在ReactiveCocoa中实现信号信号的"组合最新"的最佳方法是什么?我有以下问题:
给定 N 个文本字段,订阅 UIControlEditingEventChanged
事件,并根据调用的值创建新信号。每个订阅者订阅一次,然后这些值相互结合使用。这就是我得到的:
__block NSMutableSet *subscriptions = [NSMutableSet set];
RACSignal *validationSignals = [[[[TEXT_FIELDS rac_sequence].signal flattenMap:^RACStream* (UITextField *textField) {
return [textField rac_signalForControlEvents:UIControlEventEditingChanged];
}] flattenMap:^RACStream *(UITextField* textField) {
if(![subscriptions containsObject:textField]) {
[subscriptions addObject:textField];
return [textField rac_validationSignal];
}
return [RACSignal empty];
}]];
其中rac_validationSignal
是我自己的类处理UITextFields的验证。信号正确通过,但一次只能通过一个。我需要一次获得所有订阅的值,以便获得所有编辑字段的有效性。
编辑:
一种可能的解决方案涉及一个可变数组,我将新字段添加到该数组中,并像往常一样发送组合信号。这似乎很好,还有其他想法吗?
__block NSMutableSet *subscriptions = [NSMutableSet set];
__block NSMutableArray *signals = [NSMutableArray array];
RAC(self.editButton, enabled) =
[[[[TEXT_FIELDS rac_sequence].signal flattenMap:^RACStream* (UITextField *textField) {
return [textField rac_signalForControlEvents:UIControlEventEditingChanged];
}] flattenMap:^RACStream *(UITextField* textField) {
if(![subscriptions containsObject:textField]) {
[subscriptions addObject:textField];
[signals addObject:[textField rac_validationSignal]];
return [RACSignal combineLatest:signals];
}
return [RACSignal empty];
}] map:^NSNumber *(RACTuple *value) {
for(NSNumber *isValid in value) {
if(![isValid boolValue]) { return @(NO); }
}
return @(YES);
}];
谢谢!
你可以试试这个:
NSArray *TEXT_FIELDS = @[[txt1.rac_textSignal distinctUntilChanged],[txt2.rac_textSignal distinctUntilChanged]];
[[RACSignal combineLastest:TEXT_FIELDS reduce:^ (NSSTring *txt1, NSString *txt2) {
// Return your validate method here
// Signal only send `next` value it is different from previous `next` value
return [self inputvalication];
}] setKeyPath:@"enabled" onObject:self.myButton];