(Visual FoxPro) QuickBooks - Automatically Refresh Access Token with No User Interaction

Demonstrates how to automaticaly refresh an expired access token and retry the request after a 401 authorization error.

Note: This example requires Chilkat v11.0.0 or greater.

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

LOCAL lnSuccess
LOCAL loJsonToken
LOCAL loRest
LOCAL lnBAutoReconnect
LOCAL loSbAuth
LOCAL lcResponseBody
LOCAL loOauth2
LOCAL loSbJson
LOCAL loJson
LOCAL loDtime
LOCAL lnBLocalTime
LOCAL loDt

lnSuccess = 0

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

* Get our previously obtained OAuth2 access token, which should contain JSON like this:
* {
*   "expires_in": 3600,
*   "x_refresh_token_expires_in": 8726400,
*   "refresh_token": "L011546037639r ... 3vR2DrbOmg0Sdagw",
*   "access_token": "eyJlbmMiOiJBMTI4Q0 ... oETJEMbeggg",
*   "token_type": "bearer"
* }

loJsonToken = CreateObject('Chilkat.JsonObject')
lnSuccess = loJsonToken.LoadFile("qa_data/tokens/qb-access-token.json")

loRest = CreateObject('Chilkat.Rest')

* Connect using TLS.
* A single REST object, once connected, can be used for many Quickbooks 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("sandbox-quickbooks.api.intuit.com",443,1,lnBAutoReconnect)
IF (lnSuccess = 0) THEN
    ? loRest.LastErrorText
    RELEASE loJsonToken
    RELEASE loRest
    CANCEL
ENDIF

loSbAuth = CreateObject('Chilkat.StringBuilder')
loSbAuth.Append("Bearer ")
loSbAuth.Append(loJsonToken.StringOf("access_token"))
loRest.Authorization = loSbAuth.GetAsString()

loRest.AddHeader("Accept","application/json")
loRest.AllowHeaderFolding = 0

* The company ID is 123146096291789
* The employee ID is 58
lcResponseBody = loRest.FullRequestNoBody("GET","/v3/company/123146096291789/employee/58?minorversion=45")
IF (loRest.LastMethodSuccess = 0) THEN
    ? loRest.LastErrorText
    RELEASE loJsonToken
    RELEASE loRest
    RELEASE loSbAuth
    CANCEL
ENDIF

* If we get a 401 authorization error, then it's likely because the access token expired.
* We can automatically refresh it without interaction from the user.
IF (loRest.ResponseStatusCode = 401) THEN

    loOauth2 = CreateObject('Chilkat.OAuth2')

    loOauth2.TokenEndpoint = "https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer"

    * Replace these with actual values.
    loOauth2.ClientId = "QUICKBOOKS-CLIENT-ID"
    loOauth2.ClientSecret = "QUICKBOOKS-CLIENT-SECRET"

    * Get the "refresh_token"
    loOauth2.RefreshToken = loJsonToken.StringOf("refresh_token")

    * Send the HTTP POST to refresh the access token..
    lnSuccess = loOauth2.RefreshAccessToken()
    IF (lnSuccess = 0) THEN
        ? loOauth2.LastErrorText
        RELEASE loJsonToken
        RELEASE loRest
        RELEASE loSbAuth
        RELEASE loOauth2
        CANCEL
    ENDIF

    ? "New access token: " + loOauth2.AccessToken

    * Update the JSON with the new tokens.
    loJsonToken.UpdateString("access_token",loOauth2.AccessToken)

    * Save the new JSON access token response to a file.
    * The access + refresh tokens contained in this JSON will be needed for the next refresh.
    loSbJson = CreateObject('Chilkat.StringBuilder')
    loJsonToken.EmitCompact = 0
    loJsonToken.EmitSb(loSbJson)
    loSbJson.WriteFile("qa_data/tokens/qb-access-token.json","utf-8",0)

