x-http-client/lib/http/handleHeaders.js

An http client to make it easier to send requests (including JSONP requests) to the server.

var merge = require('x-common-utils/merge');
var isPlainObject = require('x-common-utils/isPlainObject');
var hasOwn = require('../shared/hasOwn');

/**
 * The function to set the request headers.
 *
 * 1. Merge the `options.noCacheHeaders` if needed.
 * 2. Set the request headers if needed.
 *
 * @param {XMLHttpReqeust} xhr The instance of `XMLHttpReqeust`.
 * @param {RequestOption} options The request options.
 */
function handleHeaders(xhr, options) {
    var name;
    var value;
    var headers = isPlainObject(options.headers) ? options.headers : {};

    if (options.noCache) {
        if (isPlainObject(options.noCacheHeaders)) {
            headers = merge(headers, options.noCacheHeaders);
        }
    }

    for (name in headers) {
        if (hasOwn.call(headers, name)) {
            value = headers[name];
            // Only the non-undefined and non-null headers are set
            if (value !== undefined && value !== null) {
                xhr.setRequestHeader(name, value);
            }
        }
    }

    // Set the headers back.
    options.headers = headers;
}

module.exports = handleHeaders;