Radio buttons for custom post type categories from shortcode comma separated value

Question

I have created a custom post type. Everything works fine with a shortcode like this [program]

Now I would like to be able to create a shortcode like this

[program category="category_1,category_2,category_3"]

All those categories slugs from the shortcode have to appear in a radio button filter with the categorie name. Its working with only one category in the shortcode but once they're more and with commas it doesn't.

<?php function program_shortcode( $atts ) {
ob_start();

extract( shortcode_atts( array (
    'category' => '',
), $atts ) );

$options = array(
  'post_type' => 'program',
  'category_name' => $category,
  'posts_per_page' => -1); ?>

<div id="program-radiobuttons">
<?php $cat->slug = $category; ?>
<?php $categories = get_taxonomies(); ?>
<?php $checked = false ?><?php foreach ( $categories as $tax_type_key => $taxonomy ) { 
if ( $cat = get_term_by( 'slug', $cat->slug , $taxonomy ) ) {
break; }} ?>
<label><input type="radio" name="cat" value="<?php echo $cat->slug ?>"
<?php if (!$checked) echo ' checked="checked"' ?>>
<span><?php echo $cat->name; ?></span> </label>
<?php $checked = true ?></div>

Answer 1

Use the explode to split category attribute string into an array and then loop through it.

extract( shortcode_atts( array (
    'category' => '',
), $atts ) );

$taxonomies = explode(',', $category);
$taxonomy_name = 'TAXONOMY-SLUG';

foreach ( $taxonomies as $taxonomy ) {
    $cat = get_term_by( 'slug', $taxonomy , $taxonomy_name );
}