    ? "OAuth2 token refreshed!"
    ? "New Access Token = " + loOauth2.AccessToken

    loSbAuth.Clear()
    loSbAuth.Append("Bearer ")
    loSbAuth.Append(loOauth2.AccessToken)
    loRest.Authorization = loSbAuth.GetAsString()

    * Now retry the request with the refreshed access token...
    lcResponseBody = loRest.FullRequestNoBody("GET","/v3/company/123146096291789/employee/58?minorversion=45")
    IF (loRest.LastMethodSuccess = 0) THEN
        ? loRest.LastErrorText
        RELEASE loJsonToken
        RELEASE loRest
        RELEASE loSbAuth
        RELEASE loOauth2
        RELEASE loSbJson
        CANCEL
    ENDIF

ENDIF

* We should expect a 200 response if successful.
IF (loRest.ResponseStatusCode <> 200) THEN
    ? "Request Header: "
    ? loRest.LastRequestHeader
    ? "----"
    ? "Response StatusCode = " + STR(loRest.ResponseStatusCode)
    ? "Response StatusLine: " + loRest.ResponseStatusText
    ? "Response Header:"
    ? loRest.ResponseHeader
    ? lcResponseBody
    RELEASE loJsonToken
    RELEASE loRest
    RELEASE loSbAuth
    RELEASE loOauth2
    RELEASE loSbJson
    CANCEL
ENDIF

* Load the JSON response into a JSON object for parsing.
* A sample JSON response is shown below.
loJson = CreateObject('Chilkat.JsonObject')
loJson.Load(lcResponseBody)

* These will be used for parsing date/time strings..
loDtime = CreateObject('Chilkat.CkDateTime')
lnBLocalTime = 1

* Show the JSON.   
loJson.EmitCompact = 0
? loJson.Emit()

* Get some information from the JSON..
? "Name: " + loJson.StringOf("Employee.DisplayName")
? "Id: " + loJson.StringOf("Employee.Id")
? "City: " + loJson.StringOf("Employee.PrimaryAddr.City")
? "PostalCode: " + loJson.StringOf("Employee.PrimaryAddr.PostalCode")

* Load the CreateTime into a CkDateTime...
loDtime.SetFromTimestamp(loJson.StringOf("Employee.MetaData.CreateTime"))
loDt = CreateObject('Chilkat.DtObj')
loDtime.ToDtObj(lnBLocalTime,loDt)

? STR(loDt.Month) + "/" + STR(loDt.Day) + "/" + STR(loDt.Year) + "  " + STR(loDt.Hour) + ":" + STR(loDt.Minute)

? "Success."

* Use this online tool to generate parsing code from sample JSON: 
* Generate Parsing Code from JSON

* ------------------------------------------------------
* The JSON response looks like this:

* {
*   "Employee": {
*     "SSN": "XXX-XX-XXXX",
*     "PrimaryAddr": {
*       "Id": "116",
*       "Line1": "45 N. Elm Street",
*       "City": "Middlefield",
*       "CountrySubDivisionCode": "CA",
*       "PostalCode": "93242"
*     },
*     "BillableTime": false,
*     "domain": "QBO",
*     "sparse": false,
*     "Id": "98",
*     "SyncToken": "0",
*     "MetaData": {
*       "CreateTime": "2015-07-24T09:34:35-07:00",
*       "LastUpdatedTime": "2015-07-24T09:34:35-07:00"
*     },
*     "GivenName": "Bill",
*     "FamilyName": "Miller",
*     "DisplayName": "Bill Miller",
*     "PrintOnCheckName": "Bill Miller",
*     "Active": true,
*     "PrimaryPhone": {
*       "FreeFormNumber": "234-525-1234"
*     }
*   },
*   "time": "2015-07-24T09:35:54.805-07:00"
* 

RELEASE loJsonToken
RELEASE loRest
RELEASE loSbAuth
RELEASE loOauth2
RELEASE loSbJson
RELEASE loJson
RELEASE loDtime
RELEASE loDt