(Objective-C) REST Stream Multipart Body from File

Demonstrates how to send a multipart/form-data HTTP request, where one of the parts contains data streamed directly from a file. This is good for cases where the file to be uploaded is very large.

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#import <CkoRest.h>
#import <CkoStringBuilder.h>
#import <CkoStream.h>
#import <NSString.h>

// 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 destination web server.
BOOL bTls = YES;
int port = 443;
BOOL bAutoReconnect = YES;
BOOL success = [rest Connect: @"www.somewebserver.com" port: [NSNumber numberWithInt: port] tls: bTls autoReconnect: bAutoReconnect];

// This example will send the following multipart/form-data request.
// The Content-Length is automatically computed and added by Chilkat.

// 	POST /some_path HTTP/1.1
// 	Content-Type: multipart/form-data; boundary=---------------------------735323031399963166993862150
// 	Content-Length: 834
// 
// 	-----------------------------735323031399963166993862150
// 	Content-Disposition: form-data; name="text1"
// 
// 	text 123 abc
// 	-----------------------------735323031399963166993862150
// 	Content-Disposition: form-data; name="text2"
// 
// 	xyz
// 	-----------------------------735323031399963166993862150
// 	Content-Disposition: form-data; name="file1"; filename="a.txt"
// 	Content-Type: text/plain
// 
// 	Content of a.txt.
// 
// 	-----------------------------735323031399963166993862150
// 	Content-Disposition: form-data; name="file2"; filename="a.html"
// 	Content-Type: text/html
// 
// 	<!DOCTYPE html><title>Content of a.html.</title>
// 
// 	-----------------------------735323031399963166993862150
// 	Content-Disposition: form-data; name="file3"; filename="starfish.jpg"
// 	Content-Type: image/jpeg
// 
// 	binary data goes here
// 	-----------------------------735323031399963166993862150--

// Set the Content-Type for the topmost MIME part.
[rest AddHeader: @"Content-Type" value: @"multipart/form-data"];

// Specify each part of the request.
rest.PartSelector = @"1";
[rest AddHeader: @"Content-Disposition" value: @"form-data; name=\"text1\""];
[rest SetMultipartBodyString: @"text 123 abc"];

rest.PartSelector = @"2";
[rest AddHeader: @"Content-Disposition" value: @"form-data; name=\"text2\""];
[rest SetMultipartBodyString: @"xyz"];

rest.PartSelector = @"3";
[rest AddHeader: @"Content-Disposition" value: @"form-data; name=\"file1\"; filename=\"a.txt\""];
[rest AddHeader: @"Content-Type" value: @"text/plain"];
[rest SetMultipartBodyString: @"Content of a.txt."];

rest.PartSelector = @"4";
[rest AddHeader: @"Content-Disposition" value: @"form-data; name=\"file2\"; filename=\"a.html\""];
[rest AddHeader: @"Content-Type" value: @"text/html"];
CkoStringBuilder *sbHtml = [[CkoStringBuilder alloc] init];
[sbHtml LoadFile: @"qa_data/html/a.html" charset: @"utf-8"];
[rest SetMultipartBodySb: sbHtml];

rest.PartSelector = @"5";
[rest AddHeader: @"Content-Disposition" value: @"form-data; name=\"file3\"; filename=\"starfish.jpg\""];
[rest AddHeader: @"Content-Type" value: @"image/jpeg"];

// When the request is sent, stream this part directly from the file.
// This avoids having to load the entire file into memory.
CkoStream *fileStream = [[CkoStream alloc] init];
fileStream.SourceFile = @"qa_data/jpg/starfish.jpg";
[rest SetMultipartBodyStream: fileStream];

NSString *responseBody = [rest FullRequestMultipart: @"POST" uriPath: @"/some_path"];
if (rest.LastMethodSuccess != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

// ...
// ...

// Clear the REST object for any subsequent requests..
[rest ClearAllHeaders];
[rest ClearAllParts];
rest.PartSelector = @"";