(Swift 3,4,5...) 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.

Chilkat Downloads for the Swift Programming Language

MAC OS X (Cocoa) Objective-C/Swift Libs

iOS Objective-C/Swift Libs

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

    let rest = CkoRest()!

    // Connect to the destination web server.
    var bTls: Bool = true
    var port: Int = 443
    var bAutoReconnect: Bool = true
    var success: Bool = rest.connect("www.somewebserver.com", port: 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")
    let sbHtml = CkoStringBuilder()!
    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.
    let fileStream = CkoStream()!
    fileStream.sourceFile = "qa_data/jpg/starfish.jpg"
    rest.setMultipartBodyStream(fileStream)

    var responseBody: String? = rest.fullRequestMultipart("POST", uriPath: "/some_path")
    if rest.lastMethodSuccess != true {
        print("\(rest.lastErrorText!)")
        return
    }

    // ...
    // ...

    // Clear the REST object for any subsequent requests..
    rest.clearAllHeaders()
    rest.clearAllParts()
    rest.partSelector = ""

}