javascript - 链接 Knockout 自定义绑定(bind)

Question

我有一个 Knockout 自定义绑定(bind)处理程序，我想在其中调用 foreach 绑定(bind)功能，然后调用回调函数。当我尝试执行此操作时，我不断收到“ Uncaught Error :您不能将绑定(bind)多次应用于同一元素。”错误。

我的自定义绑定(bind)非常简单( typescript ):

/// <reference path="knockout.d.ts" />
ko.bindingHandlers["postForeach"] = {
    init: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        if (!allBindingsAccessor().postForeachCallback)
            throw "Callback not defined for postForeach binding!";

        //call foreach init functionality
        ko.bindingHandlers['foreach'].init(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext);
    },
    update: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
            //call foreach update functionality
            ko.bindingHandlers['foreach'].update(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext);
            //call callback
            allBindingsAccessor().postForeachCallback();
    }
};

在构建这个过程中我遗漏了什么吗？

谢谢!

编辑:

回调函数

self.populateMainContentWindow = function () {
                    var dataTable = $(this.tableId).dataTable();
        dataTable.fnDestroy();

                // create the datatable
                        var actualTable = this.jQuery(this.tableId);
        if (actualTable.length == 0) {
            return false;
        }

        // create the data table with options
        var newDataTable = actualTable.dataTable(this.options);

        // always set the width afterwards
        actualTable.css("width", "100%");
            };

数据绑定(bind)签名(在“with”绑定(bind)中):

postForeach: array, postForeachCallback: $parent.viewModel().populateMainContentWindow

Answer 1

Knockout 使用 init 的返回值来确定它是否应该处理元素的后代。您可以只返回 foreach.init 函数的值，也可以从您的 init 函数中专门返回 { controlsDescendantBindings: true }:

init: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
    if (!allBindingsAccessor().postForeachCallback)
        throw "Callback not defined for postForeach binding!";

    //call foreach init functionality
    return ko.bindingHandlers['foreach'].init(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext);
},

引用:http://knockoutjs.com/documentation/custom-bindings-controlling-descendant-bindings.html