preact-context-provider

A generic <Provider /> for preact. It exposes any props you pass it into context. Also provides a merging variant <MergingProvider />, and utility functions provide and mergingProvide

Usage

Install it via npm:

1npm install --save preact-context-provider
2
3# or, for Preact X support
4npm install --save preact-context-provider@preactx

Then import it and use:

1import Provider from 'preact-context-provider';
2
3let OBJ = { a: 'b' };
4
5const App = (props, context) => {
6	// now it's exposed to context!
7	console.log(context.obj === OBJ) // true
8};
9
10render(
11	<Provider obj={OBJ}>
12		<App />
13	</Provider>
14);

Preact Version Support

By default, the master branch of this repo supports preact 9 and below, and is published in normal patch/minor/major releases to the latest tag in npm. Support for preact X (versions 10+ of preact) is handled in the preactX branch and are always published to the preactx tag in npm. When preact X obtains widespread adoption, the master branch of this project will support preact X and a new major version under latest tag will be published to in npm.

API

Table of Contents

• Provider
  • Parameters
  • Examples
• MergingProvider
  • Parameters
  • Examples
• provide
  • Parameters
  • Examples
• mergingProvide
  • Parameters
  • Examples

Provider

Adds all passed props, children into context, making them available to all descendants.

To learn about context, see the React Docs.

Parameters

• props Object All props are exposed as properties in context, except children

Examples

1const Demo = (props, context) => {
2  console.log(context);  // "{ a: 'b' }"
3};
4render(
5  <Provider a="b">
6    <Demo />
7  </Provider>
8);
9//	"{ a: 'b' }"
10
11// lower-level providers override higher providers for any keys that they define
12render(
13  <Provider a={key1: 'foo'} b={key2: 'bar'}>
14    <Provider a={key3: 'buz'} >
15      <Demo />
16    </Provider>
17  </Provider>
18);
19// "{ a: { key3: 'buz' }, b: { key2: 'bar' } }"

MergingProvider

Similar to Provider, but allows a special mergeProps prop to allow parent supplied context keys with the same name as those provided by the current MergingProvider to be deep merged, instead of replaced.

To learn about context, see the React Docs.

Parameters

• props Object All props are exposed as properties in context, except children and mergeProps
  • props.mergeProps Array? If not supplied, all supplied props will be merged with keys already in context. If supplied as an array of strings, it will deep merge any prop names that are present in the array, and missing prop names be overriden by the child like Provider.

Examples

1import Provider, { MergingProvider } from 'preact-context-provider';
2const Demo = (props, context) => {
3  console.log(context);  // "{ a: 'b' }"
4};
5
6// with mergeProps unspecified, all parent context keys are merged with the ones presently supplied, parent values taking precedence
7render(
8  <Provider a={key1: 'foo'}>
9    <MergingProvider a={key2: 'bar'}>
10      <Demo />
11    </MergingProvider>
12  </Provider>
13);
14// "{ a: { key1: 'foo', key2: 'bar' } }"
15
16 // when mergeProps is an array, only specified keys are merged, non-specified keys get their value from current node
17// in this example, only the 'a' context key is merged.  'b' is overwritten by the lower node
18render(
19  <Provider a={key1: 'foo'} b={key2: 'bar'}>
20    <MergingProvider mergeProps={['a']} a={key3: 'baz'} b={key4: 'buz'}>
21      <Demo />
22    </MergingProvider>
23  </Provider>
24);
25// "{ a: { key1: 'foo', key3: 'baz' }, b: {key4: 'buz'} }"

provide

Higher Order Component that wraps components in a Provider for the given context.

Parameters

• ctx Object Properties to pass into context (passed to Provider)

Examples

1import {provide} from 'preact-context-provider';
2const Demo = (props, context) => {
3  console.log(context.a);  // "b"
4};
5const ProvidedDemo = provide({a: "b"})(Demo);
6
7ProvidedDemo.getWrappedComponent() === Demo; // true
8
9render( <ProvidedDemo /> );

Returns Function A function that, given a Child component, wraps it in a Provider component for the given context.

mergingProvide

Higher Order Component that wraps components in a MergingProvider for the given context.

Parameters

• ctx Object Properties to pass into context (passed to MergingProvider)

Examples

1import {mergingProvide} from 'preact-context-provider';
2const Demo = (props, context) => {
3  console.log(context.a);
4};
5const ProvidedDemo = mergingProvide({a: "b"})(Demo);
6
7ProvidedDemo.getWrappedComponent() === Demo; // true
8
9render( <ProvidedDemo /> ); // "b"

Returns Function A function that, given a Child component, wraps it in a MergingProvider component for the given context.