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

LOCAL loJsonToken
LOCAL loSbAuth
LOCAL loRest
LOCAL lnBAutoReconnect
LOCAL lnSuccess
LOCAL loSbPath
LOCAL lnNumReplacements
LOCAL loSbJsonResponse
LOCAL loJson
LOCAL loPngData

* 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)
* 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 a path using an 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/qr-code")
lnNumReplacements = loSbPath.Replace("invoice_id","INV2-ZG2H-HKAW-PMWU-N6ZR")

loRest.AddHeader("Authorization",loSbAuth.GetAsString())
* A 500x500 image results in a PNG file of approx. 4K bytes in size.
loRest.AddQueryParam("width","500")
loRest.AddQueryParam("height","500")
loRest.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="}
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbJsonResponse = CreateObject('Chilkat.StringBuilder')
lnSuccess = loRest.FullRequestNoBodySb("GET",loSbPath.GetAsString(),loSbJsonResponse)
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loJsonToken
    RELEASE loSbAuth
    RELEASE loRest
    RELEASE loSbPath
    RELEASE loSbJsonResponse
    CANCEL
ENDIF

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.EmitCompact = 0
loJson.LoadSb(loSbJsonResponse)

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

* Did we get a 200 success response?
IF (loRest.ResponseStatusCode <> 200) THEN
    ? loJson.Emit()
    ? "Failed."
    RELEASE loJsonToken
    RELEASE loSbAuth
    RELEASE loRest
    RELEASE loSbPath
    RELEASE loSbJsonResponse
    RELEASE loJson
    CANCEL
ENDIF

* If the 200 response is received, the response body contains the PNG data.
* Save the PNG to a file.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loPngData = CreateObject('Chilkat.BinData')
loPngData.AppendEncoded(loJson.StringOf("image"),"base64")
lnSuccess = loPngData.WriteFile("qa_output/paypal_qr_code.png")
IF (lnSuccess = 0) THEN
    ? "Failed to save PNG file."
    RELEASE loJsonToken
    RELEASE loSbAuth
    RELEASE loRest
    RELEASE loSbPath
    RELEASE loSbJsonResponse
    RELEASE loJson
    RELEASE loPngData
    CANCEL
ENDIF

? "Success."

RELEASE loJsonToken
RELEASE loSbAuth
RELEASE loRest
RELEASE loSbPath
RELEASE loSbJsonResponse
RELEASE loJson
RELEASE loPngData