敲除-自定义绑定-将变量从init传递到update

可以通过设置辅助对象来实现这一点,这些辅助对象存储到元素中。

E、 g。

function SomeBindingHelper(element, valueAccessor, allBindings, viewModel, bindingContext) {
    var sharedVariable = "Banana";

    // Call on init.
    this.init = function () {
        console.log("init", sharedVariable);
    }

    // Call on update.
    this.update = function () {
        console.log("update", sharedVariable);
    }
}

ko.bindingHandlers.someBinding = {
    init: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
       var bindingHelper = new SomeBindingHelper(element, valueAccessor, allBindings, viewModel, bindingContext);
       bindingHelper.init();
       ko.utils.domData.set(element, "someBindingHelper", bindingHelper);
    },
    update: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
       var bindingHelper = ko.utils.domData.get(element, "someBindingHelper");
       bindingHelper.update();
    }
}