Destroy hook

AI-generated Key Takeaways

• The destroy hook is called when a block is deleted from the workspace.

• It can be used to clean up data models or external resources.

• The destroy hook can be defined using a mixin in JSON or directly in the block's JavaScript definition.

• The destroy method runs after the block's parent is disposed but before children or fields are.

Blocks have a destroy hook, which is called when they are deleted from the workspace. This can be used to destroy any backing data models or external resources associated with the block that are no longer needed.

JSON

{
  // ...,
  "extensions":["destroy"],
}

Blockly.Extensions.registerMixin('destroy', {
  destroy: function() {
    this.myResource.dispose();
  }
});

In JSON, define a destroy hook with a mixin.

JavaScript

Blockly.Blocks['block_type'] = {
  destroy: function() {
    this.myResource.dispose();
  }
}

The destroy method is called after the block's parent has been disposed, but before any of its children or fields have been disposed.