Knockout.js 选择模板切换,选择不工作-模型未定义
使用修改后的版本,我计划有一个类似的分步向导 在PaymentModel视图模型步骤中,它有两个子视图模型(payment1Model和payment2Model),显示的子视图模型将取决于所选PaymentOption(选项1或选项2) 我使用PaymentModel上的以下代码在所选视图模型之间切换Knockout.js 选择模板切换,选择不工作-模型未定义,knockout.js,knockout-validation,Knockout.js,Knockout Validation,使用修改后的版本,我计划有一个类似的分步向导 在PaymentModel视图模型步骤中,它有两个子视图模型(payment1Model和payment2Model),显示的子视图模型将取决于所选PaymentOption(选项1或选项2) 我使用PaymentModel上的以下代码在所选视图模型之间切换 self.selectedPaymentOption.subscribe(function(newValue) { if(typeof newValue == "undefined")
self.selectedPaymentOption.subscribe(function(newValue) {
if(typeof newValue == "undefined")
return;
var found = ko.utils.arrayFirst(self.options(), function (item) {
return item.name() == newValue;
}, this);
self.selectedTemplate(found.template);
self.selectedModel(found.model());
},self);
我可以第一次在模板之间切换OK,但是当切换回来时,我得到一个空引用错误,下面的绑定失败
我怀疑这与在selectedModel
之前设置selectedTemplate
有关(反之亦然),并且一个试图绑定另一个(鸡和蛋的情况),因为模板使用
是否有任何方法可以推迟更新,直到选择Template和selectedModel都已更新,或者有更好的方法解决此问题
和下面的代码:
<div data-bind="template: { name: 'currentTmpl', data: currentStep }"></div>
<button data-bind="click: goPrevious, visible: canGoPrevious">Previous</button>
<button data-bind="click: goNext, visible: canGoNext, enable: modelIsValid">Next</button>
<script id="payment1Tmpl" type="text/html">
<p>payment option 1</p>
<input id="details1" type="text" data-bind="value: details1, valueUpdate: 'afterkeydown'" />
<select id="expiresMonth" data-bind="options: expiresMonthOptions, value: expiresMonth" />
<select id="expiresYear" data-bind="options: expiresYearOptions, value: expiresYear" />
</script>
<script id="payment2Tmpl" type="text/html">
<p>payment option 2</p>
<input id="details2" type="text" data-bind="value: details2, valueUpdate: 'afterkeydown'" />
</script>
<script id="currentTmpl" type="text/html">
<h2 data-bind="text: name"></h2>
<div data-bind="template: { name: getTemplate, data: model }"></div>
</script>
<script id="nameTmpl" type="text/html">
<fieldset>
<legend>Name</legend>
<p>
<label for"FirstName">First Name</label>
<input id="FirstName" type="text" data-bind="value: firstName, valueUpdate: 'afterkeydown'" />
<p data-bind="validationMessage: firstName"></p>
</p>
</fieldset>
</script>
<script id="paymentTmpl" type="text/html">
<fieldset>
<p>
<label for"someOtherDetail">Some other detail</label>
<input id="someOtherDetail" type="text" data-bind="value: someOtherDetail, valueUpdate: 'afterkeydown'" />
</p>
<p>
<select data-bind="options: paymentOptions, value: selectedPaymentOption"></select>
<div data-bind="template: { name: selectedTemplate, data: selectedModel }"></div>
</p>
</fieldset>
</script>
<script id="confirmTmpl" type="text/html">
<fieldset>
<legend>Name</legend>
<b><span data-bind="text:NameModel.firstName"></span></b>
<br/>
</fieldset>
<button data-bind="click: confirm">Confirm</button>
</script>
ko.validation.configure({
insertMessages: false,
decorateElement: true,
errorElementClass: 'error'
});
function TemplatePage(id, name, template, model) {
var self = this;
self.id = id;
self.name = ko.observable(name);
self.template = template;
self.model = ko.observable(model);
self.getTemplate = function () {
return self.template;
};
}
function ViewModel() {
var self = this;
self.nameModel = ko.observable(new NameModel());
