Visual FoxPro

Xero 2 Legged OAuth for Private Application

This example demonstrates the REST object for 2-legged OAuth for a private application.

An application can setup OAuth1 for a given instance of the Chilkat REST object, and then use the instance for many REST API calls. This example demonstrates the OAuth1 setup and initial connection. This code would typically be placed in a subroutine/function to "initalize" the REST object before beginning to use it for REST HTTP requests.

Note: Xero private applications use 2 legged OAuth and bypass the user authorization workflow in the standard OAuth process. Private applications are linked to a single Xero organisation which is chosen when you register your application. In summary: 2-legged OAuth1 is for applications that access the data that they themselves own.

Visual FoxPro

LOCAL lnSuccess
LOCAL loRest
LOCAL lcConsumerKey
LOCAL lcConsumerSecret
LOCAL loPfx
LOCAL loPrivKeyFromPfx
LOCAL loPrivKeyFromPem
LOCAL loOauth1
LOCAL lnBAutoReconnect

lnSuccess = 0

* This sample code would typically be placed in a subroutine or function
* where the rest object is passed by reference.
* It does the OAuth1 setup and makes the initial connection.
loRest = CreateObject('Chilkat.Rest')

lcConsumerKey = "XERO_PRIVATE_APP_KEY"
lcConsumerSecret = "XERO_PRIVATE_APP_SECRET"

* Let's get our private key from our PFX (password protected), or the PEM (unprotected).
* You can decide which to use.  Either is OK, although I would recommend keeping your
* private keys in a PFX and not in an unprotected PEM.
loPfx = CreateObject('Chilkat.Pfx')
lnSuccess = loPfx.LoadPfxFile("qa_data/certs/xero_private_app/public_privatekey.pfx","PFX_PASSWORD")
IF (lnSuccess = 0) THEN
    ? loPfx.LastErrorText
    RELEASE loRest
    RELEASE loPfx
    CANCEL
ENDIF

loPrivKeyFromPfx = CreateObject('Chilkat.PrivateKey')
lnSuccess = loPfx.PrivateKeyAt(0,loPrivKeyFromPfx)
IF (lnSuccess = 0) THEN
    ? loPfx.LastErrorText
    RELEASE loRest
    RELEASE loPfx
    RELEASE loPrivKeyFromPfx
    CANCEL
ENDIF

* Or we can load from a PEM..
loPrivKeyFromPem = CreateObject('Chilkat.PrivateKey')
lnSuccess = loPrivKeyFromPem.LoadPemFile("qa_data/certs/xero_private_app/privatekey.pem")
IF (lnSuccess = 0) THEN
    ? loPrivKeyFromPem.LastErrorText
    RELEASE loRest
    RELEASE loPfx
    RELEASE loPrivKeyFromPfx
    RELEASE loPrivKeyFromPem
    CANCEL
ENDIF

* Note: There are many other means for loading a private key, including
* from other formats and directly from memory (i.e. not file-based).

loOauth1 = CreateObject('Chilkat.OAuth1')
loOauth1.ConsumerKey = lcConsumerKey
loOauth1.ConsumerSecret = lcConsumerSecret
loOauth1.Token = lcConsumerKey
loOauth1.TokenSecret = lcConsumerSecret
loOauth1.SignatureMethod = "RSA-SHA1"
loOauth1.SetRsaKey(loPrivKeyFromPfx)

* Make the initial connection.
* A single REST object, once connected, can be used for many Xero 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.
lnBAutoReconnect = 1
lnSuccess = loRest.Connect("api.xero.com",443,1,lnBAutoReconnect)
IF (lnSuccess = 0) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    RELEASE loPfx
    RELEASE loPrivKeyFromPfx
    RELEASE loPrivKeyFromPem
    RELEASE loOauth1
    CANCEL
ENDIF

* Finally, install the OAuth1 authenticator.
* (It make no difference whether this happens before or after the
* connection is established.)
loRest.SetAuthOAuth1(loOauth1,0)

? "OK, the Xero OAuth1 is initialized and the REST object is ready to make REST API calls.."

RELEASE loRest
RELEASE loPfx
RELEASE loPrivKeyFromPfx
RELEASE loPrivKeyFromPem
RELEASE loOauth1