knockout.js

问题 This isn't an ideal situation, but due to another knockout binding I am using I am in a situation where I am needing to get the element an observable is bound to, if it is indeed bound to anything. So is there a way to do this? == Update == I didn't want to add any extra context incase it confuses the question, but as it may get an answer more in line with expectations here is the scenario. I am using the knockout validation binding, which exposes all the errors using the ko.validation.group

问题 How do I use KnockoutJS to bind a dictionary collection to a select list. If my "Destinations" dictionary looks like this in JSON: {"Europe":"Europe incl Egypt, Turkey & Tunisia","ANZO":"Australia & New Zealand","WorldwideUSA":"Worldwide (incl USA & Canada)"} How do I bind this to a select list. Something like this: data_bind="value: Destination, options: Destinations.Value, optionsText: Destinations.Key" 回答1: Typically, when dealing with a dictionary, you will want to map it to an array

问题 How do you replace a given index in an observableArray with another element. I have: ViewModel.Elements()[index] how can i replace it with another element. 回答1: observableArrays do have a replace method. This takes in the old item and the new item. So, you would call it like: ViewModel.Elements.replace(ViewModel.Elements()[index], yourNewElement); Internally, this just sets that index to your new item and calls valueHasMutated() to notify any potential subscribers. 回答2: It's a little late by

问题 I found a similar question/answer here: How to render a table with some fixed and some dynamic columns But it does not completely solve my problem. I am trying to figure out how I can limit the number of dynamic columns to 5 per row and if there are more than 5 items in the view model, make a new row and repeat for all groups of 5 in the array. For example: var vm = { item: { name: 'test1' }, item: { name: 'test2' }, item: { name: 'test3' }, item: { name: 'test4' }, item: { name: 'test5' },

问题 Question says it all really. I want to copy an observable array to another in KnockoutJS. 回答1: To clone an observableArray you would want to do: var viewModel = { array1: ko.observableArray(["one", "two"]), array2: ko.observableArray() }; viewModel.clone = function() { viewModel.array1(viewModel.array2.slice(0)); }; If you want to just do a copy, then you would do: viewModel.array1(viewModel.array2()); The problem with the second example is that the underlying array is the same, so pushing to

问题 I've found engines, plugins and functions to load external templates, but I'm wondering if there's a simpler way to do it. Something like this? templates.html <script id="testTemplate" type="text/html"> <div>this is a div</div> </script> index.html <div id="templateContainer"></div> <script> $(document).ready(function() { $("#templateContainer").load("templates.html"); } </script> Will this work? Are there any "gotchas"? 回答1: Here's what I use to load a template file that contains a

问题 When using: var dataToSave = ko.toJSON(myViewModel); .. is it possible to not serialize values that are null? Serializing my current viewModel creates around 500Kb of JSON most of which is ends up like: "SomeObject": { "Property1": 12345, "Property2": "Sometext", "Property3": null, "Property4": null, "Property5": null, "Property6": null, "Property7": null, "Property8": null, "Property9": false } If I could get the serializer to ignore null values then this could be reduced down to:

问题 Is there a simple way to bind the textbox of a div to change based on the text value of the selected option in a dropdown on the same page? <div data-bind="text: dropdownValue"></div> <select> <option value="1">Value1</option> <option value="2">Value2</option> </select> Please note, I don't want to put the values into the select element using javascript. I'd like to bind to the value straight from the HTML. I can also include jQuery to make it work. 回答1: I was looking for similar

问题 I'm having a small issue with setting the initial value of a dropdown. The code below is the view model definition and the initialization in $(document).ready . I have an array called sourceMaterialTypes and a selectedSourceMaterialType representing the selected value of that array. I am initializing the view model with values from the (ASP.Net MVC) Model and ViewBag. var viewModel = { sourceMaterialTypes : ko.observableArray(@Html.Raw(Json.Encode(ViewBag.SourceMaterialTypes))),

问题 I have an input that has a knockout binding to the value. When I update the value using jquery's .val() method, the changed value is not reflected in the viewModel. I need to use jQuery to set this value. How can I trigger the update to the viewModel? 回答1: .val() does not trigger the change event. So, you can just do . val("blah").change() for KO to pick up the changes. 来源： https://stackoverflow.com/questions/7018885/knockout-js-bound-input-value-not-updated-when-i-use-jquery-valxyz