Function input_update

pywebio/input.py:765–804

Update attributes of input field. This function can only be called in ``onchange`` callback of input functions. :param str name: The ``name`` of the target input item. Optional, default is the name of input field which triggers ``onchange`` :param spec: The input parameters need

(name: str = None, **spec)

def input_update(name: str = None, **spec):
    """Update attributes of input field.
    This function can only be called in ``onchange`` callback of input functions.

    :param str name: The ``name`` of the target input item.
       Optional, default is the name of input field which triggers ``onchange``
    :param spec: The input parameters need to be updated.
       Note that those parameters can not be updated:
       ``type``, ``name``, ``validate``, ``action``, ``code``, ``onchange``, ``multiple``

    An example of implementing dependent input items in an input group:

    .. exportable-codeblock::
        :name: input-update
        :summary: Dependent input items in input group

        country2city = {
            'China': ['Beijing', 'Shanghai', 'Hong Kong'],
            'USA': ['New York', 'Los Angeles', 'San Francisco'],
        }
        countries = list(country2city.keys())
        location = input_group("Select a location", [
            select('Country', options=countries, name='country',
                   onchange=lambda c: input_update('city', options=country2city[c])),
            select('City', options=country2city[countries[0]], name='city'),
        ])
        put_text(location)  # ..demo-only
    """
    task_id = get_current_task_id()
    k = 'onchange_trigger-' + task_id
    if k not in get_current_session().internal_save:
        raise RuntimeError("`input_update()` can only be called in `onchange` callback.")
    trigger_name = get_current_session().internal_save[k]

    if name is None:
        name = trigger_name

    attributes = parse_input_update_spec(spec)

    send_msg('update_input', dict(target_name=name, attributes=attributes))