BlockExample::formValidate in modules/examples/block_example/block_example.inc

Validates the form settings.

BlockText::formValidate in core/modules/layout/includes/block.text.inc

Validates the form settings.

NodeBlock::formValidate in core/modules/node/node.block.inc

Validates the form settings.

ViewsBlock::formValidate in core/modules/views/includes/views.block.inc

Validate handler to validate the form settings.