should I check the existance of weakself before @strongify(self) ?

[yhvh009]

As the other practice in weak and strong, it recommends that we should check whether the weakself is null before we strongify it. It looks like this:

__weak weakself = self
someblock {
  if (weakself) {
    __strong self = weakself
    [self doSomeAction];
...
  }
}

I know rac does a lot of work ahead, but I want to make is it necessary that we should check it or not. And if not, how does the @strongify(self) do this. Thanks.

[ikesyo]

Looks like you are referring to the 2.x ReactiveCocoa Objective-C API. I transfer this to https://github.com/ReactiveCocoa/ReactiveObjC.

[n8gray]

Generally you want to do the opposite, since weakself can theoretically become null between the time you check and the time you strongify it.

__weak weakself = self
someblock {
  __strong self = weakself
  if (self) {
    [self doSomeAction];
...
  }
}

[greenzeal]

Generally you want to do the opposite, since weakself can theoretically become null between the time you check and the time you strongify it.

__weak weakself = self
someblock {
  __strong self = weakself
  if (self) {
    [self doSomeAction];
...
  }
}

old conversation here:) but why we would need to check self for nil in that case? if calling on nil method will do nothing anyway.