Handy little helper to create proper HOC functions complete with hoisted statics and forwarded refs
As defined in the React documentation, a Higher Order Component, or HOC, is a function that returns a React component
that wraps a specified child component and often provides augmented functionality. Implementing HOCs can be hard,
especially when considering hoisting statics, managing ref
forwarding, and handling display name. addhoc
aims to
handle these challenges for you.
addhoc
creates HOC functions that automatically:
- pass through unrelated
props
- wrap the display name for easy debugging
- hoist non-React statics
- forward
refs
npm install addhoc
/**** Public API ****/
// This is the main exported entrypoint
addhoc(renderFn: Function, [name: String = 'WithHOC'], [...extraArgs]): Function
/**** Signatures, not exported API ****/
// This is the signature of the renderFn parameter to addhoc()
renderFn(getWrappedComponent: Function, [...extraArgs]): React.Component
// This is the signature of the getWrappedComponent parameter to renderFn()
getWrappedComponent([additionalProps: Object]): React.Component
addhoc
is a function that returns a HOC function. To construct your HOC, you simply pass a callback that acts as the
render function of your top-level component. Your callback is provided a function parameter that returns the wrapped
child that's initially provided to the HOC. You can call that callback with an object of props
to add to the wrapped
component.
import addhoc from 'addhoc';
import MyComponent from './my-component';
const withFooProp = addhoc(getWrappedComponent => getWrappedComponent({ foo: true }), 'WithFooProp');
const MyComponentWithFoo = withFooProp(MyComponent);
// Rendering a MyComponentWithFoo will create a MyComponent with prop foo = true
import React from 'react';
import addhoc from 'addhoc';
import MyComponent from './my-component';
const withDiv = addhoc(getWrappedComponent =>
<div>
{ getWrappedComponent() }
</div>, 'WithDiv');
const MyComponentWithDiv = withDiv(MyComponent);
// Rendering a MyComponentWithDiv will render a div that wraps a MyComponent
import React from 'react';
import addhoc from 'addhoc';
import MyComponent from './my-component';
const MyContext = React.createContext('DefaultValue');
const withMyContext = addhoc(getWrappedComponent =>
<MyContext.Consumer>
{ value => getWrappedComponent({ value }) }
</MyContext.Consumer>, 'WithMyContext');
const MyComponentWithMyContext = withMyContext(MyComponent);
// ...
render() {
return <MyContext.Provider value='ProvidedValue'>
<MyComponentWithMyContext />
</MyContext.Provider>
}
// Now, the MyComponentWithMyContext automatically gets a prop called `value` that gets the context value passed in from
// the context.
Sometimes, you want to set some values as part of assembling the HOC and have those available in your render function.
You can pass arbitrary parameters after the name
param to addhoc
and they'll be passed through as additional
parameters to your render function:
import addhoc from 'addhoc';
import MyComponent from './my-component';
const withFooProp = addhoc((getWrappedComponent, extra) => getWrappedComponent({ foo: extra }), 'WithFoo', 'EXTRA');
const MyComponentWithFoo = withFooProp(MyComponent);
// Rendering a MyComponentWithFoo will get a `foo` prop with value `EXTRA`
npm test