(JavaScript) REST Read Binary Response into BinData Object (Amazon S3)

Demonstrates how to make a REST call that returns a binary response body. This example is valid for files that fit in memory. The example shows how to download a JPG from the Amazon S3 service.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

var rest = new CkRest();

// Connect to the Amazon AWS REST server.
var bTls = true;
var port = 443;
var bAutoReconnect = true;
success = rest.Connect("s3.amazonaws.com",port,bTls,bAutoReconnect);

// ----------------------------------------------------------------------------
// Important: For buckets created in regions outside us-east-1,
// there are three important changes that need to be made.
// See Working with S3 Buckets in Non-us-east-1 Regions for the details.
// ----------------------------------------------------------------------------

// Provide AWS credentials for the REST call.
var authAws = new CkAuthAws();
authAws.AccessKey = "AWS_ACCESS_KEY";
authAws.SecretKey = "AWS_SECRET_KEY";
authAws.ServiceName = "s3";
success = rest.SetAuthAws(authAws);

// Set the bucket name via the HOST header.
// In this case, the bucket name is "chilkat100".
rest.Host = "chilkat100.s3.amazonaws.com";

// Send the request to download the JPG.
success = rest.SendReqNoBody("GET","/starfish.jpg");
if (success !== true) {
    console.log(rest.LastErrorText);
    return;
}

// Read the response header.
var responseStatusCode = rest.ReadResponseHeader();
if (responseStatusCode < 0) {
    console.log(rest.LastErrorText);
    return;
}

console.log("Response status code = " + responseStatusCode);

// We expect a 200 response status if the JPG data is coming.
// Otherwise, we'll get a string response body with an error message(or no response body).
if (responseStatusCode !== 200) {
    var errResponse = rest.ReadRespBodyString();
    if (rest.LastMethodSuccess !== true) {
        console.log(rest.LastErrorText);
    }
    else {
        console.log(errResponse);
    }

    return;
}

var bdBody = new CkBinData();
success = rest.ReadRespBd(bdBody);
if (success == false) {
    console.log(rest.LastErrorText);
    return;
}

// Save the contents of the response body to a file.
success = bdBody.WriteFile("qa_output/starfish.jpg");
if (success == true) {
    console.log("Success");
}
else {
    console.log("Failed to write file.");
}