ReactiveCocoa：仅订阅新值

I've created an event subscriber in viewDidLoad, as follows:

我在viewDidLoad中创建了一个事件订阅者，如下所示：

[RACObserve(_authenticationView.passwordInput.textField, text) subscribeNext:^(NSString* text)
{
     //handle this
}];

This fires whenever the textField.text property changes (expected), however it also fires once when created, or for the intitial value, which is not what I want.

每当textField.text属性发生更改（预期）时都会触发，但是它在创建时也会触发一次，或者触发初始值，这不是我想要的。

Of course I could filter this out, but I only want to filter the first event out. How do I do this?

当然我可以过滤掉它，但我只想过滤掉第一个事件。我该怎么做呢？

Requirements:

要求：

• If the password has a new empty value, present a validation message (can't proceed password empty).
• 如果密码具有新的空值，则显示验证消息（无法将密码设置为空）。
• If the password has a new non-empty value, talk to remote client.
• 如果密码具有新的非空值，请与远程客户端通信。

. . so what's the cleanest way to do this?

。 。那么最干净的方法是什么？

1 个解决方案

#1

If you just want to skip the first value, just stick a -skip:1 in there:

如果您只想跳过第一个值，只需在其中粘贴-skip：1：

[[RACObserve(_authenticationView.passwordInput.textField, text) skip:1] subscribeNext:^(NSString* text)
{
     //handle this
}];