我正在尝试多选，用户可以在模板中选择他们想要的类别。我想要的功能类似于“选择”字段类型，但仅通过类别来显示这些类别的帖子。
我已经获得了该页面所选选项的多选工作良好和高亮度，但在模板中，值不会使用以下方式显示：
<小时>
<?php var_dump(get_field(\'featured_tags\')); ?>
下面是自定义字段类型的完整代码：
<?php
class acf_Section extends acf_Field
{
/*--------------------------------------------------------------------------------------
*
* Constructor
*
* @author Elliot Condon
* @since 1.0.0
* @updated 2.2.0
*
*-------------------------------------------------------------------------------------*/
function __construct($parent)
{
parent::__construct($parent);
$this->name = \'section\';
$this->title = __("Section",\'acf\');
// filters (for all fields with choices)
add_filter(\'acf_save_field-select\', array($this, \'acf_save_field\'));
}
/*--------------------------------------------------------------------------------------
*
* create_field
*
* @author Elliot Condon
* @since 2.0.5
* @updated 2.2.0
*
*-------------------------------------------------------------------------------------*/
function create_field($field)
{
// vars
$defaults = array(
\'value\' => array(),
\'multiple\' => 0,
\'allow_null\' => 0,
\'choices\' => array(),
\'optgroup\' => 0,
);
$field = array_merge($defaults, $field);
// no choices
if(empty($field[\'choices\']))
{
echo \'<p>\' . __("No choices to choose from",\'acf\') . \'</p>\';
return false;
}
// multiple select
$multiple = \'\';
if( $field[\'multiple\'] )
{
// create a hidden field to allow for no selections
echo \'<input type="hidden" name="\' . $field[\'name\'] . \'" />\';
$multiple = \' multiple="multiple" size="5" \';
$field[\'name\'] .= \'[]\';
}
// html
echo \'<select id="\' . $field[\'id\'] . \'" class="\' . $field[\'class\'] . \'" name="\' . $field[\'name\'] . \'" \' . $multiple . \' >\';
$args = array(
\'orderby\' => \'name\',
\'parent\' => 0,
\'taxonomy\' => \'sections\',
);
$categories = get_categories($args);
$field[\'choices\'] = \'\';
foreach($categories as $cat) {
$selected = \'\';
if(is_array($field[\'value\']) && in_array($cat->term_id, $field[\'value\']))
{
// 2. If the value is an array (multiple select), loop through values and check if it is selected
$selected = \'selected="selected"\';
}
echo \'<option value="\'.$cat->term_id.\'" \'.$selected.\'>\'.$cat->name.\'</option>\';
}
echo \'</select>\';
}
/*--------------------------------------------------------------------------------------
*
* create_options
*
* @author Elliot Condon
* @since 2.0.6
* @updated 2.2.0
*
*-------------------------------------------------------------------------------------*/
function create_options($key, $field)
{
}
function update_value($post_id, $field, $value)
{
// save value
parent::update_value($post_id, $field, $value);
}
/*--------------------------------------------------------------------------------------
*
* pre_save_field
* - called just before saving the field to the database.
*
* @author Elliot Condon
* @since 2.2.0
*
*-------------------------------------------------------------------------------------*/
function acf_save_field( $field )
{
// vars
$defaults = array(
\'choices\' => \'\',
);
$args = array(
\'orderby\' => \'name\',
\'parent\' => 0,
\'taxonomy\' => \'sections\',
);
$categories = get_categories($args);
$field = array_merge($defaults, $field);
foreach($categories as $cat) {
$field[\'choices\'] .= $cat->term_id.\' : \'.$cat->name."\\n";
}
// check if is array. Normal back end edit posts a textarea, but a user might use update_field from the front end
if( is_array( $field[\'choices\'] ))
{
return $field;
}
// vars
$new_choices = array();
// explode choices from each line
if( $field[\'choices\'] )
{
// stripslashes ("")
$field[\'choices\'] = stripslashes_deep($field[\'choices\']);
if(strpos($field[\'choices\'], "\\n") !== false)
{
// found multiple lines, explode it
$field[\'choices\'] = explode("\\n", $field[\'choices\']);
}
else
{
// no multiple lines!
$field[\'choices\'] = array($field[\'choices\']);
}
// key => value
foreach($field[\'choices\'] as $choice)
{
if(strpos($choice, \' : \') !== false)
{
$choice = explode(\' : \', $choice);
$new_choices[trim($choice[0])] = trim($choice[1]);
}
else
{
$new_choices[trim($choice)] = trim($choice);
}
}
}
// update choices
$field[\'choices\'] = $new_choices;
// return updated field
return $field;
}
/*--------------------------------------------------------------------------------------
*
* get_value_for_api
*
* @author Elliot Condon
* @since 3.1.2
*
*-------------------------------------------------------------------------------------*/
function get_value_for_api($post_id, $field)
{
$value = parent::get_value($post_id, $field);
if($value == \'null\')
{
$value = false;
}
return $value;
}
}
?>
