README.md

hoc-react-loader

This is a higher order component ("HOC"). Its purpose is to call a load callback passed through the props of a component only once (at componentWillMount). This is convenient to load data from a backend for instance. The component shows a loading indicator when it's waiting for the props to be defined. The loading indicator can be changed easily.

Demos

You can test some examples here.

Installation

npm i --save hoc-react-loader

Usage

With this.props

import loader from 'hoc-react-loader'

const Component = ({ data }) => <div>Component {JSON.stringify(data)}</div>

export default loader(Component, { wait: ['data'] })

In this case, the loader waits for this.props.data to be truthy, then mounts its child component and calls this.props.load if it exists. This is useful when the parent has control over the injected data, or when the Component is connected with redux. this.props.load should be injected by the parent component or injected by a Container (redux).

The wait parameter should be an array of props to waits. All these props should become truthy at some point.

Since the LoadingIndicator is not specified, the default LoadingIndicator is displayed while waiting for all the props. Here's an exemple with a specified loader:

import loader from 'hoc-react-loader'

const MyLoadingIndicator = () => <div>Waiting...</div>
const Component = ({ data }) => <div>Component {data}</div>

export default loader(Component, { wait: ['data'], LoadingIndicator: MyLoadingIndicator })

Don't wait

import loader from 'hoc-react-loader'

const Component = ({ data }) => <div>Component {JSON.stringify(data)}</div>

export default loader(Component, { wait: false })

In this example, the loader component doesn't wait for props. this.props.load is called once, but the LoadingIndicator component isn't displayed.

Load as a function parameter

import loader from 'hoc-react-loader'

const Component = ({ data }) => <div>Component {JSON.stringify(data)}</div>

export default loader(Component, { load: () => console.log('here') })

In this case, the loader calls this.props.load if it exists AND the load parameter, resulting in here to be printed.

The default wait parameter value is false. It means that in this example the LoadingIndicator isn't displayed.

Load as a string parameter

import loader from 'hoc-react-loader'

const Component = ({ data }) => <div>Component {JSON.stringify(data)}</div>

export default loader(Component, { load: 'myLoader' })

In this case, the loader calls this.props.myLoader if it exists.

The default wait parameter value is false. It means that in this example the LoadingIndicator isn't displayed.

Wait as a function

The wait parameter can also be a function. Then the context and props are given to it, and it should return the array of props to wait for.