我对 Rx* 完全陌生。我正在尝试使用 RxJS 为我的论文创建 MVC 的反应式版本。它松散地基于https://github.com/staltz/mvi-example
在开始编写代码之前,我可能应该更多地研究 RxJS,但我意识到我通常通过跳到池的最深处来学习最好的东西。现在我完全被困住了。
视图有一个带有数值的文本字段和一个按钮。按下按钮会更改文本的颜色,单击文本会迭代数值。该值存储在模型中,因此“链”通过所有三个对象(视图->控制器->模型->视图)。按下按钮不需要模型,因此链是 View->Controller->View。
其他一切正常,但链的最后一部分(-> 查看)给我带来了麻烦。单击文本(在视图中)会将更改传播到控制器和模型,但视图不会通知模型中的更改。我不明白为什么,因为我理解这一切的方式都是以相同的方式实现的。
我在下面的代码示例中添加了注释,以指定不被调用的函数。
代码可在此处获得。请注意,就像我说的,代码是针对我的论文的,所以一些设计决策和应用程序本身可能看起来很奇怪。下面我还尝试包括我认为最相关的部分。我知道我应该提供一个完整的例子,但在这种情况下这是不可能的。
对象获取的“obs”参数是我用来存储可观察对象的内部数据结构。相关部分是
var OBSERVABLES = {
observe: function(source, observer, observer_name) {
this.request(source, function(s) {
console.log("\t[" + source + " is being observed by " + observer_name + " (" + s.constructor.name + " -> " + observer.constructor.name + ")]")
return s.subscribe(
function myOnNext(x) {
console.log("\t(" + source + ") " + s.constructor.name + " -> OnNext -> (" + observer_name + ") " + observer.constructor.name)
observer.onNext(x)
},
function myOnError(err) {
console.log(error)
})
})
},
查看.js
var modelAmount = new Rx.Subject()
var textClicks = new Rx.Subject()
var buttonClicks = new Rx.Subject()
var changeColors = new Rx.Subject()
function View(obs, div) {
console.log("View :: New View")
obs = obs
div = div
var self = this
obs.observe("clickAmount", modelAmount, "modelAmount")
obs.observe("changeColor", changeColors, "changeColors")
obs.add("textClicks", textClicks)
obs.add("buttonClicks", buttonClicks)
//Draw HTML elements
render(div);
}
...
function onClick() {
console.log("View :: onClick() emits 'textClicks'");
textClicks.onNext()
}
function onButtonClick() {
console.log("View :: onButtonClick() emits 'buttonClicks'");
buttonClicks.onNext()
}
//Listen to controllers instruction to change the color
// DOES NOT WORK
var changeNumberColor = changeColors.map(function(c) {
console.log("View :: Listened to 'changeColor'")
if (c === undefined) {
c = getColor()
}
CONTENT.css('color', c)
});
//Listen to model's instruction to change the value
// DOES NOT WORK
var setValue = modelAmount.last(function(latestValue) {
console.log("View :: Listened to 'clickAmount'")
console.log("View :: setValue(" + latestValue + ")")
CONTENT.text(latestValue)
});
控制器.js
var inputTextClicks = new Rx.Subject();
var inputButtonClicks = new Rx.Subject();
var obs = null;
function Controller(obs){
console.log("Controller :: New Controller")
obs = obs
obs.observe("textClicks", inputTextClicks, "inputTextClicks")
obs.observe("buttonClicks", inputButtonClicks, "inputButtonClicks")
obs.add("addAmount", addAmount);
obs.add("changeColor", changeColor);
}
//Listen to input events and give instructions to model
var addAmount = inputTextClicks.map(function(){
console.log("Controller :: addAmount() listened to 'textClicks' and emits 'addAmount'")
return 1;
});
//Listen to button presses and give instructions to the view
var changeColor = inputButtonClicks.map(function(){
console.log("Controller :: ChangeColor() listened to 'buttonClicks' and emits 'changeColor'")
return 1;
});
模型.js
var controllerAddAmount = new Rx.Subject();
var obs = null;
//Stores the texts value. Starts at 0
var VALUE = 0;
function Model(obs){
console.log("Model :: New Model")
obs = obs
obs.observe("addAmount", controllerAddAmount, "controllerAddAmount")
obs.add("clickAmount", amountChanged)
}
//Listen to the controller about changing the value, notify the view about the new value
var amountChanged = controllerAddAmount.map(function(val){
console.log("Model :: amountChanged() listened to 'addAmount' and emits 'clickAmount'")
VALUE += val
console.log("Model :: Amount Changed to " + VALUE)
return VALUE;
})
所以问题是 View.setValue() 和 View.setNumberColor()。