Function fetch

examples/io/streams/examples/fetch/fetch.js:192–300

(href, info = {})

}

function fetch(href, info = {}) {
	return new Promise((resolveResponse, rejectResponse) => {
		let url = new URL(href);
		if ((url.protocol != "http:") && (url.protocol != "https:"))
			rejectResponse(new URIError("only http or https"));
		let method = info.method;
		let headers = info.headers;
		let body = info.body;
		let length = 0;
		if ((method == "POST") || (method == "PUT") || (method == "PATCH")) {
			body = info.body;
			if (body == undefined) 
				rejectResponse(new URIError(method + " no body"));
			else if (!(body instanceof ArrayBuffer)) {
				body = body.toString();
				body = ArrayBuffer.fromString(body);
			}
			if (!headers)
				headers = new Headers();
			else {
				if (!(headers instanceof Headers)) {
					const h = new Headers();
					for (const name in headers)
						h.set(name.toLowerCase(), headers[name]);
					headers = h;
				}
				length = headers.get("content-length");
				if (length == undefined) {
					headers = new Headers(headers);
					length = body.byteLength;
					headers.set("content-length", length);
				}
			}
		}
		let readableController = null;
		let redirected = false;
		let offset = 0;
		let buffer = null;
		if (info.signal) {
			info.signal.addEventListener("abort", event => {
				if (readableController) {
					readableController.error(event.signal.reason);
					readableController = null;
				}
				else
					rejectResponse(event.signal.reason);
			});
		}
		const options = {
			method,
			headers,
			onHeaders(status, headers) {
				if ((301 === status) || (308 === status) || (302 === status) || (303 === status) || (307 === status)) {
					url = new URL(headers.get("location"));
					redirected = this.redirected = true;
					offset = 0;
					return;
				}