Are Lazy properties needed?

[alexgarbarev]

I have problems with supporting it when reworking circular dependencies code.

[jasperblues]

Lots of folks have reported using them. But it would probably be fair enough to not support them in combination with lazy.

[alexgarbarev]

I changed internal API for property and parameter injections, now both used via method:

- (void)valueToInjectWithContext:(TyphoonInjectionContext *)context completion:(TyphoonInjectionValueBlock)result;

I had problem with creation lazyValues, used in TyphoonAssistedFactoryBase, because new API assume that value returned asyncronically (after resovling circular dependencies).

Finally I got:

- (void)doPropertyInjectionIfNeededOn:(id <TyphoonIntrospectiveNSObject, TyphoonPropertyInjectionInternalDelegate>)instance property:(id <TyphoonPropertyInjection>)property
                                 args:(TyphoonRuntimeArguments *)args
{
    if ([instance respondsToSelector:@selector(shouldInjectProperty:withType:lazyValue:)]) {
        TyphoonTypeDescriptor *propertyType = [instance typhoon_typeForPropertyWithName:property.propertyName];

        TyphoonPropertyInjectionLazyValue lazyValue = ^id {
            TyphoonInjectionContext *context = [[TyphoonInjectionContext alloc] init];
            context.destinationType = propertyType;
            context.factory = self;
            context.args = args;
            context.raiseExceptionIfCircular = YES;
            __block id result = nil;
            [property valueToInjectWithContext:context completion:^(id value) {
                result = value;
            }];
            return result;
        };

        if ([instance shouldInjectProperty:property withType:propertyType lazyValue:lazyValue]) {
            [self doPropertyInjection:instance property:property args:args];
        }
    } else {
        [self doPropertyInjection:instance property:property args:args];
    }
}

So, if lazyValue has circular dependency, exceptions will be raised. Is it ok?
@drodriguez can you verify new code? Is old code works fine with circular dependency?

[drodriguez]

I didn’t understand at first what “lazy” properties you meant. I will try to have a look at them later. But I don’t think I implemented them with circular dependencies in mind.

[alexgarbarev]

I think you used it when user fills TyphoonAssistedFactoryBase with property injections - to not resolve properties which user not used in future

[jasperblues]

'lazy simply meant 'Don't instantiate signletons until they're asked for'
. . we can expand the meaning is long as its compatible with the original
meaning.

On Tue, Mar 25, 2014 at 4:00 AM, Aleksey Garbarev
[email protected]:

I think you used it when user fills TyphoonAssistedFactoryBase with
property injections - to not resolve properties which user not used in
future

Reply to this email directly or view it on GitHubhttps://github.com//issues/203#issuecomment-38551558
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