(Swift 3,4,5...) PayPal - Cancel Sent Invoice

Cancels a sent invoice, by ID, and, optionally, sends a notification about the cancellation to the payer, merchant, and Cc: emails.

Note: This example requires Chilkat v9.5.0.65 or greater.

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 v9.5.0.65 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.string(of: "token_type"))
    sbAuth.append(" ")
    sbAuth.append(jsonToken.string(of: "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 the JSON request body containing the reminder information:
    let json = CkoJsonObject()!
    json.emitCompact = false
    json.update("subject", value: "Past due")
    json.update("note", value: "Canceling invoice")
    json.updateBool("send_to_merchant", value: true)
    json.updateBool("send_to_payer", value: true)
    print("\(json.emit()!)")

    // The JSON created by the above code:

    // 	{ 
    // 	  "subject": "Past due",
    // 	  "note": "Canceling invoice",
    // 	  "send_to_merchant": true,
    // 	  "send_to_payer": true
    // 	}

    // Build a path using a previously-sent invoice ID.
    let sbPath = CkoStringBuilder()!
    sbPath.append("/v1/invoicing/invoices/invoice_id/cancel")
    var numReplacements: Int = sbPath.replace("invoice_id", replacement: "INV2-XPWZ-NUTQ-LNWB-P8NC").intValue

    json.emitCompact = true
    let sbRequestBody = CkoStringBuilder()!
    let sbResponseBody = CkoStringBuilder()!

    rest.addHeader("Content-Type", value: "application/json")
    rest.addHeader("Authorization", value: sbAuth.getAsString())
    json.emitSb(sbRequestBody)

    success = rest.fullRequestSb("POST", uriPath: sbPath.getAsString(), requestBody: sbRequestBody, responseBody: sbResponseBody)
    if success != true {
        print("\(rest.lastErrorText!)")
        return
    }

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

    // In our testing, we received a 204 response, which is a success HTTP response code, but 
    // differs from the PayPal REST API reference documentation, which states that a 202 response
    // is expected.  I suspect an error in the PayPal documentation, or in the PayPal responder.
    // Check for either 202 or 204..
    // Did we get a 202 accepted response?
    if (rest.responseStatusCode.intValue != 202) && (rest.responseStatusCode.intValue != 204) {
        print("\(sbResponseBody.getAsString()!)")
        print("Failed.")
        return
    }

    // The 202/204 response should be empty.  (Again, our experience differs from the online PayPal documentation..)
    print("Success.")

}