KnockoutJS-更新ViewModel/映射插件 [英] KnockoutJS - Update ViewModel / Mapping Plugin

问题描述

1. 在页面加载时，我得到一个模型，并使用ko.mapping.fromJS(myObject)将其转换为viewModel.
2. 如果用户单击按钮，我想从服务器获取更新的数据
3. 现在我要应用这些更新

1. On page load i get a Model and convert that using ko.mapping.fromJS(myObject) to a viewModel.
2. If the user clicks a button i want to get updated data from the server
3. Now i want to apply theese updates

如果我使用ko.applyBindings(viewModel);，它将完美地更新ui.但是，它再次添​​加了相同的事件.因此，如果用户单击该按钮，则事件将被触发两次，第三次，依此类推.

If i use ko.applyBindings(viewModel); it updates the ui perfectly. But it adds the same events again. So if the user clicks the button, the event gets fired twice, third and so on.

var viewModel;

function update() 
{
    $.ajax({
        url: '...',
        type: "GET",
        statusCode: {
            200: function (data) {
                 viewModel = ko.mapping.fromJS(data);
                 ko.applyBindings(viewModel);
            }
        }
    });    
}

// first call after page load
update();

// user click
$("#myButton").click(function() {
    update(); 
});

更新

Steve Greatrex 您可以发布自定义绑定实现吗?

Steve Greatrex Could you post your custom binding implementation?

ko.bindingHandlers.domBinding = {
    init: function (element, valueAccessor, allBindingsAccessor, viewModel) {
        viewModel.domElement = element;
    },
    update: function (element, valueAccessor, allBindingsAccessor, viewModel) {
        viewModel.domElement = element;
    },
};

推荐答案

如果您查看映射文档，您可以为映射指定目标.

If you look at the 'Specifying the update target' on the mapping documentation, you can specify a target for the mapping.

这应该意味着您可以说:

This should mean that you can say:

if (!viewModel)
   viewModel = ko.mapping.fromJS(data);
else
   ko.mapping.fromJS(data, {}, viewModel); 

这样，您将在初始加载时创建视图模型，然后为以后的所有加载更新该视图模型.

This way you will create a view model on the initial load, then update that view model for any subsequent loads.

这篇关于KnockoutJS-更新ViewModel/映射插件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！