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So i've read that observables are looking to overtake promises in terms of usage in some of upcoming JavaScript MVC's:
What is the difference between observables and promises?
Updated: Apologies! removed my falsy statement.
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Often Observable is preferred over Promise because it provides the features of Promise and more. With Observable it doesn't matter if you want to handle 0, 1, or multiple events. You can utilize the same API in each case. Observable also has the advantage over Promise to be cancellable.
Observable JavaScript represents a progressive way of handling events, async the activity, and multiple values in JavaScript. These observables are just the functions that throw values and Objects known as observers subscribe to such values that define the callback functions such as error(), next() and complete().
A Promise is a JavaScript object that links producing code and consuming code.
Observables are not executed until a consumer subscribes. The subscribe() executes the defined behavior once, and it can be called again. Each subscription has its own computation. Resubscription causes recomputation of values.
What is the difference between observables and promises?
Simply put: A promise resolves to a single value asynchronously, an observable resolves to (or emits) multiple values asynchronously (over time).
Concrete examples:
More information can be found here: http://reactivex.io/intro.html
i've read that observables are looking to overtake promises
Unlikely. Observables might be the better solution to certain problems, but that doesn't make promises obsolete (if that's what you mean).
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Promises are a representation of 1 future value. Observables are a representation for a possibly infinite amount of values.
Promises will trigger the fetching of that value immediately upon creation. Observables will only start producing values when you subscribe to them. (Unless it's a hot observable, but that's outside the scope of this question)
Promises are designed to represent AJAX calls. Observables are designed to represent anything: events, data from databases, data from ajax calls, (possibly infinite) sequences, etc.
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