foris-js/src/form/hooks.js

/*
 * Copyright (C) 2019 CZ.NIC z.s.p.o. (http://www.nic.cz/)
 *
 * This is free software, licensed under the GNU General Public License v3.
 * See /LICENSE for more information.
 */

import { useCallback, useEffect, useReducer } from "react";
import update from "immutability-helper";

import { useAPIGet } from "api/hooks";
import { useWSForisModule } from "webSockets/hooks";


const FORM_ACTIONS = {
    updateValue: 1,
    resetData: 2,
};

export function useForm(validator, prepData) {

    const [state, dispatch] = useReducer(formReducer, {
        data: null,
        initialData: null,
        errors: {},
    });

    const onFormReload = useCallback((data) => {
        dispatch({
            type: FORM_ACTIONS.resetData,
            data,
            prepData,
            validator,
        });
    }, [prepData, validator]);

    const onFormChangeHandler = useCallback((updateRule) => (event) => {
        dispatch({
            type: FORM_ACTIONS.updateValue,
            value: getChangedValue(event.target),
            updateRule,
            validator,
        });
    }, [validator]);
    return [
        state,
        onFormChangeHandler,
        onFormReload,
    ];
}


function formReducer(state, action) {
    switch (action.type) {
    case FORM_ACTIONS.updateValue: {
        const newData = update(state.data, action.updateRule(action.value));
        const errors = action.validator(newData);
        return {
            ...state,
            data: newData,
            errors,
        };
    }
    case FORM_ACTIONS.resetData: {
        if (!action.data) return { ...state, initialData: state.data };
        const prepData = action.prepData ? action.prepData(action.data) : action.data;
        return {
            data: prepData,
            initialData: prepData,
            errors: action.data ? action.validator(prepData) : undefined,
        };
    }
    default: {
        throw new Error();
    }
    }
}

function getChangedValue(target) {
    let { value } = target;
    if (target.type === "checkbox") {
        value = target.checked;
    } else if (target.type === "number") {
        const parsedValue = parseInt(value);
        value = isNaN(parsedValue) ? value : parsedValue;
    }
    return value;
}

export function useForisModule(ws, config) {
    const [APIGetState, get] = useAPIGet(config.endpoint);
    const [WSData] = useWSForisModule(ws, config.wsModule, config.wsAction);

    useEffect(() => {
        get();
    }, [WSData, get]);

    return [APIGetState];
}