Form.auto_id
By default, the form rendering methods include:
- HTML
idattributes 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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | >>> 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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | >>> 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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | >>> 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'.
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