在订阅相同的 observable 时获取 observable 的先前值 [英] Get previous value of an observable in subscribe of same observable

问题描述

在收到新值之前，是否有可能在淘汰赛中获得对该 observable 的订阅中的 observable 的当前值?

Is it possible in knockout to get the current value of an observable within a subscription to that observable, before it receives the new value?

示例:

this.myObservable = ko.observable();
this.myObservable.subscribe(function(newValue){
    //I'd like to get the previous value of 'myObservable' here before it's set to newValue
});

推荐答案

有一种方法可以像这样订阅 before 值:

There is a way to do a subscription to the before value like this:

this.myObservable = ko.observable();
this.myObservable.subscribe(function(previousValue){
    //I'd like to get the previous value of 'myObservable' here before it's set to newValue
}, this, "beforeChange");

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