由于某些原因,foreach
中的Knockout.js不会遍历我的可观察数组。
在我的HTML中,它具有可观察模型的完美效果:
<div class="field-group">
<label class="popup-label" for="email">Email</label>
<span class="email" data-bind="text: masterVM.employeeVM.Email"></span>
</div>
但是在同一模型中,此代码不起作用:
<ul data-bind="foreach: { data: masterVM.employeeVM.Tags, as: 'tag' }">
<li>
<span class="popup-tag" data-bind="text: tag.tagName"><i class="zmdi zmdi-delete"></i></span>
</li>
</ul>
有两个模型:
Employee
var observableEmployee = function(id, email, tags) {
var self = this;
self.Id = ko.observable(id);
self.Email = ko.observable(email);
self.Tags = ko.observableArray(ko.utils.arrayMap(tags, function(item) {
return new observableTag(item.Id, item.EmployeeId, item.TagId, item.tagName)
}));
self.errors = ko.validation.group(this, {
deep: true
});
self.isValid = ko.computed(function() {
return self.errors().length > 0 ? false : true;
});
}
和标签
var observableTag = function(id, employeeId, tagId, tagName) {
var self = this;
self.Id = ko.observable(id);
self.employeeId = ko.observable(employeeId);
self.tagId = ko.observable(tagId);
self.TagName = ko.observable(tagName);
self.errors = ko.validation.group(this, {
live: true
});
self.isValid = ko.computed(function() {
return self.errors().length > 0 ? false : true;
});
}
和处理程序功能:
var employeeHandler = function () {
var self = this;
self.getEmployeeDetails = function (header) {
$.ajax({
url: masterVM.controller.renderEmployeeDetails,
dataType: 'json',
contentType: 'application/json',
type: 'POST',
data: JSON.stringify({ id: header.data("employeeid") }),
success: function (result) {
masterVM.employeeVM = new observableEmployee(
result.model.Id,
result.model.Email,
result.model.Tags
);
ko.applyBindings(masterVM, $("#employee-planning-selected")[0]);
//header.parent().addClass('open');
//header.next().slideDown('normal');
//hideLoader(header);
console.log('get employee details');
$(document).on('click', "div.employee", onNameCardClick);
},
error: function (xhr, ajaxOptions, thrownError) {
alert('Error!');
}
});
}}
在我的HTML文件中
<script>
masterVM = {
controller: {
renderEmployeeDetails: '@(Html.GetActionUrl<EmployeesController>(c => c.RenderEmployeeDetails(0)))'
},
employeeHandler: new employeeHandler(),
employeeVM: new observableEmployee(0, '', '', '', '')
}
ko.applyBindings(masterVM);
</script>
尝试过类似的操作,但还是一无所获
<!--ko foreach: employeeVM.Tags -->
<span data-bind="text: $data.Tags"></span>
<!-- /ko -->
而且,控制台中没有错误,我使用了KnockouJS上下文调试器,该调试器向我显示了此集合中的元素,即使当我尝试将它们显示为对象时,它也会向我显示一个列表4个元素。
淘汰赛版本:2.3.0
1)。如果要在masterVM
中绑定ko.applyBindings(masterVM)
对象,则无需在数据绑定中再次指定该对象。
所以应该是
foreach: { data: employeeVM.Tags, as: 'tag' }
不是
foreach: { data: masterVM.employeeVM.Tags, as: 'tag' }
((我不确定第一个data-bind="text: masterVM.employeeVM.Email"
的工作方式)
2)。您不需要多次呼叫applyBindings
。如果要更新员工对象,可以将employeeVM
变为可观察对象,并继续在getEmployeeDetails
方法中对其进行更新。
3)您的containerless control flow syntax不起作用。 (<!--ko foreach: employeeVM.Tags -->
)。在此foreach中,$data
是当前Tag
对象in context。因此,应为<span data-bind="text: $data.TagName"></span>
这是代码的最低版本。点击“运行代码段”进行测试。当您单击Update employee
按钮时,我正在更新employeeVM
可观察到的数据,并再次渲染数据。无需再次调用applyBindings
var employeeHandler = function() {
var self = this;
self.getEmployeeDetails = function(header) {
var newEmployee = new observableEmployee(0, '[email protected]', [{
Id: 3,
EmployeeId: 3,
TagId: 3,
tagName: 'Tag Name 3'
}]);
// You need to use employeeVM(newEmployee) instead of employeeVM = newEmployee
// Because employeeVM is an observable.
masterVM.employeeVM(newEmployee);
}
}
var observableEmployee = function(id, email, tags) {
var self = this;
self.Id = ko.observable(id);
self.Email = ko.observable(email);
self.Tags = ko.observableArray(ko.utils.arrayMap(tags, function(item) {
return new observableTag(item.Id, item.EmployeeId, item.TagId, item.tagName)
}));
}
var observableTag = function(id, employeeId, tagId, tagName) {
var self = this;
self.Id = ko.observable(id);
self.employeeId = ko.observable(employeeId);
self.tagId = ko.observable(tagId);
self.TagName = ko.observable(tagName);
}
var masterVM = {
controller: {
renderEmployeeDetails: ''
},
employeeHandler: new employeeHandler(),
// change this to an observable
employeeVM: ko.observable(new observableEmployee(0, '[email protected]', [{
Id: 1,
EmployeeId: 1,
TagId: 1,
tagName: 'Tag name 1'
}]))
}
ko.applyBindings(masterVM);
document.getElementById("button").addEventListener("click", function(e) {
masterVM.employeeHandler.getEmployeeDetails()
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-min.js"></script>
<div class="field-group">
<label class="popup-label" for="email">Email:</label>
<span class="email" data-bind="text: employeeVM().Email"></span>
</div>
<ul data-bind="foreach: { data: employeeVM().Tags, as: 'tag' }">
<li>
<span class="popup-tag" data-bind="text: tag.employeeId"></span> <br>
<span class="popup-tag" data-bind="text: tag.tagId"></span><br>
<span class="popup-tag" data-bind="text: tag.TagName"></span>
</li>
</ul>
<button id="button">Update employee</button>