app/nextjs/data/api.js

import fetch from 'isomorphic-unfetch'

//TODO: 'isomorphic-unfetch' :how to set default headers ?
//   var obj = {
//     method: 'GET',
//     mode: 'no-cors',
//     // headers: {
//     //     'Access-Control-Request-Headers': 'Authorization',
//     //     'Authorization': 'Basic amFzcGVyYWRtaW46amFzcGVyYWRtaW4=',
//     //     'Content-Type': 'application/json',
//     //     'Origin': ''
//     // },
//     credentials: 'include'
//   };

export default {
    ads: {
        fetchAd: async (id) => {
            const res = await fetch(`http://localhost/app_dev.php/api/ads/${id}`)
            const offre = await res.json()

            return { offre: offre.data }
        },
        fetchAds: async (limit = "", order = "", keyword = "", offset = 1) => {
            var obj = {
                method: 'GET',
                //mode : 'no-cors', 
                headers: {
                    // 'Access-Control-Request-Headers': 'Authorization',
                    // 'Authorization': 'Basic amFzcGVyYWRtaW46amFzcGVyYWRtaW4=',
                    'Content-Type': 'application/json',
                    'Origin': ''
                },
                credentials: 'include'
            };

            let url = `http://localhost/app_dev.php/api/ads?offset=${offset}`;
            if (limit != "") {
                url = url + `&limit=${limit}`;
            }
            if (order != "") {
                url = url + `&order=${order}`;
            }
            if (keyword != "") {
                url = url + `&keyword=${keyword}`;
            }
            const res = await fetch(url, obj);
            const show = await res.json();
            return show.data;
        }

    }
}