(DataFlex) Refresh Expiring OAuth2 Access Token for Azure Registered App

See more OAuth2 Examples

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

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoJson
    Boolean iSuccess
    Handle hoDtExpire
    Handle hoOauth2
    Handle hoFac
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    // We previously obtained an access token and saved the JSON to a file using this example:
    // Get OAuth2 Access Token for Azure Registered App

    // This example will examine the JSON and expiration date, and if near expiration will
    // refresh the access token.

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get ComLoadFile Of hoJson "qa_data/tokens/_myAzureApp.json" To iSuccess
    If (iSuccess <> True) Begin
        Showln "Failed to load the access token."
        Procedure_Return
    End

    // The contents of the JSON look like this:
    // {
    //   "token_type": "Bearer",
    //   "scope": "User.Read Mail.ReadWrite Mail.Send",
    //   "expires_in": 3600,
    //   "ext_expires_in": 0,
    //   "access_token": "EwBAA8l6B...",
    //   "refresh_token": "MCRMdbe6Cd...",
    //   "id_token": "eyJ0eXAiOiJ...",
    //   "expires_on": "1494112119"
    // }

    // The "expires_on" value is a Unix time.
    Get Create (RefClass(cComCkDateTime)) To hoDtExpire
    If (Not(IsComObjectCreated(hoDtExpire))) Begin
        Send CreateComObject of hoDtExpire
    End
    Get ComIntOf Of hoJson "expires_on" To iTemp1
    Get ComSetFromUnixTime Of hoDtExpire False iTemp1 To iSuccess

    // If this date/time expires within 10 minutes of the current system time, refresh the token.
    Get ComExpiresWithin Of hoDtExpire 10 "minutes" To bTemp1
    If (bTemp1 <> True) Begin
        Showln "No need to refresh, the access token won't expire within the next 10 minutes."
        Procedure_Return
    End

    // OK, we need to refresh the access token..
    Get Create (RefClass(cComChilkatOAuth2)) To hoOauth2
    If (Not(IsComObjectCreated(hoOauth2))) Begin
        Send CreateComObject of hoOauth2
    End

    // Note: The endpoint depends on the Azure App Registration.
    // See How to Choose the Correct Endpoints for your Azure App Registration
    Set ComTokenEndpoint Of hoOauth2 To "https://login.microsoftonline.com/common/oauth2/v2.0/token"

    // Use your client ID.
    Set ComClientId Of hoOauth2 To "CLIENT_ID"

    // Get the existing refresh token.
    Get ComStringOf Of hoJson "refresh_token" To sTemp1
    Set ComRefreshToken Of hoOauth2 To sTemp1

    // Send the HTTP POST to refresh the access token.
    Get ComRefreshAccessToken Of hoOauth2 To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoOauth2 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "OAuth2 authorization granted!"
    Get ComAccessToken Of hoOauth2 To sTemp1
    Showln "Access Token = " sTemp1

    // Get the full JSON response:
    Get ComAccessTokenResponse Of hoOauth2 To sTemp1
    Get ComLoad Of hoJson sTemp1 To iSuccess
    Set ComEmitCompact Of hoJson To False

    // If an "expires_on" member does not exist, then add the JSON member by
    // getting the current system date/time and adding the "expires_in" seconds.
    // This way we'll know when the token expires.
    Get ComHasMember Of hoJson "expires_on" To bTemp1
    If (bTemp1 <> True) Begin
        Get ComSetFromCurrentSystemTime Of hoDtExpire To iSuccess
        Get ComIntOf Of hoJson "expires_in" To iTemp1
        Get ComAddSeconds Of hoDtExpire iTemp1 To iSuccess
        Get ComGetAsUnixTimeStr Of hoDtExpire False To sTemp1
        Get ComAppendString Of hoJson "expires_on" sTemp1 To iSuccess
    End

    Get ComEmit Of hoJson To sTemp1
    Showln sTemp1

    // Save the new access token JSON to a file for future requests.
    Get Create (RefClass(cComCkFileAccess)) To hoFac
    If (Not(IsComObjectCreated(hoFac))) Begin
        Send CreateComObject of hoFac
    End
    Get ComEmit Of hoJson To sTemp1
    Get ComWriteEntireTextFile Of hoFac "qa_data/tokens/_myAzureApp.json" sTemp1 "utf-8" False To iSuccess


End_Procedure