Featured image dan attachment object di WordPress

wp-featured-image-attachment.md

WordPress Featured Image dan Attachment Object

Enable featured image di template WordPress dan memanfaatkan attachment object di dalam WordPress template

Untested - Kalau ada error tolong direvisi

Enable fitur Featured Image di Themes

Aktifkan melalui functions.php template, fitur featured image di dalam WordPress dikenal dengan post-thumbnails

<?php
/**
* Theme's functions file
*/

// Enable featured image
add_theme_support( 'post-thumbnails' ); 

Hook ke Featured Image di dalam WordPress loop

Post thumbnail dari sebuah post dapat diakses melalui template tag get_the_post_thumbnail dan kita bisa memanfaatkan data yang ada di dalam object attachment melalui get_post_thumbnail_id.

<?php
// tampilkan featured image ke dalam template tag
// terekspos ketika berada di dalam loop

if ( has_post_thumbnail() ) {
    the_post_thumbnail();
}

Sementara untuk mengambil value tanpa menampilkan - contoh implementasi untuk memberikan style tambahan.

<?php
// tampilkan featured image ke dalam template tag
// terekspos ketika berada di dalam loop
// Syntax get_the_post_thumbnail( int|WP_Post $post = null, string|array $size = 'post-thumbnail', string|array $attr = '' )

$post_id = get_the_ID();
if ( has_post_thumbnail() ) {
    echo get_the_post_thumbnail( $post_id, 'thumbnail', array( 'class' => 'alignleft' ) );
}

Mendapatkan id dari featured image dan akses ke Attachment object

Manfaatkan get_post_thumbnail_id

<?php
// ambil id dari featured image
// di dalam WordPress loop
$post_id = get_the_ID();
$post_thumbnail_id = get_post_thumbnail_id( $post_id ); 
// ambil metadata
// syntax wp_get_attachment_metadata( $attachment_id, $unfiltered );

$metadata = wp_get_attachment_metadata( $post_thumbnail_id , false );

$metadata merupakan array - contoh

// output
 Array
   (
       [width] => 2400
       [height] => 1559
       [file] => 2011/12/press_image.jpg
       [sizes] => Array
           (
               [thumbnail] => Array
                   (
                       [file] => press_image-150x150.jpg
                       [width] => 150
                       [height] => 150
                       [mime-type] => image/jpeg
                   )
               [medium] => Array
                   (
                       [file] => press_image-4-300x194.jpg
                       [width] => 300
                       [height] => 194
                       [mime-type] => image/jpeg
                   )
               [large] => Array
                   (
                       [file] => press_image-1024x665.jpg
                       [width] => 1024
                       [height] => 665
                       [mime-type] => image/jpeg
                   )
               [post-thumbnail] => Array
                   (
                       [file] => press_image-624x405.jpg
                       [width] => 624
                       [height] => 405
                       [mime-type] => image/jpeg
                   )
           )
       [image_meta] => Array
           (
               [aperture] => 5
               [credit] => 
               [camera] => Canon EOS-1Ds Mark III
               [caption] => 
               [created_timestamp] => 1323190643
               [copyright] => 
               [focal_length] => 35
               [iso] => 800
               [shutter_speed] => 0.016666666666667
               [title] => 
           )
   )