self.paymentModel = ko.observable(new PaymentModel());
var confirmModel = {
NameModel: self.nameModel(),
PaymentModel: self.paymentModel()
};
self.stepModels = ko.observableArray([
new TemplatePage(1, "Step1", "nameTmpl", self.nameModel()),
new TemplatePage(2, "Step2", "paymentTmpl", self.paymentModel()),
new TemplatePage(3, "Confirmation", "confirmTmpl", confirmModel)
]);
self.currentStep = ko.observable(self.stepModels()[0]);
self.currentIndex = ko.computed(function () {
return self.stepModels.indexOf(self.currentStep());
});
self.getTemplate = function (data) {
return self.currentStep().template();
};
self.canGoNext = ko.computed(function () {
return (self.currentIndex() < (self.stepModels().length - 1));
});
self.modelIsValid = ko.computed(function () {
if (typeof(self.currentStep().model().isValid) != "undefined") {
return self.currentStep().model().isValid();
}
else
return true;
});
self.goNext = function () {
if (self.currentIndex() < self.stepModels().length - 1) {
var count = self.currentIndex() + 1;
console.log(count);
self.currentStep(self.stepModels()[count]);
}
};
self.canGoPrevious = ko.computed(function () {
return self.currentIndex() > 0;
});
self.goPrevious = function () {
if (self.currentIndex() > 0) {
var count = self.currentIndex() - 1;
console.log(count);
self.currentStep(self.stepModels()[count]);
}
};
}
Payment1Model = function() {
var self = this;
self.details1 = ko.observable().extend({
required: true
});
self.expiresMonthOptions = ["01", "02", "03", "04", "05", "06", "07", "08", "09", "10", "11", "12"];
self.expiresYearOptions = ["2013", "2014", "2015", "2016"];
self.expiresMonth = ko.observable().extend({
required: true
});
self.expiresYear = ko.observable().extend({
required: true
});
ko.validation.group(self);
}
Payment2Model = function() {
var self = this;
self.details2 = ko.observable().extend({
required: true
});
ko.validation.group(self);
}
NameModel = function(model) {
var self = this;
//Observables
self.firstName = ko.observable().extend({
required: true
});
ko.validation.group(self);
return self;
};
var PaymentModel=function() {
var self = this;
self.payment1Model = ko.observable(new Payment1Model());
self.payment2Model = ko.observable(new Payment2Model());
self.someOtherDetail = ko.observable().extend({
required: true
});
self.options = ko.observableArray([
new TemplatePage(1, "Payment1", "payment1Tmpl", self.payment1Model()),
new TemplatePage(1, "Payment2", "payment2Tmpl", self.payment2Model()),
]);
var optionNames = [];
for(var i=0; i<self.options().length; i++)
{
optionNames.push(self.options()[i].name);
}
self.paymentOptions = optionNames;
self.selectedPaymentOption = ko.observable(optionNames[0]);
self.selectedTemplate = ko.observable();
self.selectedModel = ko.observable();
self.selectedPaymentOption.subscribe(function(newValue) {
if(typeof newValue == "undefined")
return;
var found = ko.utils.arrayFirst(self.options(), function (item) {
return item.name() == newValue;
}, this);
self.selectedTemplate(found.template);
self.selectedModel(found.model());
},self);
ko.validation.group(self);
self.isParentAndChildValid = function () {
if (typeof self.selectedModel() == "undefined")
return false;
return self.isValid() && self.selectedModel().isValid();
