Form.errors.as_data() Returns a dict that maps fields to their original ValidationError instances. >>> f.errors.as_data() {'sender': [ValidationError(['Enter a valid email address.'])], 'subject': [ValidationError(['This field is required.'])]} Use this method anytime you need to identify an error by its code. This enables things like rewriting the error’s message or writing custom logic in a view when a given error is present. It can also be used to serialize the errors in a custo

Form.errors Access the errors attribute to get a dictionary of error messages: >>> f.errors {'sender': ['Enter a valid email address.'], 'subject': ['This field is required.']} In this dictionary, the keys are the field names, and the values are lists of Unicode strings representing the error messages. The error messages are stored in lists because a field can have multiple error messages. You can access errors without having to call is_valid() first. The form’s data will be valida

Form.cleaned_data Each field in a Form class is responsible not only for validating data, but also for “cleaning” it – normalizing it to a consistent format. This is a nice feature, because it allows data for a particular field to be input in a variety of ways, always resulting in consistent output. For example, DateField normalizes input into a Python datetime.date object. Regardless of whether you pass it a string in the format '1994-07-15', a datetime.date object, or a number of other for

Form.clean() Implement a clean() method on your Form when you must add custom validation for fields that are interdependent. See Cleaning and validating fields that depend on each other for example usage.

Form.changed_data The changed_data attribute returns a list of the names of the fields whose values in the form’s bound data (usually request.POST) differ from what was provided in initial. It returns an empty list if no data differs. >>> f = ContactForm(request.POST, initial=data) >>> if f.has_changed(): ... print("The following fields changed: %s" % ", ".join(f.changed_data))

Form.auto_id By default, the form rendering methods include: HTML id attributes on the form elements. The corresponding <label> tags around the labels. An HTML <label> tag designates which label text is associated with which form element. This small enhancement makes forms more usable and more accessible to assistive devices. It’s always a good idea to use <label> tags. The id attribute values are generated by prepending id_ to the form field names. This behavior is confi

Form.as_ul() as_ul() renders the form as a series of <li> tags, with each <li> containing one field. It does not include the <ul> or </ul>, so that you can specify any HTML attributes on the <ul> for flexibility: >>> f = ContactForm() >>> f.as_ul() '<li><label for="id_subject">Subject:</label> <input id="id_subject" type="text" name="subject" maxlength="100" required /></li>\n<li><label for="id_message">

Form.as_table() Finally, as_table() outputs the form as an HTML <table>. This is exactly the same as print. In fact, when you print a form object, it calls its as_table() method behind the scenes: >>> f = ContactForm() >>> f.as_table() '<tr><th><label for="id_subject">Subject:</label></th><td><input id="id_subject" type="text" name="subject" maxlength="100" required /></td></tr>\n<tr><th><label for="

Form.as_p() as_p() renders the form as a series of <p> tags, with each <p> containing one field: >>> f = ContactForm() >>> f.as_p() '<p><label for="id_subject">Subject:</label> <input id="id_subject" type="text" name="subject" maxlength="100" required /></p>\n<p><label for="id_message">Message:</label> <input type="text" name="message" id="id_message" required /></p>\n<p><label for="id_sender"&

Form.add_error(field, error) This method allows adding errors to specific fields from within the Form.clean() method, or from outside the form altogether; for instance from a view. The field argument is the name of the field to which the errors should be added. If its value is None the error will be treated as a non-field error as returned by Form.non_field_errors(). The error argument can be a simple string, or preferably an instance of ValidationError. See Raising ValidationError for best