This example shows the creation of a simple HTTP GET request with a long-polling function to a remote service that delivers push notifications.

longpoll.agent.nut

// Set up outgoing request object as a global (we may need to cancel it, so we need a reference to it)
request <- http.get(webServiceURL, webServiceHeaders);
 
// Define the response handler
function handleResponse(responseTable) {
    // Called when the imp receives an immediate acknowledgement from the remote service
    if (responseTable.statuscode == 200) {
        // Remote service has responded with 'OK' so decode
        // the response's body 'responseTable.body' and headers 'responseTable.headers'
        // Code omitted for clarity...
    } else {
        // Log an error
        server.log("Error response: " + responseTable.statuscode);
            
        // And cancel the request (since the remote server clearly can't fulfil the push request)
        request.cancel();
    }
}
 
// Define the long-poll response handler
function handleLongResponse(responseTable) {
    // Called when the imp receives a long-term response from the remote service
    // This might be information 'pushed' to the device, so we need to re-submit
    // the request in order to receive future notifications
    if (responseTable.statuscode == 200) {
        // Remote service has responded with 'OK' so decode
        // the response's body 'responseTable.body' and headers 'responseTable.headers'
        // Code omitted for clarity...
    } else {
        // Log an error
        server.log("Error response: " + responseTable.statuscode);
    }
        
    // Re-submit the long-poll request. We must initialize a new request for this
    request = http.get(webServiceURL, webServiceHeaders);
    request.sendasync(handleResponse, handleLongResponse);
}
 
// Send the request asynchronously. This will not block the imp CPU
request.sendasync(handleResponse, handleLongResponse);