Gutenberg: How to update the block and add new attributes without crashing it?

[muhammedmagdi]

I had an issue with any block used already and saved in a page then I tried to update the block adding new attributes to it. when reloading this page, I found the block had crashed .. I know because the isValid function runs and checks the output after saving identical or not but that means that I can't update any block with any way. It should be more developer friendly. Is there any way to avoid this crash?

[tofumatt]

You'll need to provide a deprecated version of your block; there is documentation on that here: https://github.com/WordPress/gutenberg/blob/master/docs/block-api/deprecated-blocks.md

Have a look through existing blocks in the blocks library: https://github.com/WordPress/gutenberg/tree/master/packages/block-library/src to see real-world examples 😄