(Visual FoxPro) RSAP Union API - Get OAuth2 Access Token

Demonstrates how to get an OAuth2 access token for the RSAP Union API. Note: This uses the client credentials flow, which does NOT require an interactive engagement using a browser.

For more information, see https://app.swaggerhub.com/apis-docs/pderas/RSAP/2.0.1#/Authentication/getOauthToken

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loHttp
LOCAL lnSuccess
LOCAL loJson
LOCAL loCert
LOCAL loPrivKey
LOCAL loResp
LOCAL loSbResponseBody
LOCAL loJResp
LOCAL lnRespStatusCode

* This example assumes the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Http')
loHttp = CreateObject('Chilkat.Http')

* The following JSON is sent in the request body.

* {
*   "grant_type": "client_credentials",
*   "client_id": 1234,
*   "client_secret": "23456abcde"
* }

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.UpdateString("grant_type","client_credentials")
loJson.UpdateInt("client_id",1234)
loJson.UpdateString("client_secret","23456abcde")

loHttp.SetRequestHeader("Content-type","application/json")

* Add the client certificate TLS authentication.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Cert')
loCert = CreateObject('Chilkat.Cert')
lnSuccess = loCert.LoadFromFile("qa_data/certs_and_keys/union_client_certificate.crt")
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    RELEASE loCert
    CANCEL
ENDIF

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.PrivateKey')
loPrivKey = CreateObject('Chilkat.PrivateKey')
lnSuccess = loPrivKey.LoadAnyFormatFile("qa_data/certs_and_keys/union_client_certificate.nopass.key","")
IF (lnSuccess = 0) THEN
    ? loPrivKey.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    RELEASE loCert
    RELEASE loPrivKey
    CANCEL
ENDIF

* Associate the private key with the cert.
* This will fail if the private key is not actually the correct one that corresponds to the public key stored within the cert.
lnSuccess = loCert.SetPrivateKey(loPrivKey)
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    RELEASE loCert
    RELEASE loPrivKey
    CANCEL
ENDIF

* Tell HTTP to use the cert for client TLS certificate authentication.
lnSuccess = loHttp.SetSslClientCert(loCert)
IF (lnSuccess = 0) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    RELEASE loCert
    RELEASE loPrivKey
    CANCEL
ENDIF

loResp = loHttp.PostJson3("https://api-test.rsap.ca/oauth/token","application/json",loJson)
IF (loHttp.LastMethodSuccess = 0) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    RELEASE loCert
    RELEASE loPrivKey
    CANCEL
ENDIF

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbResponseBody = CreateObject('Chilkat.StringBuilder')
loResp.GetBodySb(loSbResponseBody)
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJResp = CreateObject('Chilkat.JsonObject')
loJResp.LoadSb(loSbResponseBody)
loJResp.EmitCompact = 0

? "Response Body:"
? loJResp.Emit()

lnRespStatusCode = loResp.StatusCode
? "Response Status Code = " + STR(lnRespStatusCode)
IF (lnRespStatusCode >= 400) THEN
    ? "Response Header:"
    ? loResp.Header
    ? "Failed."
    RELEASE loResp
    RELEASE loHttp
    RELEASE loJson
    RELEASE loCert
    RELEASE loPrivKey
    RELEASE loSbResponseBody
    RELEASE loJResp
    CANCEL
ENDIF

RELEASE loResp

* Sample JSON response:
* (Sample code for parsing the JSON response is shown below)

* {
*   "token_type": "Bearer",
*   "expires_in": 3600,
*   "access_token": "eyJ0eXAi...LnE"
* }

* This token expires in 1 hour.  Your application could re-use the same token for up to an hour,
* or it can simply get a new access token before each request (if you're not doing too many requests).
lnSuccess = loJResp.WriteFile("qa_data/tokens/rsapToken.json")

RELEASE loHttp
RELEASE loJson
RELEASE loCert
RELEASE loPrivKey
RELEASE loSbResponseBody
RELEASE loJResp