Knockout.js 查找电子邮件地址(如果已存在于 observablearray 中)

Question

我有 ViewModel，它的属性之一是 observableArray(接收器)。我想在添加新记录之前检查集合中是否已经存在电子邮件地址，以确保不会出现重复条目​​。请帮忙。我尝试了这里的方法 How to conditionally push an item in an observable array?但它不工作。它无法检测要添加的项目是否已在列表中。我希望如果调用 AddReceiver 函数，我将验证 newReceiverData 电子邮件地址。这是我的代码。

View 模型

var ReceiversViewModel = function () {
    var self = this;
    var errorModal = {};

    self.firstname = ko.observable();
    self.lastname = ko.observable();
    self.receivers = ko.observableArray();
    self.newReceiver = {
        receiverfirstname: ko.observable(''),
        receiverlastname: ko.observable(''),
        receiveremailaddress: ko.observable('')
    };
       self.AddReceiver = function () {
        var newReceiverData = ko.toJS(self.newReceiver);
        if (ReceiverValidate() == true) {
        //check if newReceiverData.receiveremailaddress value already exist
            self.receivers.push({
                EmailAddress: newReceiverData.receiveremailaddress,
                FirstName: newReceiverData.receiverfirstname,
                LastName: newReceiverData.receiverlastname
            });
        }
    }; 
};

Answer 1

我通常在轻量级 underscore.js 中使用“any”函数当我使用 knockout 时，库用于此类事情。

if (!_.any(self.receivers(), function(receiver) { return receiver.receiveremailaddress() == newReceiver.receiveremailaddress(); })) {
            // push new receiever 
        }

您可以根据需要使比较功能简单或复杂。