Objective-C

REST Receive Response in Chunks

See more REST Examples

Demonstrates how to receive a REST HTTP response in chunks.

Note: This example requires Chilkat 10.1.0 or greater.

Objective-C

#import <CkoRest.h>
#import <NSString.h>
#import <CkoFileAccess.h>
#import <CkoBinData.h>

BOOL success = NO;

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

CkoRest *rest = [[CkoRest alloc] init];

// Connect to the web server
BOOL bTls = YES;
int port = 443;
BOOL bAutoReconnect = YES;
success = [rest Connect: @"chilkatsoft.com" port: [NSNumber numberWithInt: port] tls: bTls autoReconnect: bAutoReconnect];
if (success == NO) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

// Send the request.
// This can be *any* kind of request: POST, GET, PUT, etc. using *any* of the Chilkat REST methods that send requests.
// For this example, we'll just GET a simple XML document that is about 274K in size.

success = [rest SendReqNoBody: @"GET" uriPath: @"/hamlet.xml"];
if (success == NO) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

// Get the response header.
int statusCode = [[rest ReadResponseHeader] intValue];
if (statusCode < 0) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

NSLog(@"%@%d",@"response status code = ",statusCode);

NSString *outputFile = @"c:/temp/qa_output/hamlet.xml";

CkoFileAccess *fac = [[CkoFileAccess alloc] init];
success = [fac OpenForWrite: outputFile];
if (statusCode < 0) {
    NSLog(@"%@",fac.LastErrorText);
    return;
}

// Get the response in chunks.
// (Note: There are more efficient ways to simply download a file from a web server, such as by calling Chilkat's Http.Download method.
// The purpose of this method is to show how to receive a response chunk-by-chunk.)
CkoBinData *bd = [[CkoBinData alloc] init];
int status = 1;
while (status == 1) {
    // Read a minimum of 16000 bytes.
    // Note: Because of TLS message lengths, or the possibility of the response being either compressed (gzip/deflate) or in the HTTP chunked encoding,
    // the amount of data received in each call can be greater than the specified min size.
    // Chilkat will return from the call as soon as it has received an amount equal to or more than the specified size,
    // except for the very last chunk, which can be less that the min size or even 0 bytes.

    // The status will be one of three values:
    // -1 = error
    // 0 = received the last chunk of the response.
    // 1 = received a chunk, and more chunks are coming..

    // The received data is *appended* to the contents of the BinData object.
    status = [[rest ReadRespChunkBd: [NSNumber numberWithInt: 16000] bd: bd] intValue];
    if (status >= 0) {
        NSLog(@"%@%d%@",@"Received chunk: ",[bd.NumBytes intValue],@" bytes");
        [fac FileWriteBd: bd offset: [NSNumber numberWithInt: 0] numBytes: [NSNumber numberWithInt: 0]];
        [bd Clear];
    }

}

[fac FileClose];

NSLog(@"%@",@"Success.");