javascript - 在拦截绑定(bind)行为期间，“this”不引用当前对象上下文

Question

在 Aurelia 应用程序中，我正在使用绑定(bind)行为。它看起来像这样:

<div id="slider" ej-slider="e-value.two-way:controller.item.progress & intercept:controller.saveChange;" ></div>

拦截绑定(bind)行为from here正在绑定(bind) controller.saveChange它确实被调用了。

但是，问题是在该方法中，this不是指 Controller ，而是指绑定(bind)。因此我无法访问进行实际保存所需的 Controller 的方法和属性。

这就是绑定(bind)行为的样子:

export class InterceptBindingBehavior {

readonly interceptMethods = ['updateTarget', 'updateSource', 'callSource'];

bind(binding, scope, interceptor) {
    let i = this.interceptMethods.length;
    while (i--) {
        let method = this.interceptMethods[i];
        if (!binding[method]) {
            continue;
        }
        binding[`intercepted-${method}`] = binding[method];
        let update = binding[method].bind(binding);
        binding[method] = interceptor.bind(binding, method, update);
    }
}

unbind(binding, scope) {
    let i = this.interceptMethods.length;
    while (i--) {
        let method = this.interceptMethods[i];
        if (!binding[method]) {
            continue;
        }
        binding[method] = binding[`intercepted-${method}`];
        binding[`intercepted-${method}`] = null;
    }
}
}

如何解决这个问题？

Answer 1

与我的评论相关，作为一个快速而肮脏的修复，我会尝试分别将类和方法作为参数传递。我测试了它，它确实有效。但也许一些 aurelia 专家知道如何处理这个问题的更好方法:

html

<div id="slider" ej-slider="e-value.two-way:controller.item.progress & intercept:controller:'saveChange'"></div>

InterceptBindingBehavior.ts

export class InterceptBindingBehavior {
readonly interceptMethods = ['updateTarget', 'updateSource', 'callSource'];

bind(binding, scope, interceptorClass, interceptorMethod) {
    let i = this.interceptMethods.length;
    while (i--) {
        let method = this.interceptMethods[i];
        if (!binding[method]) {
            continue;
        }
        binding[`intercepted-${method}`] = binding[method];
        let update = binding[method].bind(binding);
        binding[method] = interceptorClass[interceptorMethod].bind(interceptorClass, method, update);
    }
}

unbind(binding, scope) {
    let i = this.interceptMethods.length;
    while (i--) {
        let method = this.interceptMethods[i];
        if (!binding[method]) {
            continue;
        }
        binding[method] = binding[`intercepted-${method}`];
        binding[`intercepted-${method}`] = null;
    }
}