From the end result point of view there is no difference between the two call, so you will end up with myArray containing no elements. However there is one small difference (if you don’t care about the different return values): self.myArray([]); will replace the underlying array instance with a newly created empty array. While the … Read more
An observableArray exposes a method called indexOf, which is a wrapper to ko.utils.arrayIndexOf that simply loops through the array looking for the item that you pass to it. So, if you have the item you can do: var viewModel = { items: ko.observableArray([{id: 1, name: “one”}, {id:2, name: “two”}]) }; var item = viewModel.items()[1]; console.log(viewModel.items.indexOf(item)); … Read more
Since you persisted on stating that the lack of ko.observables is not an issue, I’ve looked at it closer. It seems, that you are correct! The change event is fired before the actual value is set. I’m afraid I do not know the reason for this. But there is an easy way to fix this: … Read more
KnockoutJS is open source. From the relevant file: ko.applyBindings = function (viewModelOrBindingContext, rootNode) { // Some code omitted for brevity… if (rootNode && (rootNode.nodeType !== 1) && (rootNode.nodeType !== 8)) throw new Error(“ko.applyBindings: first parameter should be your view model; second parameter should be a DOM node”); rootNode = rootNode || window.document.body; // Make “rootNode” … Read more
When Knockout processes your bindings it first evaluates your expression. If the expression results in an observable, it then evaluates the observable as a convenience to get the final value that the if: works on. So the two following work identically <div data-bind=”if: foo”></div> <div data-bind=”if: foo()”></div> Once you leave the world of simple expressions … Read more
Defining a custom binding handler Its actually pretty easy, just add it (myBindingHandler) to the KnockoutBindingHandlers interface right before you define your custom binding handler. Please note that you have to do make this addition to the interface, within a .d.ts file as of version 1.0 (or possibly earlier). bindingHandlers.d.ts /// <reference path=”typings/knockout/knockout.d.ts” /> interface … Read more
If I understood you right, this is the binding you are looking for. data-bind=”text: isApproved, css: { ‘label’ : true, ‘label-success’ : isApproved(), ‘label-important’: !isApproved() }” I hope it helps.
I think that it would be too much to layout the tips that I have in mind in one answer. I started a series of blog posts on this topic. The first post is here. This post describes a bit how if/with work (copies the children as its template and re-renders using the template whenever … Read more
Pager.js is a URL routing framework built specifically for use with Knockout.js. Make sure you go through the entire Demo to see its full power and flexibility. IMHO, it far exceeds PathJS and Sammy.
.val() does not trigger the change event. So, you can just do .val(“blah”).change() for KO to pick up the changes.