Gutenberg: adding an "onChange" Event to specific block field

Question

I have an existing Block which was created with LazyBlocks.

I need to overwrite the title and the post image of the current WordPress post when the corresponding field in the specific block is changed. I googled quite a bit but didn't got a clue.

Example:

Thanks for your help!

Answer 1

Lazyblocks provide different js-filters. Following is fired if a value of the specific block has changed.

wp.hooks.addFilter( 'lzb.editor.control.updateValue', 'lazyblock/fmtest', function ( val, control, childIndex ) {
    console.log( val, control, childIndex );
    /*do your stuff*/
    return val;
} );