update_post_meta WordPress Block Editor (Gutenberg) Equivalent is editPost

If you are wondering how to update_post_meta on the current post with Gutenberg, this is the article for you. You can just use editPost like so:

wp.data.dispatch( 'core/editor' ).editPost( {
    meta: {
        wholesomecode_meta_key_example: 'Example',
    },
} );

The code above will update the post meta wholesomecode_meta_key_example with the value 'Example'.

Remember that you will need to register your meta key using the show_in_rest argument, like I showed you in the get_post_meta example.

Update the Meta from a different Post ID

If you want to update the post meta of a post by its ID, you can use editEntityRecord like in the following example:

wp.data.dispatch( 'core' ).editEntityRecord( 'postType', 'post', 42, {
    meta: {
        wholesomecode_meta_key_example: 'Example',
    },
} );

It works in pretty much the same way, but you have to pass in the post type and the ID.