Xbase++ Requires Chilkat v9.5.0.97+

Refresh OAuth2 Access Token with Optional Params

See more OAuth2 Examples

Demonstrates how to refresh an OAuth2 access token with optional query params included in the HTTP request. Xbase++

LOCAL nSuccess
LOCAL oJsonToken
LOCAL oOauth2
LOCAL oSbJson

nSuccess := 0

//  Here is a sampling of possible optional parameters that might
//  be used by some OAuth2 providers.

//  Optional Parameters
//  
//      "scope":
//          Specifies the scope of the access request. If omitted, the authorization
//          server may issue a token with the same scope as the original token.
//          Example: "scope=read write"
//  
//      "redirect_uri":
//          The redirect URI used in the original authorization request. Some
//          servers may require this for validation.
//          Example: "redirect_uri=https://example.com/callback"
//  
//      "resource":
//          Indicates the target resource or audience for the token. This is used in
//          some implementations (e.g., Microsoft Identity Platform).
//          Example: "resource=https://api.example.com"
//  
//      "audience":
//          Similar to "resource", this specifies the intended audience for the
//          token (used in some OAuth2 implementations like Auth0).
//          Example: "audience=https://api.example.com"
//  
//      "client_assertion" and "client_assertion_type":
//          Used for client authentication using a signed JWT instead of a client
//          secret.
//          Example:client_assertion=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...        
//          client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer
//  
//      "token_type_hint":
//          Provides a hint to the authorization server about the type of token
//          being refreshed. This is rarely used but can be helpful in some cases.
//          Example: "token_type_hint=refresh_token"
//  
//      "assertion":
//          Used in some flows (e.g., SAML bearer assertion flow) to provide an
//          assertion for token issuance.
//          Example: "assertion=PHNhbWxwOl..."
//  
//      "requested_token_use":
//          Specifies how the token will be used (e.g., "on_behalf_of" in the
//          On-Behalf-Of flow used by Microsoft Identity Platform).
//          Example: "requested_token_use=on_behalf_of"
//  

//  --------------------------------------------------------------------------------
//  This example wll refresh the access token and includes the "audience"
//  optional query parameter.
//  
//  

//  Get the access token to be refreshed.
oJsonToken := CreateObject("Chilkat.JsonObject")
nSuccess := oJsonToken:LoadFile("qa_data/tokens/myAccessToken.json")
IF (nSuccess != 1)
    ? "Failed to load hmrc.json"
    oJsonToken:destroy()
    RETURN
ENDIF

oOauth2 := CreateObject("Chilkat.OAuth2")

oOauth2:TokenEndpoint := "https://api.example.com/oauth/token"

//  Replace these with actual values.
oOauth2:ClientId := "CLIENT_ID"
oOauth2:ClientSecret := "CLIENT_SECRET"

//  Add the optional refresh query param.
//  Call AddRefreshQueryParam multiple times to add additional params.
oOauth2:AddRefreshQueryParam("audience", "https://api.example.com")

//  Provide the existing refresh token from the JSON.
oOauth2:RefreshToken := oJsonToken:StringOf("refresh_token")

//  Send the HTTP POST to refresh the access token..
nSuccess := oOauth2:RefreshAccessToken()
IF (nSuccess != 1)
    ? oOauth2:LastErrorText
    oJsonToken:destroy()
    oOauth2:destroy()
    RETURN
ENDIF

//  Load the access token response into the json object 
oJsonToken:Load(oOauth2:AccessTokenResponse)

//  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.
oSbJson := CreateObject("Chilkat.StringBuilder")
oJsonToken:EmitCompact := 0
oJsonToken:EmitSb(oSbJson)
oSbJson:WriteFile("qa_data/tokens/myAccessToken.json", "utf-8", 0)

? "OAuth2 access token refreshed!"
? "New Access Token = " + oOauth2:AccessToken

oJsonToken:destroy()
oOauth2:destroy()
oSbJson:destroy()