Reply To: oEmbed Cache

• Chauncey McAskill

• August 22, 2018 at 6:05 am

Unfortunately, a call is made each time.

Looking at acf_field_oembed::wp_oembed_get(), the field type relies primarily on WordPress’ wp_oembed_get(). That function does not support caching.

If wp_oembed_get() fails, then the field type will try with WP_Embed::shortcode() which does support caching (internally uses wp_oembed_get() :p ).

I’ve come up with two solutions.

1. Skip format value

$url   = get_field('oembed', false, false);
$embed = $wp_embed->shortcode([ 'width' => 640, 'height' => 390 ], $url);

2. Via ACF Filters

The solution I implemented:

/** Disables acf_field_oembed::format_value() */
add_action( 'acf/init', function () {
    $field_type = acf_get_field_type('oembed');
    remove_filter( 'acf/format_value/type=oembed', [ $field_type, 'format_value' ] );
}, 1 );

/** Fetch the cached oEmbed HTML; Replaces the original method */
add_filter( 'acf/format_value/type=oembed', function ( $value, $post_id, $field ) {
    if ( ! empty( $value ) ) {
        $value = acf_oembed_get( $value, $post_id, $field );
    }

    return $value;
}, 10, 3 );

/** Cache the oEmbed HTML */
add_filter( 'acf/update_value/type=oembed', function ( $value, $post_id, $field ) {
    if ( ! empty( $value ) ) {
        // Warm the cache
        acf_oembed_get( $value, $post_id, $field );
    }

    return $value;
}, 10, 3 );

/**
 * Attempts to fetch the embed HTML for a provided URL using oEmbed.
 *
 * Checks for a cached result (stored as custom post or in the post meta).
 *
 * @see  \WP_Embed::shortcode()
 *
 * @param  mixed   $value   The URL to cache.
 * @param  integer $post_id The post ID to save against.
 * @param  array   $field   The field structure.
 * @return string|null The embed HTML on success, otherwise the original URL.
 */
function acf_oembed_get( $value, $post_id, $field )
{
    if ( empty( $value ) ) {
        return $value;
    }

    global $wp_embed;

    $attr = [
        'width'  => $field['width'],
        'height' => $field['height'],
    ];

    remove_filter('embed_oembed_html', 'Roots\\Soil\\CleanUp\\embed_wrap');

    $html = $wp_embed->shortcode($attr, $value);

    add_filter('embed_oembed_html', 'Roots\\Soil\\CleanUp\\embed_wrap');

    if ( $html ) {
        return $html;
    }

    return $value;
}