DataFlex

Refresh Expiring OAuth2 Access Token for Azure Registered App

See more OAuth2 Examples

Shows how to renew an Azure App's access token using the refresh token when it's near expiration. DataFlex

Use ChilkatAx-win32.pkg

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

    Move False To iSuccess

    // 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