Delete block settings when removing a block from hook_block_info()

Question

My module creates blocks. These may come and go and I want to make sure I'm not leaving cruft behind, e.g. settings from the configure block screen for blocks that no longer exist (i.e. are no longer returned by my hook_block_info()).

I've noticed that removing a block and then adding a new one (with the same delta) magically brings up the old config.

What should I do in my module to clean out this config? (or is it somehow done for me in an occasional cron?)

Answer 1

I hope this should work if I get your question right.

db_delete('block')
  ->condition('module', MODULE)
  ->condition('delta', DELTA)
  ->execute();
db_delete('block_node_type')
  ->condition('module', MODULE)
  ->condition('delta', DELTA)
  ->execute();
db_delete('block_role')
  ->condition('module', MODULE)
  ->condition('delta', DELTA)
  ->execute();

cache_clear_all(MODULE_DELTA, 'cache_block');

Where MODULE resembles your module name and DELTA resembles your block's delta.

Answer 2

Block configuration might be saving through variable_set();

Run a query on your database, as

SELECT * FROM system WHERE name LIKE '%block%';

Replace %block% with your with probable block configuration form fields machine name, to check if there is a variable

Also in your custom module check the implementation side hook_block_save(), if any varibale_set(); is there.

In case this is the problem you can implement hook_uninstall inside which you can do variable_delete('name_of_vraible_to_delete');