alcaeus/FetchUtil.js

Hydra Core hypermedia-aware client library

import li from 'parse-link-header';
import ResponseWrapper from './ResponseWrapper.js';
import { merge } from './helpers/MergeHeaders.js';
import * as Constants from './Constants.js';
function requestAcceptHeaders(sinkMap) {
    return [...sinkMap.keys()].join(', ');
}
export default function (_fetch, _Headers) {
    async function getResponse(effectiveUri, { method = 'get', headers = {}, body, parsers, ...rest }) {
        const defaultHeaders = {
            accept: requestAcceptHeaders(parsers),
        };
        const requestInit = {
            method,
            ...filterRequestInit(rest),
        };
        if (method.toLowerCase() !== 'get') {
            requestInit.body = body;
        }
        requestInit.headers = merge(new _Headers(defaultHeaders), new _Headers(headers), _Headers);
        const res = await _fetch(effectiveUri, requestInit);
        const linkHeaders = res.headers.get(Constants.Headers.Link) || '';
        const links = li(linkHeaders) || {};
        let jsonLdContext;
        const context = links[Constants.LinkRelations.context];
        if (typeof context !== 'undefined') {
            jsonLdContext = await _fetch(context.url).then(res => res.json());
        }
        return new ResponseWrapper(effectiveUri, res, parsers, jsonLdContext);
    }
    function resource(uri, requestInit) {
        return getResponse(uri, {
            method: 'get',
            ...requestInit,
        });
    }
    function operation(method, uri, requestInit) {
        return getResponse(uri, { method, ...requestInit });
    }
    return {
        resource,
        operation,
    };
}
function filterRequestInit(arg = {}) {
    const { headers, body, method, redirect, ...rest } = arg;
    return rest;
}