Get images by a slug in Wordpress - php

Question

I am fairly new to Wordpress and I am trying to make a function that loads images under a media category. The media category has a slug that I want to pass into the function. If there is an easier way to do this please let me know. Below is my code so far:
Functions.php
function get_image_by_slug($slug) {
$query_images_args = array(
'post_type' => 'attachment',
'post_mime_type' =>'image',
'post_status' => 'inherit',
'posts_per_page' => -1,
'tax_query' => array(
array(
'taxonomy' => 'attachment_category',
'field' => 'slug',
'terms' => $slug,
),
),
);
$query_images = new WP_Query( $query_images_args );
$images = array();
foreach ( $query_images->posts as $image) {
$images[]= $image->guid;
}
return $images;
}
function display_image_by_slug() {
$imgs = get_image_by_slug($slug);
$html = '<ul class="list-inline">';
foreach($imgs as $img) {
$html .= '<li><img src="' . $img . '" alt="" /></li>';
}
$html .= '</ul>';
return $html;
}
add_filter('display_slugs','display_image_by_slug');
In page
<?php apply_filter('display slugs', 'test_slug');?>

Answer 1

An attachment of image or file is just a post with the post_status = inherit and the post_type = attachment and it is saved into the wp_post & wp_postmeta , so can be queried with WP_Query or get_posts.
Note: The slug (post_name) is unique per post type.
You have to pass your slug in the query by replacing YOUR-SLUG in this place. &name=YOUR-SLUG
$_head = get_posts('post_type=attachment&name=YOUR-SLUG&posts_per_page=1&post_status=inherit');
$header = $_head ? array_pop($_head) : null;
$header_url = $header ? wp_get_attachment_url($header->ID) : '';
Another Method you can build your own custom function with the help that i have provided below.
function get_attachment_url_by_slug( $slug ) {
$args = array(
'post_type' => 'attachment',
'name' => sanitize_title($slug),
'posts_per_page' => 1,
'post_status' => 'inherit',
);
$_head = get_posts( $args );
$header = $_head ? array_pop($_head) : null;
return $header ? wp_get_attachment_url($header->ID) : '';
and then you can call using this function.
$header_url = get_attachment_url_by_slug('YOUR-SLUG');

Answer 2

So after looking around the Wordpress docs and understanding Naresh's answer I was able to come up with my own answer. Here it is...
$id = 'YOUR SLUG';
$args = array(
'post_type' => 'attachment',
'post_status' => 'any',
'posts_per_page' => -1,
'tax_query' => array(
array(
'taxonomy' => 'media_category', // your taxonomy
'field' => 'slug',
'terms' => $id // term id (id of the media category)
)
)
);
$the_query = new WP_Query( $args );
if ( $the_query->have_posts() ) {
while ( $the_query->have_posts() ) {
$the_query->the_post();
echo '<li>'. wp_get_attachment_image( get_the_ID() );
if(empty_content(get_the_content())){
echo '<p>' . get_the_excerpt() . '</p></li>';
} else {
echo '<p>'.get_the_excerpt().'</p></li>';
}
}
} else {
// no attachments found
}
wp_reset_postdata();