Function web_req_async_download

wasm/web_request.js:147–225

(url, outputPath, ctxId)

}

var web_req_async_download = function (url, outputPath, ctxId) {
    create_web_ctx_if_needed(ctxId);
    var urlCpy = url;
    url = web_req_build_url(url, ctxId);

    var headers = new Headers();
    for (var i = 0; i < web_req_ctxs[ctxId].headers.length; i++) {
        headers.append(web_req_ctxs[ctxId].headers[i].key, web_req_ctxs[ctxId].headers[i].value);
    }

    var payload = web_req_get_payload(ctxId);

    var options = {
        method: web_req_ctxs[ctxId].method,
        headers: headers,
    };
    if (web_req_ctxs[ctxId].method != "GET" && web_req_ctxs[ctxId].method != "HEAD") {
        options.body = payload ?? web_req_ctxs[ctxId].formdata ?? web_req_ctxs[ctxId].ody;
    }

    const controller = new AbortController();
    setTimeout(() => controller.abort(), web_req_ctxs[ctxId].timeout);
    options.signal = controller.signal;

    // TODO: upload progress callback support for Fetch API
    var use_download_callback = web_req_ctxs[ctxId].use_download_callback;

    fetch(url, options)
        .then(async (response) => {
            if (!use_download_callback) {
                return response;
            }
            if (!response.ok || !response.body) {
                // nothing to process
                return response;
            }
            const contentEncoding = response.headers.get('content-encoding');
            const contentLength = response.headers.get(contentEncoding ? 'x-file-size' : 'content-length');
            if (contentLength === null) {
                return response;
            }
            const total = parseInt(contentLength, 10);
            if (total == 0) {
                return response;
            }

            let loaded = 0;
            return new Response(
                new ReadableStream({
                    async start(controller) {
                        const reader = response.body.getReader();
                        for (; ;) {
                            const { done, value } = await reader.read();
                            if (done) {
                                break;
                            }
                            loaded += value.byteLength;
                            var v = loaded / total;