Allow developers to use a generic reindex callback

As written, this is going to break backward compatibility for all the existing reindex callback functions, which expect the second parameter to be an optional bundle parameter and not the entity type.

In apachesolr alone, to get this to work correctly, you'd need to change apachesolr_index_node_solr_reindex to take the newly added second parameter. But this also means that all of contrib would need to change, which seems quite wasteful.

That patch would be a lot less disruptive if the new argument is added at the end of the function.

I've done the suggested changes and reapplied the patch against the latest 7.x-1.x branch and tested it with nodes and custom entities.

I think that this is still going to cause problems with backwards compatibility. If someone already has a custom reindex function without the additional argument passed, and this were to call that function, PHP will complain about the additional argument. Please contact one of the module maintainers and work out the architecture for this. One suggestion I have is to add a new argument called 'reindex callback version' and check that, and only pass the additional argument if this is set to the new version.

As this is currently written, the additional argument needs to be added to the apachesolr_index_node_solr_reindex doxygen.

@douggreen,

I just realized that PHP doesn't actually sends errors or notices when a function receives additional parameter. Instead, it allows it so that we can define function with a variable number of arguments.

So if a custom module is expecting only two parameters and we send 3, it won't make a difference, since we didn't change the order of the parameters.

interesting, agree. I tested the argument error/warning locally. RTBC from me too.