};
return {
someOtherDetail: self.someOtherDetail,
selectedPaymentOption: self.selectedPaymentOption,
paymentOptions: self.paymentOptions,
selectedTemplate: self.selectedTemplate,
selectedModel: self.selectedModel,
isValid: self.isParentAndChildValid
}
}
ko.applyBindings(new ViewModel());
以前的
下一个
付款选择1
付款选择2
名称
名字
其他一些细节
名称
证实
ko.validation.configure({
insertMessages:false,
装饰元素:是的,
errorElementClass:'错误'
});
函数模板页面(id、名称、模板、模型){
var self=这个;
self.id=id;
self.name=ko.observable(名称);
self.template=模板;
self.model=ko.可观察(model);
self.getTemplate=函数(){
返回self.template;
};
}
函数ViewModel(){
var self=这个;
self.nameModel=ko.observable(新nameModel());
self.paymentModel=ko.observable(新paymentModel());
var确认模型={
NameModel:self.NameModel(),
PaymentModel:self.PaymentModel()
};
self.stepModels=ko.array([
新模板页(1,“Step1”,“nameTmpl”,self.nameModel()),
新模板页(2,“Step2”,“paymentTmpl”,self.paymentModel()),
新模板页(3,“确认”,“确认TMPL”,确认模型)
]);
self.currentStep=ko.observable(self.stepModels()[0]);
self.currentIndex=ko.computed(函数(){
返回self.stepModels.indexOf(self.currentStep());
});
self.getTemplate=函数(数据){
返回self.currentStep().template();
};
self.canGoNext=ko.computed(函数(){
返回(self.currentIndex()<(self.stepModels().length-1));
});
self.modelIsValid=ko.computed(函数(){
if(typeof(self.currentStep().model().isValid)!=“undefined”){
返回self.currentStep().model().isValid();
}
其他的
返回true;
});
self.goNext=函数(){
if(self.currentIndex()0;
});
self.goPrevious=函数(){
if(self.currentIndex()>0){
var count=self.currentIndex()-1;
控制台日志(计数);
self.currentStep(self.stepModels()[count]);
}
};
}
Payment1Model=函数(){
var self=这个;
self.details1=ko.observable().extend({
必填项:true
});
self.expiresMonthOptions=[“01”、“02”、“03”、“04”、“05”、“06”、“07”、“08”、“09”、“10”、“11”、“12”];
self.expiresYearOptions=[“2013”、“2014”、“2015”、“2016”];
self.expiresMonth=ko.observable().extend({
必填项:true
});
self.expiresYear=ko.observable().extend({
必填项:true
});
验证组(自我);
}
Payment2Model=函数(){
var self=这个;
self.details2=ko.observable().extend({
必填项:true
});
验证组(自我);
}
名称模型=函数(模型){
var self=这个;
//可观测
self.firstName=ko.observable().extend({
必填项:true
});
验证组(自我);
回归自我;
};
var PaymentModel=函数(){
var self=这个;
self.payment1Model=ko.observable(新payment1Model());
self.payment2Model=ko.observable(新payment2Model());
self.someOtherDetail=ko.observable().extend({
必填项:true
});
self.options=ko.array([
新模板页(1,“Payment1”,“Payment1Templ”,self.payment1Model()),
新模板页(1,“Payment2”,“Payment2Templ”,self.payment2Model()),
]);
var optionNames=[];
对于(var i=0;i工作解决方案。现在它可以正常工作,没有任何错误。
您需要做的是停止使用分隔变量旁边的值:
self.selectedTemplate = ko.observable();
self.selectedModel = ko.observable();
而是使用另一个变量来保存选项数组中的选定选项:
self.selectedTemplate = ko.observable(self.options()[0]);
每次更改付款选择时,都会在选项数组中找到所选选项。只需将其放入新变量self.selectedTemplate:
var found = ko.utils.arrayFirst(self.options(), function (item) {
return item.name() == newValue;
}, this);
self.selectedTemplate(found);
相应地更改HTML:
<div data-bind="template: { name: selectedTemplate().template, data: selectedTemplate().model() }"></div>
(编辑)使用新的selectedTemplate()模板和selectedTemplate()模型()更改selectedTemplate和selectedModel的所有实例非常感谢+1并准备奖励,只是一个简单的问题-为什么当我将付款方式从选择更改为单选按钮时,初始视图中是否未选择第一个选项,有什么想法吗?我已在此处更新了小提琴,您所做的是设置对自我的引用。选项()[I].name属性。相反,您需要断开它们的连接,并将self.selectedPaymentOption的第一个值设置为op