(Visual FoxPro) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loJsonToken
LOCAL loSbAuth
LOCAL loRest
LOCAL lnBAutoReconnect
LOCAL lnSuccess
LOCAL loJson
LOCAL loSbPath
LOCAL lnNumReplacements
LOCAL loSbRequestBody
LOCAL loSbResponseBody

* 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)
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJsonToken = CreateObject('Chilkat.JsonObject')
loJsonToken.LoadFile("qa_data/tokens/paypal.json")

* Build the Authorization request header field value.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbAuth = CreateObject('Chilkat.StringBuilder')
* token_type should be "Bearer"
loSbAuth.Append(loJsonToken.StringOf("token_type"))
loSbAuth.Append(" ")
loSbAuth.Append(loJsonToken.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.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rest')
loRest = CreateObject('Chilkat.Rest')
lnBAutoReconnect = 1
lnSuccess = loRest.Connect("api.sandbox.paypal.com",443,1,lnBAutoReconnect)
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loJsonToken
    RELEASE loSbAuth
    RELEASE loRest
    CANCEL
ENDIF

* ----------------------------------------------------------------------------------------------
* 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:
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.EmitCompact = 0
loJson.UpdateString("subject","Past due")
loJson.UpdateString("note","Canceling invoice")
loJson.UpdateBool("send_to_merchant",1)
loJson.UpdateBool("send_to_payer",1)
? loJson.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.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbPath = CreateObject('Chilkat.StringBuilder')
loSbPath.Append("/v1/invoicing/invoices/invoice_id/cancel")
lnNumReplacements = loSbPath.Replace("invoice_id","INV2-XPWZ-NUTQ-LNWB-P8NC")

loJson.EmitCompact = 1
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbRequestBody = CreateObject('Chilkat.StringBuilder')
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbResponseBody = CreateObject('Chilkat.StringBuilder')

loRest.AddHeader("Content-Type","application/json")
loRest.AddHeader("Authorization",loSbAuth.GetAsString())
loJson.EmitSb(loSbRequestBody)

lnSuccess = loRest.FullRequestSb("POST",loSbPath.GetAsString(),loSbRequestBody,loSbResponseBody)
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loJsonToken
    RELEASE loSbAuth
    RELEASE loRest
    RELEASE loJson
    RELEASE loSbPath
    RELEASE loSbRequestBody
    RELEASE loSbResponseBody
    CANCEL
ENDIF

? "Response Status Code = " + STR(loRest.ResponseStatusCode)

* 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 ((loRest.ResponseStatusCode <> 202) AND (loRest.ResponseStatusCode <> 204)) THEN
    ? loSbResponseBody.GetAsString()
    ? "Failed."
    RELEASE loJsonToken
    RELEASE loSbAuth
    RELEASE loRest
    RELEASE loJson
    RELEASE loSbPath
    RELEASE loSbRequestBody
    RELEASE loSbResponseBody
    CANCEL
ENDIF

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

RELEASE loJsonToken
RELEASE loSbAuth
RELEASE loRest
RELEASE loJson
RELEASE loSbPath
RELEASE loSbRequestBody
RELEASE loSbResponseBody