Reference The form rendering API

Reference The form rendering API

Form templates receive a context from Form.get_context(). By default, forms receive a dictionary with the following values: form: The bound form. fields: All bound fields, except the hidden fields. hidden_fields: All hidden bound fields.

Reference The form rendering API

Form.template_name To override form templates, you must use the TemplatesSetting renderer. Then overriding form templates works the same as overriding any other template in your project.

Topic guide Formsets

BaseFormSet has a couple of methods that are closely related to the ManagementForm, total_form_count and initial_form_count. total_form_count returns the total number of forms in this formset.

Topic guide Formsets

BaseFormSet provides an additional attribute empty_form which returns a form instance with a prefix of __prefix__ for easier use in dynamic forms with JavaScript.

Topic guide Working with forms

The HTML output when rendering a form is itself generated via a template. You can control this by creating an appropriate template file and setting a custom FORM_RENDERER to use that form_template_name site-wide.

How-to How to create custom model fields

To customize the form field used by ModelForm, you can override formfield(). The form field class can be specified via the form_class and choices_form_class arguments; the latter is used if the field has choices specified, the former otherwise.

Tutorial Writing your first Django app, part 4

Let’s update our poll detail template (“polls/detail.html”) from the last tutorial, so that the template contains an HTML <form> element: polls/templates/polls/detail.html A quick rundown: The above template displays a radio button for each question choice.

Tutorial Writing your first Django app, part 4

The above code checks for KeyError and redisplays the question form with an error message if choice isn’t given. F("votes") + 1 instructs the database to increase the vote count by 1.

Tutorial Writing your first Django app, part 7

By registering the Question model with admin.site.register(Question), Django was able to construct a default form representation. Often, you’ll want to customize how the admin form looks and works.

Reference

All of these fields and widgets are available from the django.contrib.postgres.forms module.

Reference The Forms API

Form.has_changed() Use the has_changed() method on your Form when you need to check if the form data has been changed from the initial data.

Reference The Forms API

Form.error_css_class Form.required_css_class It’s pretty common to style form rows and fields that are required or have errors. For example, you might want to present required form rows in bold and highlight errors in red.

Topic guide Working with forms

Topic guide Working with forms

Topic guide Working with forms

All form classes are created as subclasses of either django.forms.Form or django.forms.ModelForm. You can think of ModelForm as a subclass of Form.

Topic guide Working with forms

The distinction between Bound and unbound forms is important: An unbound form has no data associated with it. When rendered to the user, it will be empty or will contain default values.

Topic guide Working with forms

All you need to do to get your form into a template is to place the form instance into the template context.

Reference The Forms API

Form.fields You can access the fields of Form instance from its fields attribute: You can alter the field and BoundField of Form instance to change the way it is presented in the form: Beware not to alter the base_fields attribute …

Reference The Forms API

Form.default_renderer Specifies the renderer to use for the form. Defaults to None which means to use the default renderer specified by the FORM_RENDERER setting.