In complex applications, with multiple, intertwined dependencies, updating a single observable might trigger a cascade of computed observables, manual subscriptions, and UI binding updates.These updates can be expensive and inefficient if unnecessary intermediate values are pushed to the view or result in extra computed observable evaluations.When working with Knockout JS, there seem to be many common operations that you need to perform on your view model objects.Internally, Knockout has a number of utility functions used by the library itself, but many of these functions might actually be handy for anyone using the library.After seeing the result, you are immediately reminded that observables are actually functions and that JSON does not contain functions, so the observables are ignored by JSON serializers.
Here’s how notification scheduling differs between the standard, deferred, and rate-limited modes: Deferred updates are turned off by default to provide compatibility with existing applications.
Suppose you add the following function to as many times as you like, and the Ajax call will only happen once after you release your thread back to the Java Script runtime.
Although deferred, asynchronous notifications are generally better because of fewer UI updates, it can be a problem if you need to update the UI immediately.
function App View Model(type) ko.options.defer Updates = true; var vm Deferred = new App View Model('deferred'); ko.options.defer Updates = false; var vm Standard = new App View Model('standard'); ko.apply Bindings([vm Standard, vm Deferred]); properties are later changed.
This is very simple and elegant (and it’s trivial to add yet more observable query parameters that also trigger a refresh automatically whenever they change), but there is a potential efficiency problem.
to turn our observables into a plain object, but we may need to do some additional tweaking before it is ready to send to the server.