情况:
我在dropDownList 对象中指定“选定项目”时遇到了一些问题。我正在使用一个分组的 dropDownList,它有许多 optgroup 项目,每个项目都包含许多选择项目。挑战是试图找到一种方法来指定默认选定的项目,因为如前所述,每个项目都在一个 optgroup 中。
问题:
使用分组表单时如何设置默认选中项?或为什么下面的代码不起作用?
一些代码:
<?php
// retrieve the parent categories first
$parents = Categories::model()->findAllByAttributes(array('idCategoryParent'=>0));
// prepare an array to hold parent categories as optgroups, and their child categories as selectable items
$categories = array("Select a Category Below");
// prepare an array to hold the location of the selected item (if any)
$selectedItemInfo = array();
foreach($parents as $parent) {
// retrieve the sub categories for this parent category
$children = Categories::model()->cache(Yii::app()->findAllByAttributes(array('idCategoryParent'=>$parent->idCategory));
// prepare an array to temporarily hold all sub categories for this parent category
$categoriesChildren = array();
// iterate over sub categories
foreach($children as $child) {
// Assign the category name (label) to its numeric id
// Example. '10' => 'Coffee Mugs'
$categoriesChildren[$child->idCategory] = $child->label;
/**** Important part
* we may on occasion have an 'id' as a url parameter
* if 'id' isset, and
* if the current sub category idCategory matches 'id'
* mark this sub category as the item we want selected in our dropDownList
*/
if(isset($_GET['id']) && $child->idCategory == $_GET['id']){
// store the location of the current sub category
$selectedItemInfo[0] = $parent->label;
$selectedItemInfo[1] = $child->idCategory;
}
}
/*** Another Important part
* here we assign the whole child categories array
* as a single element in our categories array
* that can be accessed by the category name (label)
* of the parent category.
* Passing this entire $categories array to our
* dropDownList will make it render as a grouped
* dropDownList with the groups as optgroup items.
*/
// Example. 'Kitchenware' => {array}
$categories[$parentLabel] = $categoriesChildren;
}
?>
<?php
// get our selected item
/**** Remember
* The element $selectedItemInfo[0] holds our parent category's string name (label)
* The element $selectedItemInfo[1] holds our child category's id
*/
$selectedItem = $categories[$selectedItemInfo[0]][$selectedItemInfo[1]];
// create an options array to inform dropDownList of our selected item
$options = array('options'=>array($selectedItem=>array('selected'=>true)));
?>
//...
<div class="row">
<?php echo $form->labelEx($model,'idCategory'); ?>
<?php echo $form->dropDownList($model,'idCategory', $categories, $options); ?>
<?php echo $form->error($model,'idCategory'); ?>
</div>
//...