(PureBasic) 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 PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkBinData.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkRest.pb"

Procedure ChilkatExample()

    ; 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)
    jsonToken.i = CkJsonObject::ckCreate()
    If jsonToken.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoadFile(jsonToken,"qa_data/tokens/paypal.json")

    ; Build the Authorization request header field value.
    sbAuth.i = CkStringBuilder::ckCreate()
    If sbAuth.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; token_type should be "Bearer"
    CkStringBuilder::ckAppend(sbAuth,CkJsonObject::ckStringOf(jsonToken,"token_type"))
    CkStringBuilder::ckAppend(sbAuth," ")
    CkStringBuilder::ckAppend(sbAuth,CkJsonObject::ckStringOf(jsonToken,"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.
    rest.i = CkRest::ckCreate()
    If rest.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    bAutoReconnect.i = 1
    success.i = CkRest::ckConnect(rest,"api.sandbox.paypal.com",443,1,bAutoReconnect)
    If success <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkJsonObject::ckDispose(jsonToken)
        CkStringBuilder::ckDispose(sbAuth)
        CkRest::ckDispose(rest)
        ProcedureReturn
    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.
    sbPath.i = CkStringBuilder::ckCreate()
    If sbPath.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkStringBuilder::ckAppend(sbPath,"/v1/invoicing/invoices/invoice_id/qr-code")
    numReplacements.i = CkStringBuilder::ckReplace(sbPath,"invoice_id","INV2-ZG2H-HKAW-PMWU-N6ZR")

    CkRest::ckAddHeader(rest,"Authorization",CkStringBuilder::ckGetAsString(sbAuth))
    ; A 500x500 image results in a PNG file of approx. 4K bytes in size.
    CkRest::ckAddQueryParam(rest,"width","500")
    CkRest::ckAddQueryParam(rest,"height","500")
    CkRest::ckAddQueryParam(rest,"action","pay")

    ; Send the GET request and get the PNG image data as base64.
    ; A successful JSON response looks like this:
    ; {"image":"iVBORw0KGgoAA....AASUVORK5CYII="}
    sbJsonResponse.i = CkStringBuilder::ckCreate()
    If sbJsonResponse.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkRest::ckFullRequestNoBodySb(rest,"GET",CkStringBuilder::ckGetAsString(sbPath),sbJsonResponse)
    If success <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkJsonObject::ckDispose(jsonToken)
        CkStringBuilder::ckDispose(sbAuth)
        CkRest::ckDispose(rest)
        CkStringBuilder::ckDispose(sbPath)
        CkStringBuilder::ckDispose(sbJsonResponse)
        ProcedureReturn
    EndIf

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::setCkEmitCompact(json, 0)
    CkJsonObject::ckLoadSb(json,sbJsonResponse)

    Debug "Response Status Code = " + Str(CkRest::ckResponseStatusCode(rest))

    ; Did we get a 200 success response?
    If CkRest::ckResponseStatusCode(rest) <> 200
        Debug CkJsonObject::ckEmit(json)
        Debug "Failed."
        CkJsonObject::ckDispose(jsonToken)
        CkStringBuilder::ckDispose(sbAuth)
        CkRest::ckDispose(rest)
        CkStringBuilder::ckDispose(sbPath)
        CkStringBuilder::ckDispose(sbJsonResponse)
        CkJsonObject::ckDispose(json)
        ProcedureReturn
    EndIf

    ; If the 200 response is received, the response body contains the PNG data.
    ; Save the PNG to a file.
    pngData.i = CkBinData::ckCreate()
    If pngData.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkBinData::ckAppendEncoded(pngData,CkJsonObject::ckStringOf(json,"image"),"base64")
    success = CkBinData::ckWriteFile(pngData,"qa_output/paypal_qr_code.png")
    If success = 0
        Debug "Failed to save PNG file."
        CkJsonObject::ckDispose(jsonToken)
        CkStringBuilder::ckDispose(sbAuth)
        CkRest::ckDispose(rest)
        CkStringBuilder::ckDispose(sbPath)
        CkStringBuilder::ckDispose(sbJsonResponse)
        CkJsonObject::ckDispose(json)
        CkBinData::ckDispose(pngData)
        ProcedureReturn
    EndIf

    Debug "Success."


    CkJsonObject::ckDispose(jsonToken)
    CkStringBuilder::ckDispose(sbAuth)
    CkRest::ckDispose(rest)
    CkStringBuilder::ckDispose(sbPath)
    CkStringBuilder::ckDispose(sbJsonResponse)
    CkJsonObject::ckDispose(json)
    CkBinData::ckDispose(pngData)


    ProcedureReturn
EndProcedure