forms.Form.auto_id

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 configurable, though, if you want to change the id convention or remove HTML id attributes and <label> tags entirely.

Use the auto_id argument to the Form constructor to control the id and label behavior. This argument must be True, False or a string.

If auto_id is False, then the form output will not include <label> tags nor id attributes:

>>> f = ContactForm(auto_id=False)
>>> print(f.as_table())
<tr><th>Subject:</th><td><input type="text" name="subject" maxlength="100" required /></td></tr>
<tr><th>Message:</th><td><input type="text" name="message" required /></td></tr>
<tr><th>Sender:</th><td><input type="email" name="sender" required /></td></tr>
<tr><th>Cc myself:</th><td><input type="checkbox" name="cc_myself" /></td></tr>
>>> print(f.as_ul())
<li>Subject: <input type="text" name="subject" maxlength="100" required /></li>
<li>Message: <input type="text" name="message" required /></li>
<li>Sender: <input type="email" name="sender" required /></li>
<li>Cc myself: <input type="checkbox" name="cc_myself" /></li>
>>> print(f.as_p())
<p>Subject: <input type="text" name="subject" maxlength="100" required /></p>
<p>Message: <input type="text" name="message" required /></p>
<p>Sender: <input type="email" name="sender" required /></p>
<p>Cc myself: <input type="checkbox" name="cc_myself" /></p>

If auto_id is set to True, then the form output will include <label> tags and will simply use the field name as its id for each form field:

>>> f = ContactForm(auto_id=True)
>>> print(f.as_table())
<tr><th><label for="subject">Subject:</label></th><td><input id="subject" type="text" name="subject" maxlength="100" required /></td></tr>
<tr><th><label for="message">Message:</label></th><td><input type="text" name="message" id="message" required /></td></tr>
<tr><th><label for="sender">Sender:</label></th><td><input type="email" name="sender" id="sender" required /></td></tr>
<tr><th><label for="cc_myself">Cc myself:</label></th><td><input type="checkbox" name="cc_myself" id="cc_myself" /></td></tr>
>>> print(f.as_ul())
<li><label for="subject">Subject:</label> <input id="subject" type="text" name="subject" maxlength="100" required /></li>
<li><label for="message">Message:</label> <input type="text" name="message" id="message" required /></li>
<li><label for="sender">Sender:</label> <input type="email" name="sender" id="sender" required /></li>
<li><label for="cc_myself">Cc myself:</label> <input type="checkbox" name="cc_myself" id="cc_myself" /></li>
>>> print(f.as_p())
<p><label for="subject">Subject:</label> <input id="subject" type="text" name="subject" maxlength="100" required /></p>
<p><label for="message">Message:</label> <input type="text" name="message" id="message" required /></p>
<p><label for="sender">Sender:</label> <input type="email" name="sender" id="sender" required /></p>
<p><label for="cc_myself">Cc myself:</label> <input type="checkbox" name="cc_myself" id="cc_myself" /></p>

If auto_id is set to a string containing the format character '%s', then the form output will include <label> tags, and will generate id attributes based on the format string. For example, for a format string 'field_%s', a field named subject will get the id value 'field_subject'. Continuing our example:

>>> f = ContactForm(auto_id='id_for_%s')
>>> print(f.as_table())
<tr><th><label for="id_for_subject">Subject:</label></th><td><input id="id_for_subject" type="text" name="subject" maxlength="100" required /></td></tr>
<tr><th><label for="id_for_message">Message:</label></th><td><input type="text" name="message" id="id_for_message" required /></td></tr>
<tr><th><label for="id_for_sender">Sender:</label></th><td><input type="email" name="sender" id="id_for_sender" required /></td></tr>
<tr><th><label for="id_for_cc_myself">Cc myself:</label></th><td><input type="checkbox" name="cc_myself" id="id_for_cc_myself" /></td></tr>
>>> print(f.as_ul())
<li><label for="id_for_subject">Subject:</label> <input id="id_for_subject" type="text" name="subject" maxlength="100" required /></li>
<li><label for="id_for_message">Message:</label> <input type="text" name="message" id="id_for_message" required /></li>
<li><label for="id_for_sender">Sender:</label> <input type="email" name="sender" id="id_for_sender" required /></li>
<li><label for="id_for_cc_myself">Cc myself:</label> <input type="checkbox" name="cc_myself" id="id_for_cc_myself" /></li>
>>> print(f.as_p())
<p><label for="id_for_subject">Subject:</label> <input id="id_for_subject" type="text" name="subject" maxlength="100" required /></p>
<p><label for="id_for_message">Message:</label> <input type="text" name="message" id="id_for_message" required /></p>
<p><label for="id_for_sender">Sender:</label> <input type="email" name="sender" id="id_for_sender" required /></p>
<p><label for="id_for_cc_myself">Cc myself:</label> <input type="checkbox" name="cc_myself" id="id_for_cc_myself" /></p>

If auto_id is set to any other true value – such as a string that doesn’t include %s – then the library will act as if auto_id is True.

By default, auto_id is set to the string 'id_%s'.

doc_Django
2016-10-09 18:36:51
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