[html-formfu] combo box equivalent

[Carl Franks]

2008/8/31 Malcolm <mjh-formfu at liminalflux.net>:
> On Tuesday 26 August 2008, Carl Franks wrote:
>
>> >> > Is there a good way of doing a combo-box type element for a form? I've
>> >> > tried several variations, but so far I haven't found anything that
>> >> > doesn't end up requiring custom coding on the handler.
>> >> >
>> >> > This is the closest I've gotten, but their doesn't seem to be a way of
>> >> > enforcing the SingleValue constraint.
>
>> >> Because Multi is also a Field-element, when you add a constraint to
>> >> it, it doesn't get added to its children, unlike with other Block
>> >> elements.
>> >> If you add the constraint to one of the "country" fields, it should
>> >> work.
>
>> > The reason I tried it on the Multi element is that it didn't work on the
>> > member fields, as there's two child elements with the same name,
>> > SingleValue fails.
>
>> I've added a test for what I think you're describing, and it seems to work
>> okay. Can you have a look, and let me know if I'm not getting it?
>
>>
> http://code.google.com/p/html-formfu/source/browse/trunk/HTML-FormFu/t/elements/combo_box.t
>>
> http://code.google.com/p/html-formfu/source/browse/trunk/HTML-FormFu/t/elements/combo_box.yml
>
> If I plug in the contents of combo_box.yml into my form it doesn't work,
> so one of us is missing something.
>
> There are two issues with the combo_box.yml:
>
>  * If the form is filled with default values (which I do, using
> $form->model->default_values(...)), then both fields are filled out,
> resulting in a definite double, if identical, value if submitted unaltered.
>
>  * Even with no text in the text box, the SingleValue constraint is still
> failing.
>
>
> What I think is wrong with the test is that it's not actually doing a round
> trip through the generated html, which looks like this:
>
> <form action="" method="post">
>  <fieldset>
>  <div class="multi">
>   <span class="elements">
>    <select name="foo">
>     <option value="one">One</option>
>     <option value="two">Two</option>
>     <option value="three">Three</option>
>    </select>
>    <input name="foo" type="text" />
>   </span>
>  </div>
>  <div class="submit">
>    <input name="submit" type="submit" />
>  </div>
>  </fieldset>
> </form>
>
> When you submit that form, the text field has an empty value, not a
> non-existant one.
>
> There's also a missing test case of the "nothing selected from dropdown, but
> text in field" variant, as there's no available empty value from the
> dropdown.

I've added a new ComboBox element.

You can build it just as you would a Select field, using options(),
values() or value_range() - but under the hood it's really a Multi
element, like the Date field.

    type: ComboBox
    name: foo
    values: [yes, no]

If you set $field->default() to a value that's in the Select menu,
it'll set that Select option to selected="selected".
If you set $field->default() to an unknown value, it'll set the Text
field's value="$default".

It sets the Select's empty_first() to true - so there's always an empty option.

If you both select an option from the Select menu *and* fill in the
text field, it'll only use the value from the text field.

Like the Date field, you must always call $form->process() before
rendering the form.

Like any other field, you retrieve any submitted value with
$form->param_value('foo')

I've also added tests for Model-DBIC, to ensure it works with
options_from_model(), default_values and update().

Like the Date field, any constraints or other processors are added to
the ComboBox itself - not to its child elements.

I haven't yet put it into use in a real application, though I hope to
do so in the next week. - Let me know if you come across any problems,
or can think of any more tests I've missed.

Cheers,
Carl