hook_block_info should document max length of delta/array key

Hmmmm....

The maximum length of the array key on the return value (the "delta") is 32 bytes, as you can see from block_schema():

      'delta' => array(
        'type' => 'varchar', 
        'length' => 32, 
        'not null' => TRUE, 
        'default' => '0', 
        'description' => 'Unique ID for block within a module.',
      ), 

I think that is what you are talking about, since you mention a value of 'pending_user_notification'. That would typically be a block delta, not a 'info' element. I agree this maximum should be documented, and it isn't currently.

I don't think there's really a maximum length for the 'info' element of the return value though -- that is the default human-readable title for the block, and it is not stored in the database as far as I can tell. I looked through _block_rehash(), which builds the block list for the block admin page, and I'm not seeing any usage of the 'info' component that would have a maximum length.

There is also a maximum length for the human-readable title that someone configures in the user interface, which is apparently 64 bytes:

     'title' => array(
        'type' => 'varchar', 
        'length' => 64, 
        'not null' => TRUE, 
        'default' => '', 
        'description' => 'Custom title for the block. (Empty string will use block default title, <none> will remove the title, text will cause block to use specified title.)', 
        'translatable' => TRUE,
      ), 

So I'm assuming you meant the array key and not the 'info' component? If not, what error are you getting?

Agreed, the 32 byte limit of delta needs to be documented. Good project for a novice doc contributor.

This patch adds "The maximum length for delta values is 32 characters." to the paragraph describing delta values.

The maximum length is 32 *bytes*, not 32 characters. Not the same thing in, for instance, Japanese.

Oops! This one changes 'characters' to 'bytes'.

Looks fine, thanks!

#8: 1025372.patch queued for re-testing.

Committed to CVS HEAD. Thanks.

See also #2182201: block_schema(): Change block.delta from varchar(32) to varchar(64)