<code>
RACChannelTo(self, name) = RACChannelTo(self.model, name);
RACChannelTo(self, blurb) = RACChannelTo(self.model, blurb);
RACChannelTo(self, filmType, @(ASHRecipeFilmTypeColourNegative)) = RACChannelTo(self.model, filmType, @(ASHRecipeFilmTypeColourNegative));
</code>
這是一個(gè)雙向綁定，self.name和self.model.name任何一個(gè)改變，另外一個(gè)也會(huì)改變。第三個(gè)參數(shù)是默認(rèn)值，出現(xiàn)nil就用這個(gè)來(lái)代替。有了它，model和ViewModel就可以雙向同步。
<code>
RACChannelTerminal *channelA = RACChannelTo(self, valueA);
RACChannelTerminal *channelB = RACChannelTo(self, valueB);
[[channelA map:^id(NSString value) {
if ([value isEqualToString:@"西"]) {
return @"東";
}
return value;
}] subscribe:channelB];
[[channelB map:^id(NSString value) {
if ([value isEqualToString:@"左"]) {
return @"右";
}
return value;
}] subscribe:channelA];
[[RACObserve(self, valueA) filter:^BOOL(id value) {
return value ? YES : NO;
}] subscribeNext:^(NSString x) {
NSLog(@"你向%@", x);
}];
[[RACObserve(self, valueB) filter:^BOOL(id value) {
return value ? YES : NO;
}] subscribeNext:^(NSString x) {
NSLog(@"他向%@", x);
}];
self.valueA = @"西";
self.valueB = @"左";
</code>
