Xbase++
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.
Chilkat Xbase++ Downloads

Xbase++
LOCAL nSuccess
LOCAL oJsonToken
LOCAL oSbAuth
LOCAL oRest
LOCAL nBAutoReconnect
LOCAL oSbPath
LOCAL nNumReplacements
LOCAL oSbJsonResponse
LOCAL oJson
LOCAL oPngData

nSuccess := 0

//  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)
oJsonToken := CreateObject("Chilkat.JsonObject")
oJsonToken:LoadFile("qa_data/tokens/paypal.json")

//  Build the Authorization request header field value.
oSbAuth := CreateObject("Chilkat.StringBuilder")
//  token_type should be "Bearer"
oSbAuth:Append(oJsonToken:StringOf("token_type"))
oSbAuth:Append(" ")
oSbAuth:Append(oJsonToken: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.
oRest := CreateObject("Chilkat.Rest")
nBAutoReconnect := 1
nSuccess := oRest:Connect("api.sandbox.paypal.com", 443, 1, nBAutoReconnect)
IF (nSuccess != 1)
    ? oRest:LastErrorText
    oJsonToken:destroy()
    oSbAuth:destroy()
    oRest:destroy()
    RETURN
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 a path using an invoice ID.
oSbPath := CreateObject("Chilkat.StringBuilder")
oSbPath:Append("/v1/invoicing/invoices/invoice_id/qr-code")
nNumReplacements := oSbPath:Replace("invoice_id", "INV2-ZG2H-HKAW-PMWU-N6ZR")

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

//  Send the GET request and get the PNG image data as base64.
//  A successful JSON response looks like this:
//  {"image":"iVBORw0KGgoAA....AASUVORK5CYII="}
oSbJsonResponse := CreateObject("Chilkat.StringBuilder")
nSuccess := oRest:FullRequestNoBodySb("GET", oSbPath:GetAsString(), oSbJsonResponse)
IF (nSuccess != 1)
    ? oRest:LastErrorText
    oJsonToken:destroy()
    oSbAuth:destroy()
    oRest:destroy()
    oSbPath:destroy()
    oSbJsonResponse:destroy()
    RETURN
ENDIF

oJson := CreateObject("Chilkat.JsonObject")
oJson:EmitCompact := 0
oJson:LoadSb(oSbJsonResponse)

? "Response Status Code = " + Str(oRest:ResponseStatusCode)

//  Did we get a 200 success response?
IF (oRest:ResponseStatusCode != 200)
    ? oJson:Emit()
    ? "Failed."
    oJsonToken:destroy()
    oSbAuth:destroy()
    oRest:destroy()
    oSbPath:destroy()
    oSbJsonResponse:destroy()
    oJson:destroy()
    RETURN
ENDIF

//  If the 200 response is received, the response body contains the PNG data.
//  Save the PNG to a file.
oPngData := CreateObject("Chilkat.BinData")
oPngData:AppendEncoded(oJson:StringOf("image"), "base64")
nSuccess := oPngData:WriteFile("qa_output/paypal_qr_code.png")
IF (nSuccess == 0)
    ? "Failed to save PNG file."
    oJsonToken:destroy()
    oSbAuth:destroy()
    oRest:destroy()
    oSbPath:destroy()
    oSbJsonResponse:destroy()
    oJson:destroy()
    oPngData:destroy()
    RETURN
ENDIF

? "Success."

oJsonToken:destroy()
oSbAuth:destroy()
oRest:destroy()
oSbPath:destroy()
oSbJsonResponse:destroy()
oJson:destroy()
oPngData:destroy()