(Swift 2) PayPal Generate QR Code

Generates a QR code for an invoice, by ID.

The QR code is a PNG image in Base64-encoded format that corresponds to the invoice ID.

Note: A QR code can only be generated for an invoice that has been both created and sent.

See also Generate QR Code

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // Note: Requires Chilkat v9.5.0.64 or greater.

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

    // Load our previously obtained access token. (see PayPal OAuth2 Access Token)
    let jsonToken = CkoJsonObject()
    jsonToken.LoadFile("qa_data/tokens/paypal.json")

    // Build the Authorization request header field value.
    let sbAuth = CkoStringBuilder()
    // token_type should be "Bearer"
    sbAuth.Append(jsonToken.StringOf("token_type"))
    sbAuth.Append(" ")
    sbAuth.Append(jsonToken.StringOf("access_token"))

    // Make the initial connection.
    // A single REST object, once connected, can be used for many PayPal REST API calls.
    // The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    // then it will be automatically re-established as needed.
    let rest = CkoRest()
    var bAutoReconnect: Bool = true
    var success: Bool = rest.Connect("api.sandbox.paypal.com", port: 443, tls: true, autoReconnect: bAutoReconnect)
    if success != true {
        print("\(rest.LastErrorText)")
        return
    }

    // ----------------------------------------------------------------------------------------------
    // The code above this comment could be placed inside a function/subroutine within the application
    // because the connection does not need to be made for every request.  Once the connection is made
    // the app may send many requests..
    // ----------------------------------------------------------------------------------------------

    // Build a path using an invoice ID.
    let sbPath = CkoStringBuilder()
    sbPath.Append("/v1/invoicing/invoices/invoice_id/qr-code")
    var numReplacements: Int = sbPath.Replace("invoice_id", replacement: "INV2-ZG2H-HKAW-PMWU-N6ZR").intValue

    rest.AddHeader("Authorization", value: sbAuth.GetAsString())
    // A 500x500 image results in a PNG file of approx. 4K bytes in size.
    rest.AddQueryParam("width", value: "500")
    rest.AddQueryParam("height", value: "500")
    rest.AddQueryParam("action", value: "pay")

    // Send the GET request and get the PNG image data as base64.
    // A successful JSON response looks like this:
    // {"image":"iVBORw0KGgoAA....AASUVORK5CYII="}
    let sbJsonResponse = CkoStringBuilder()
    success = rest.FullRequestNoBodySb("GET", uriPath: sbPath.GetAsString(), sb: sbJsonResponse)
    if success != true {
        print("\(rest.LastErrorText)")
        return
    }

    let json = CkoJsonObject()
    json.EmitCompact = false
    json.LoadSb(sbJsonResponse)

    print("Response Status Code = \(rest.ResponseStatusCode.intValue)")

    // Did we get a 200 success response?
    if rest.ResponseStatusCode.intValue != 200 {
        print("\(json.Emit())")
        print("Failed.")
        return
    }

    // If the 200 response is received, the response body contains the PNG data.
    // Save the PNG to a file.
    let pngData = CkoBinData()
    pngData.AppendEncoded(json.StringOf("image"), encoding: "base64")
    success = pngData.WriteFile("qa_output/paypal_qr_code.png")
    if success == false {
        print("Failed to save PNG file.")
        return
    }

    print("Success.")

}