What's wrong with Config::ApacheFormat? You have the ability to have
arbitrarily-deep nested structures that you can call whatever you want
...
Rob
On Mon, 27 Dec 2004 16:04:40 -0500, Stevan Little
<[EMAIL PROTECTED]> wrote:
> So I have been using my module IOC a lot lately, so far so good, but I
> have found that writing the code to create all the containers and
> services and such gets quite tedious. For instance to do a basic DBI
> container, I do something like this:
>
> my $r = IOC::Registry->new('MyApp');
> my $c = IOC::Container->new('DBI');
> $c->register(IOC::Service::Literal->new('dsn' =>
> 'dbi:mysql:test'));
> $c->register(IOC::Service::Literal->new('username' => 'test'));
> $c->register(IOC::Service::Literal->new('password' => '****'));
> $c->register(IOC::Service::ConstructorInjection->new('connection' => (
> 'DBI', 'connect' [
> IOC::Service::ConstructorInjection->ComponentParameter('dsn'),
>
> IOC::Service::ConstructorInjection->ComponentParameter('username'),
>
> IOC::Service::ConstructorInjection->ComponentParameter('password')
> ]
> )));
> $r->registerContainer($c);
>
> # ... then in my app all I have to do is
>
> my $reg = IOC::Registry->instance();
> my $db_conn = $reg->locateService('/MyApp/DBI/connection');
>
> Writing the code to configure the services, containers and registry
> though, can get quite tiring. Fortunately, I really only need to do
> this once and then just use it, but ideally I would like it to be a
> little less taxing on the carpal tunnel.
>
> My first idea was to create subclasss of IOC::Container that would take
> a number of arguments and return a fully formed container. I wrote a
> basic IOC::Container::DBI which only needed to be passed a $dsn,
> $username and $password and it would create what I have above. But that
> idea only works for common things which you do all the time, not for
> custom stuff.
>
> Then it occurred to me that it would be even nicer to have some kind of
> very basic configuration syntax/mini-language which would do this. So i
> searched the Config:: namespace on CPAN and found nothing which seemed
> to fit the bill.
>
> So before I start really writing a custom parser and such I thought I
> would get the opinion of others. Here is an example of how the above
> configuration might look:
>
> MyApp: [
> DBI: [
> dsn: 'dbi:mysql:test'
> username: test
> password: '****'
> connection: [ DBI connect [ @dsn @username @password ] ]
> ]
> ]
>
> This would roughly translate into the following perl data structure,
> which I would then use to create the actual IOC objects:
>
> {
> 'MyApp' => {
> 'DBI' => {
> 'dsn' => 'dbi:mysql:test',
> 'username' => 'test',
> 'password' => '****',
> 'connection' => [ 'DBI', 'connect', [ 'dsn',
> 'username', 'password'
> ]]
> }
> }
> }
>
> So as you can see in some cases, blocks ([]) will become hashes, and in
> others they will become arrays. The way it knows is that if the first
> value is a string with a colon at the end (:) it is a hash, otherwise
> it is an array. The '@' prefix/sigil would indicate that the value is
> not just a string, but a path or name of a component within the
> IOC::Container.
>
> I have worked out more complex examples as well, for instance this is
> how IOC::Service::SetterInjection would be handled:
>
> FileLogger: [
> FlieLogger new [
> [ set_log_file: @/MyApp/log_file_name ]
> ]]
>
> this would become the following IOC configuration:
>
> IOC::Service::SetterInjection->new('FileLogger' => (
> 'FileLogger', 'new', [
> { set_log_file => '/MyApp/log_file_name' }
> ]
> )))
>
> I have also devised a way to do the regular IOC::Service object, which
> use the sub-ref parameter. Here is an example of the DBI configuration
> above using this:
>
> MyApp: [
> DBI: [
> dsn: 'dbi:mysql:test'
> username: test
> password: '****'
> connection: <<<
> my $c = shift;
> return DBI->connect($c->get('dsn'),
> $c->get('username'),
> $c->get('password'));
> >>>
> ]
> ]
>
> It would be like substituting this in the first config example:
>
> $c->register(IOC::Service::->new('connection' => sub {
> my $c = shift;
> return DBI->connect($c->get('dsn'), $c->get('username'),
> $c->get('password'));
> }));
>
> Obviously the string between '<<<' and '>>>' will get wrapped in 'sub {
> }' and evaled. I am assuming that this will work since '<<<' and '>>>'
> are not valid perl identifiers, so I can easily find the end of that
> string.
>
> As I said, I am still toying around with this. I have created a quick
> and dirty parser already so I know the syntax is workable for that
> angle. My question to you all, is;
>
> 1) Does this sound like a good idea?
> 2) Does this syntax look good?
> 3) Is there any existing Config:: module out there which will do the
> dirty work for me?
> 4) Anyone got any better ideas?
>
> Thanks,
>
> Steve
>
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>
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