Function is_http_backend

webiojs/src/session.ts:356–369

(backend_addr: string)

*   is_http_backend('http://localhost:8080/io').then(function(http_backend){ });
* */
export function is_http_backend(backend_addr: string) {
    let url = new URL(backend_addr);
    let protocol = url.protocol || window.location.protocol;
    url.protocol = protocol.replace('wss', 'https').replace('ws', 'http');
    backend_addr = url.href;

    return new Promise(function (resolve, reject) {
        $.get(backend_addr, {test: 1}, undefined, 'html').done(function (data: string) {
            resolve(data === 'ok');
        }).fail(function (e: JQuery.jqXHR) {
            resolve(false);
        });
    });
}


// Send data to backend