''"
value="{% trans "Title" %}"
maxlength="128" />
</div>

How I can modify its behavior so it wont clean the provided data after an error? And only fields which contained invalid dada sould get removed from the form.

I couldn’t find anything in the django docs for that issue.

Answer 1

Sander’s answer is correct, but if possible, you should try to avoid manually rendering your form fields in the template. In this case, you can set a initial value when you define the form:

from django.utils.translation import ugettext_lazy, ugettext as _

class MyForm(forms.Form):
    subject = Forms.CharField(initial=_("Title"), max_length=128))

You can then write some javascript to handle the onfocus event. Here’s an untested snippet, using the jQuery .focus() method.

<script type="text/javascript">
$(function() {
  $('#id_subject').focus(function() {
    if (this.value == '{{ form.subject.initial }}') {
      this.value = '';
    }
  });
});
</script>

You could also try passing the onfocus as a widget attribute. As you are using translatable strings, this might be a bit complicated – I think you might have to set the widget in the form’s __init__ method.