lbry-desktop/ui/js/jsonrpc.js

const jsonrpc = {};

jsonrpc.call = function(
	connectionString,
	method,
	params,
	callback,
	errorCallback,
	connectFailedCallback,
	timeout
) {
	var xhr = new XMLHttpRequest();
	if (typeof connectFailedCallback !== 'undefined') {
		if (timeout) {
			xhr.timeout = timeout;
		}

		xhr.addEventListener('error', function(e) {
			connectFailedCallback(e);
		});
		xhr.addEventListener('timeout', function() {
			connectFailedCallback(
				new Error(__('XMLHttpRequest connection timed out'))
			);
		});
	}
	xhr.addEventListener('load', function() {
		var response = JSON.parse(xhr.responseText);

		if (response.error) {
			if (errorCallback) {
				errorCallback(response.error);
			} else {
				var errorEvent = new CustomEvent('unhandledError', {
					detail: {
						connectionString: connectionString,
						method: method,
						params: params,
						code: response.error.code,
						message: response.error.message,
						data: response.error.data
					}
				});
				document.dispatchEvent(errorEvent);
			}
		} else if (callback) {
			callback(response.result);
		}
	});

	if (connectFailedCallback) {
		xhr.addEventListener('error', function(event) {
			connectFailedCallback(event);
		});
	} else {
		xhr.addEventListener('error', function(event) {
			var errorEvent = new CustomEvent('unhandledError', {
				detail: {
					connectionString: connectionString,
					method: method,
					params: params,
					code: xhr.status,
					message: __('Connection to API server failed')
				}
			});
			document.dispatchEvent(errorEvent);
		});
	}

	const counter = parseInt(sessionStorage.getItem('JSONRPCCounter') || 0);

	xhr.open('POST', connectionString, true);
	xhr.send(
		JSON.stringify({
			jsonrpc: '2.0',
			method: method,
			params: params,
			id: counter
		})
	);

	sessionStorage.setItem('JSONRPCCounter', counter + 1);

	return xhr;
};

export default jsonrpc;