Hooks

November 28, 2025 · View on GitHub

Filters

Filters

timmy/sizes

Filters the image sizes used in Timmy. Read more about this in Image Configuration.

Parameters

$sizes
(array) Image configuration array. Default array().

timmy/resize/ignore

Filters whether we should resize an image size.

When true is returned in this filter, the function will bailout early and the image will not be processed further.

Parameters

$ignore
(bool) Whether to ignore an image size. Default false.
$attachment
(string) The attachment post.
$size
(string|array) The requested image size as a string or array.
$file_src
(string) The file src URL.

Example

The following filter is already included in Timmy by default.

add_filter( 'timmy/resize/ignore', function( $return, $attachment ) {
    // Ignore GIF images
    if ( 'image/gif' === $attachment->post_mime_type ) {
    	return true;
    }
    
    return $return;
}, 10, 2 );

timmy/resize/src_image_size

Filters the image size that is used to generate image sizes.

Parameters

$size
(string) Image size to use for resizing. Can be full or original. In case of full, a scaled image size will be used if scaled images are active. Default original.
$attachment_id
(int) The attachment ID.

Example

// Don’t generate image sizes from full size images, but from scaled images.
add_filter('timmy/resize/src_image_size', function () {
    return 'full';
});

timmy/show_in_rest

Filters whether an image should be shown in the REST API.

This filter only runs then a REST request to an attachment is actually made, so any logic you apply here will only be applied for REST requests to wp/v2/media or endpoints that use media embeds.

Parameters

$show_in_rest
(bool) Whether to show the image in the REST API. Default true.
$attachment_id
(int The attachment ID.
$img_size
(array) Configuration values for the image size.

Example 1

// Don’t show any image size in REST API calls.
add_filter('timmy/show_in_rest', '__return_false');

Example 2

// Set `show_in_rest` based on the value in `show_in_ui`.
add_filter('timmy/show_in_rest', static function($show_in_rest, $attachment_id, $img_size) {
    $show_in_rest = $img_size['show_in_ui'] ?? false;

    return $show_in_rest;
}, 10, 3);

timmy/generate_srcset_sizes

Filters whether srcset sizes should be generated when an image is uploaded.

Parameters

$generate_srcset_sizes
(bool) Whether to generate srcset sizes. Passing false will prevent srcset sizes to generated when an image is uploaded. Default false.
$key
(string) The image size key.
$img_size
(array) The image size configuration array.
$attachment
(WP_Post) The attachment post.

Example

// Generate srcset sizes for all image sizes
add_filter( 'timmy/generate_srcset_sizes', '__return_true' );

timmy/upscale

Filters the default upscale parameters used for an image.

An upscale parameter set for an individual image size will always overwrite values set through this filter.

Parameters

$upscale_defaults
(array|bool) Default upscale parameters. Can be a boolean to set all values in the array or an associative array with keys allow and style_attr. Default array( 'allow' => false, 'style_attr' => true ).

Example

add_filter( 'timmy/upscale', function( $upscale ) {
    // Never set the style_attr for an image
    $upscale['style_attr'] = false;

    return $upscale;
} );

// Shortcut to set all upscale parameters to false
add_filter( 'timmy/upscale', '__return_false' );

Filters whether a default src attribute should be added as a fallback. If this filter returns true (the default), then a base64 string will be used as a fallback to prevent double downloading images in older browsers. If this filter returns false, then no src attribute will be added to the image. Use the timmy/src_default filter to define what should be used as the src attribute’s value.

Parameters

$use_src_default
(bool) Whether to apply the fallback. Default true.

Example

// Disable default src attribute.
add_filter( 'timmy/use_src_default', '__return_false' );

timmy/src_default

Filters the src default.

Parameters

$src_default
(string) Src default. Default data:image/gif;base64,R0lGODlhAQABAAAAADs=.
$image
(Timmy\Image) Timmy image instance.

Example

// Use the default src URL as a fallback.
add_filter( 'timmy/src_default', function( $src_default, $image ) {
    return $attributes['default_src'];
}, 10, 2 );

timmy/allowed_file_extensions

Filters the allowed file extensions to be processed with Timmy.

Parameters

$allowed_file_extensions
(array) Allowed file extensions. Default [ 'jpg', 'jpeg', 'jpe', 'png' ].

Example

// Add support for AVIF and WebP files.
add_filter( 'timmy/allowed_file_extensions', function( $allowed_file_extensions ) {
    $allowed_file_extensions[] = 'avif';
    $allowed_file_extensions[] = 'webp';
    
    return $allowed_file_extensions;
} );