Hi,
Recently, I am working almost with Akelos Framework.

I'm just saving null string('').
There seems to be a difference in the save when create and update.

When creating it, can you save the null string('')?
Because the NULL is not contained in input tag.
I hope,

<input name="item[value]" type="radio" value="" />

Item: id int, value string

<?php

function add(){
$this->Item->setAttribute(array('value' => ''));
$this->Item->save();
}
// value => null

function edit(){
$this->Item->setAttribute(array('id' => 1, 'value' => ''));
$this->Item->save();
}
// value => ''

?>

I'm sorry.
It is this description mistake.

$this->Item->setAttributes(array('value' => ''));

But, this result is the same.

The selected radiobutton cannot be released. Then, I adding selection 'no select' item.

Is it a specification that cannot add the null string(not NULL)? update is OK.

I'm just make a ActiveFormHelper extends FormHelper. It is automatically makes the form tags and the selection items from the database.

SelectItem Model: id int, value string, title string, category ... 1, 1, 1 minute 2, 3, 3 minute 3, 5, 5 minute 4, 10, 10 minute 5, null, no select <- I hope save null string(not NULL)

$this->SelectItem->setAttributes(array('value'=>'', 'title'=>'no select'));
$this->SelectItem->save();

Output from SelectItem.

class ActiveFormInstanceTag extends AkFormHelperInstanceTag
{
    function to_select_radio_tag($select_items, $options)
    {
        $select_radio = '';
        foreach ($select_items as $value => $text){
            $select_radio .= parent::to_radio_button_tag($value, $options).
            $text.'  ';
        }
        return $select_radio;
    }
}

Output html.

< html>
<input name="search[min]" type="radio" value="1" /> 1 minute
<input name="search[min]" type="radio" value="3" /> 3 minute
<input name="search[min]" type="radio" value="5" /> 5 minute
<input name="search[min]" type="radio" value="10" /> 10 minute
<input name="search[min]" type="radio" /> No select              <- if select this.
</html>

Result:

echo $this->params['search']['min']  =>  'on';

Thank you so much.