Using Knockout Computed Observables for Declarative UI Updates
Learn how Knockout computed observables automatically keep the UI in sync with model changes, see a concrete example, and understand performance limits and common pitfalls.
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javascriptShould a Knockout computed that reads non-observable state like clock time be a pureComputed?
I'm designing a view model in Knockout 3.x where a computed value derives partly from observables and partly from state that Knockout cannot track, such as the current clock time or a value held in an external store outside the observable graph. My understanding is that ko.pureComputed sleeps whenever it has no subscribers: it stops re-evaluating, ignores ch
ko.computed or ko.pureComputed for view models with many rarely-observed computeds?
I'm designing a Knockout view-model layer (Knockout 3.5.x) where a large list rendered with foreach produces many item view models, each carrying several computed values. Most of those computeds are only observed while their row is visible or bound, and the view models themselves can live for a long time. The documented trade-off is clear in outline: ko.comp