Trying to create a dependent combobox in yii using ajax - php

Question

I am trying to create a dependent combobox system in my Yii application.
First combobox is populated with States and the second one is dynamically generated with ajax and renderPartial() method.
Code below:
View
<?php
$this->widget('ext.combobox.EJuiComboBox', array(
'model' => $adMulti,
'attribute' => 'state_id',
// data to populate the select. Must be an array.
'data' => CHtml::listData(State::model()->findAll(), 'id', 'name'),
'assoc' => true,
// options passed to plugin
'options' => array(
// JS code to execute on 'select' event, the selected item is
// available through the 'item' variable.
'onSelect' => 'getCities(item.value);',
// If false, field value must be present in the select.
// Defaults to true.
'allowText' => false,
),
// Options passed to the text input
'htmlOptions' => array(
'style' => 'height: 36px',
),
));
?>
<script type="text/javascript">
function getCities(state) {
$.ajax({
url: '<?php echo $this->createUrl('ad/ajaxCities'); ?>',
data: {state_name: state},
type: 'POST',
success: function (data) {
$('#city_id-carrier').html(data);
}
});
}
</script>
<div id="city_id-carrier" class="textboxes"></div>
AdController
public function actionAjaxCities()
{
$stateName = isset($_POST['state_name']) ? $_POST['state_name'] : FALSE;
if ($stateName) {
$state = State::model()->findByAttributes(array(
'name' => $stateName
));
$stateId = $state->id;
$cities = City::model()->findAllByAttributes(array(
'state_id' => $stateId
));
$this->renderPartial('_cities', array(
'cities' => $cities,
'stateId' => $stateId
), FALSE, TRUE
);
}
}
_cities.php
<?php
$this->widget('ext.combobox.EJuiComboBox', array(
'model' => AdMulti::model(),
'attribute' => 'city_id',
// data to populate the select. Must be an array.
'data' => CHtml::listData($cities, 'id', 'name'),
'assoc' => true,
// options passed to plugin
'options' => array(
// JS code to execute on 'select' event, the selected item is
// available through the 'item' variable.
// 'onSelect' => 'getLocalities(item.value);',
// If false, field value must be present in the select.
// Defaults to true.
'allowText' => false,
),
));
?>
The code is working and creating the combobox for the first time. But when I change the value in state combobox, something weird happens. A new combobox is created, but the values shown are still from the first combobox generated.
I am getting an error "TypeError: this.input is undefined" in Firebug Console.
I tried creating unique id for combobox using uniqid() but it isn't affecting the id of select element of the combobox.
If I change
$('#city_id-carrier').html(data)
to
$('#city_id-carrier').append(data)
it is working well but with multiple combobox generated.
Any ideas/suggestions to make this work?

Answer 1

I've found a solution to get this working. Instead of creating the combobox dynamically, place the combobox once and then populate it dynamically upon each request. Much like dependent dropdown.
A combobox is a combination of a dropdown and textbox. So, note down the id of the hidden dropdown and update it upon ajax update.
Code:
View:
<?php
$this->widget('ext.combobox.EJuiComboBox', array(
'model' => $adMulti,
'attribute' => 'state_id',
// data to populate the select. Must be an array.
'data' => CHtml::listData(State::model()->findAll(), 'id', 'name'),
'assoc' => true,
// options passed to plugin
'options' => array(
// JS code to execute on 'select' event, the selected item is
// available through the 'item' variable.
'onSelect' => 'getCities(item.value);',
// If false, field value must be present in the select.
// Defaults to true.
'allowText' => false,
),
));
?>
<script type="text/javascript">
function getCities(state) {
$.ajax({
url: '<?php echo $this->createUrl('ad/ajaxCities'); ?>',
data: {state_id: state},
type: 'POST',
beforeSend: function() {
$('#AdMulti_city_id_combobox').val(''); // emptying textbox in case a value is previously selected.
},
success: function (data) {
$('#AdMulti_city_id').html(data); // populating the hidden dropdown.
}
});
}
</script>
<?php
$this->widget('ext.combobox.EJuiComboBox', array(
'model' => $adMulti,
'attribute' => 'city_id',
// data to populate the select. Must be an array.
'data' => CHtml::listData(array(''), 'id', 'name'),
'assoc' => true,
// options passed to plugin
'options' => array(
'allowText' => false,
),
));
?>
AdController
public function actionAjaxCities()
{
$stateName = isset($_POST['state_id']) ? $_POST['state_id'] : FALSE;
if ($stateName) {
$state = State::model()->findByAttributes(array(
'name' => $stateName
));
$cities = City::model()->findAllByAttributes(array(
'state_id' => $state->id
));
$data = CHtml::listData($cities, 'id', 'name');
foreach ($data as $id => $name) {
echo CHtml::tag('option', array('value' => $id),
CHtml::encode($name), TRUE);
}
}
}