Save disk space and creates custom images sizes only where is required.
Custom filters to allow easy update of images sizes for Wordpress.
Picture from WikiImages
This is not a plugin, you can just download the class-katana.php
or use composer to add it as a dependency in your website or plugin.
After you download the file make sure to include the file using include function.
In order to have access to the filters you need to create a new instance of the Kata object.
$katana = new Katana();Also makes sure to inclode the file class-katana.php into your
functions.php file or in your plugin directory. After that you
can add all your custom filters that you may require.
This library comes with custom filters that allows edit what sizes are
generated under some custom post types or under a specific post_id.
Note: The default size of the image is always generated no matter if you remove all sizes.
Each filter allow to return what sizes of images are needed for that
particular filter, the returned sizes represents the allowed images
sizes, each size is the name that was registered when you created an
image size using add_image_size.
{post_type}, can be any post type declared on the site, post page or
even a custom one, like movies.
This filter allows to refine the sizes of images for a certain post type.
Example
This example remove all the sizes from all of the pages, so any time you add an image on a page it wont create any new size of image.
add_filter('katana_refine_page', 'remove_all_sizes_from_pages');
function remove_all_sizes_from_pages( $sizes ){
// Clear all the sizes of images
$sizes = array();
return $sizes;
}{post_id}, is the id of the post, page or custom post type all new
entries has a post_id
This filter allow you to change the required sizes on a particular post_id all posts, pages or custom post types has a post_id than can be used for this.
Example
Imagine we have previously declared an author_profile_image size of
image, like:
add_image_size( 'author_profile_image', 350, 350, true );We need to creates images of the author_profile_image size only in the
entry with the id: 105.
add_filter('katana_refine_105', 'allow_only_author_profile_image');
function allow_only_author_profile_image( $sizes ){
$sizes = array( 'author_profile_image' );
return $sizes;
}{template_slug}, is the slug of the template, the slug is where is
located the template, replacing - and / by _ and witout the .php
extension.
Examples
| Location | Filter name |
|---|---|
| page-templates/full.php | page_templates_full |
| page-templates/shop.php | page_templates_shop |
| portfolio.php | portfolio |
Example
This filter just allow to create two sizes of images in the
page-template/full.php:
- poster
- landscape
add_filter('katana_refine_page_templates_full', 'image_sizes_for_full_page_template');
function image_sizes_for_full_page_template( $sizes ){
$sizes = array( 'poster', 'landscape' );
return $sizes;
}