[Catalyst] Keep getting checksum mismatch problems each time I regenerate my schema files

[Tomas Doran]

This discussion should be on the DBIC list really, as it doesn't have  
much to do with Catalyst.

On 17 Apr 2009, at 03:27, kakimoto at tpg.com.au wrote:
> Quoting John Romkey <romkey at apocalypse.org>:
>> Look in the schema file. You see this line?
>>
>> # DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum: XXXXXXXX
>>
>> it means that you modified that line or something above it...
>
> Yes I do see the line.
>
> If the way the check is to be done is so stringent (ie. permissions on
> the files it touches or even new lines, surely, the makers of this
> package could come up with somethign better. I don't have the same  
> issue
> when using Ruby on Rails' Active Records).
>


What? There is nothing done with permissions, I have no idea what  
you're talking about with that.

And I can't think of a better way to ensure that someone hasn't  
altered the generated code than what is done. Conceptually you  
_could_ in some way get the optree of the code, rather than the text,  
and then checksum that (so that you could add new lines and spaces  
and comments to the generated code), but this is _extremely non- 
trivial_ to implement, and also still wouldn't provide a way to leave  
your modifications in place when the code was re-generated, so I  
don't see any benefit to investigating it.

Saying ActiveRecord doesn't do this isn't really helpful - you're not  
comparing like with like here.. ActiveRecord does around the same as  
'create=dynamic' for schema mode, so there really _is no generated  
code_, as its introspected each time.

You _can_ do your schema like this if you want to, but that opens a  
whole load of different issues I won't go into here (which  
ActiveRecord also suffers from).

Cheers
t0m