How to add category option to shortcode - php

Question

I'm new to creating wordpress shortcodes and have one just about working the way I want. Missing something specific. Currently I am able to put the following on any page - [children] and it pulls a query of all posts from the custom post type "children" I would like to add the option to add the category id within the shortcode - something like [children category="8"] Here is the code I have so far:
add_shortcode( 'children', 'display_custom_post_type' );
function display_custom_post_type(){
$args = array(
'post_type' => 'children',
'post_status' => 'publish',
'orderby' => 'title',
'order' => 'ASC',
);
$string = '';
$query = new WP_Query( $args );
if( $query->have_posts() ){
while( $query->have_posts() ){
$query->the_post();
$string .= '<div id="childWrapper"><div id="childImage">' . get_the_post_thumbnail() . '</div><div style="clear: both;"></div><div id="childName">' . get_the_title() . '</div><div style="clear: both;"></div></div>';
}
}
wp_reset_postdata();
return $string;
}
Secondary - is it possible for it to show posts in multiple categories, but only where the posts are in each of the categories. For example showing a list of children, who fall under a category for critical care and surgery needed.
Any help would be greatly appreciated.

Answer 1

You should refer Shortcode function from WordPress Codex. Assuming your taxonomy name is category, I made some changes in your current code it should work as per your requirements.
/**
* [children category="5,7,8"]
*/
add_shortcode( 'children' , 'display_custom_post_type' );
function display_custom_post_type($atts) {
$atts = shortcode_atts( array(
'category' => ''
), $atts );
//If category is multiple: 8,9,3
$categories = explode(',' , $atts['category']);
$args = array(
'post_type' => 'children',
'post_status' => 'publish',
'orderby' => 'title',
'order' => 'ASC',
'posts_per_page'=> -1,
'tax_query' => array( array(
'taxonomy' => 'category',
'field' => 'term_id',
'terms' => $categories
) )
);
$string = '';
$query = new WP_Query( $args );
if( ! $query->have_posts() ) {
return false;
}
while( $query->have_posts() ){
$query->the_post();
$string .= '<div id="childWrapper"><div id="childImage">' . get_the_post_thumbnail() . '</div><div style="clear: both;"></div><div id="childName">' . get_the_title() . '</div><div style="clear: both;"></div></div>';
}
wp_reset_postdata();
return $string;
}