compose(...functions)
Composes functions from right to left.
This is a functional programming utility, and is included in Redux as a convenience. You might want to use it to apply several store enhancers in a row.
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Arguments- (arguments): The functions to compose. Each function is expected to accept a single parameter. Its return value will be provided as an argument to the function standing to the left, and so on. The exception is the right-most argument which can accept multiple parameters, as it will provide the signature for the resulting composed function.
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Returns(Function): The final function obtained by composing the given functions from right to left.
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ExampleThis example demonstrates how to use compose
to enhance a store with applyMiddleware
and a few developer tools from the redux-devtools package.
import { createStore, applyMiddleware, compose } from 'redux'import thunk from 'redux-thunk'import DevTools from './containers/DevTools'import reducer from '../reducers'
const store = createStore( reducer, compose(applyMiddleware(thunk), DevTools.instrument()))
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Tips- All
compose
does is let you write deeply nested function transformations without the rightward drift of the code. Don't give it too much credit!