Passing a function with React Context API to child component nested deep in the tree

Question

I'm using React Context API for the first time. I have a table that generates a list of clients. Originally, I stored the clients in an array in state, and in the same page I had a function that sorted the clients based on click.

I have moved the clients into context rather than in state of the actual page where the table is, but now of course my sort function no longer works. What I need to be able to do is use the same function, but organize the array that is in the context state instead.

Original function:

onSortClient = column => e => {
        const direction = this.state.sort.column
            ? this.state.sort.direction === "asc"
                ? "desc"
                : "asc"
            : "desc";
        const sortedData = this.state.clients.sort((a, b) => {
            if (column === "client_name") {
                const nameA = a.client_name.toUpperCase();
                const nameB = b.client_name.toUpperCase();
                if (nameA < nameB) {
                    return -1;
                }
                if (nameA > nameB) {
                    return 1;
                }

                return 0;
            }
            return 0;
        });

        if (direction === "desc") {
            sortedData.reverse();
        }

        this.setState({
            clients: sortedData,
            sort: {
                column,
                direction
            }
        });
    };

My context file:

import React, { Component } from "react";
import axios from "axios";

const Context = React.createContext();

const Reducer = (state, action) => {
    switch (action.type) {
        case "DELETE_CLIENT":
            console.log(action.payload);
            return {
                ...state,
                clients: state.clients.filter(client => client.id !== action.payload)
            };
        case "ADD_CLIENT":
            return {
                ...state,
                clients: [action.payload, ...state.clients]
            };
        case "UPDATE_CLIENT":
            console.log(action.payload);
            return {
                ...state,
                clients: state.clients.map(
                    client =>
                        client.id === action.payload.id ? (client = action.payload) : client
                )
            };

        default:
            return state;
    }
};

export class Provider extends Component {
    state = {
        clients: [],
        loaded: false,
        dispatch: action => {
            this.setState(state => Reducer(state, action));
        }
    };

    async componentDidMount() {
        let localToken = localStorage.getItem("iod_tkn");

        const res = await axios({
            url: "/users/get_clients",
            method: "get",
            headers: {
                Authorization: localToken
            }
        });

        this.setState({
            clients: res.data,
            loaded: true
        });
    }


    render() {
        return (
            <Context.Provider onSortClient={this.onSortClient} value={this.state}>
                {this.props.children}
            </Context.Provider>
        );
    }
}

export const Consumer = Context.Consumer;

Solution

Maybe something like that?

<Context.Provider
    value={{
        state: this.state,
        onSortClient: this.onSortClient,
    }}
>
    {this.props.children}
</Context.Provider>

So, value.state will be your state, value.onSortClient will be your function.

Comments

[acd37]

If you're pretty good at React, I have another question that nobody has been able to solve yet :) stackoverflow.com/questions/51994498/…

[user2918201]

I feel it necessary to point out that if you use this code as is, every component that consumes this state will re-render every time this component re-renders. This is because you are creating a new object to pass to value every time this renders. See: reactjs.org/docs/context.html#caveats