Custom image sizes missing in the media up-loader in Wordpress administration

Does your Wordpress media uploader in the administration miss the custom images sizes that you have configured? Don't worry.

In Wordpress 3.5 something seemed to have changed and any custom image sizes weren't available to select when inserting an image to a post or page. I really don't know what have changed but I know the solution and it's quite simple.

The thing you need to do is to create an filter in your functions.php that modify the Wordpress built-in function "image_size_names_choose()" and add all your custom image size to the "list".

Add this following code to your functions.php-file:

function my_custom_sizes( $sizes ) {    return array_merge( $sizes, array(        'custom-300' => __('Custom 300')    ) );}add_filter( 'image_size_names_choose', 'my_custom_sizes' );

That's it!

And if your don't remember how to add a custom image size in Wordpress. It's simple. Add this code to your functions.php-file:

add_image_size( 'custom-300', 300, 300 );

Change or modify elements in the content in Wordpress

Have you ever wanted to change the output of a Wordpress page or a post? Maybe modify the H1-elements in the content or something else. The solution is quite simple to achieve this.

Lets say we wanted to add something, in this case a header-element before the H1-element and a closing one right after. This is how you do it:

Put this code below in your functions.php-file:

function filter_h1_pages( $content ) {
$content = str_ireplace( '<h1>', '<header><h1>', $content ); return str_ireplace( '</h1>', '</header></h1>', $content );}add_filter( 'the_content', 'filter_h1_pages' );

What the code does is replacing a string with something else, twice and then return it. So we have filtered the main function the_content in Wordpress.