Hello Everyone I have a token refresh system which requires me to read the response everytime, and b...

# ktor

[Prateek Kumar]

Hello Everyone
I have a token refresh system which requires me to read the response everytime, and based on that i need to decide if i need to refetch the token or proceed with the request.

I have come up with a Plugin something like:-

val AuthPlugin = createClientPlugin("AuthPlugin", ::AuthPluginConfig) {
    on(Send) { request ->
        val originalCall = proceed(request)
        
        val code = originalCall.response.bodyAsText().decodeResponseCode()
        
        return@on if (code == TOKEN_EXPIRE) {
            val tokenRefreshRequest = HttpRequestBuilder() //Create Token Refresh request
            val newToken = proceed(tokenRefreshRequest).parseToken()
            request.headers[DR_TOKEN] = newToken
            proceed(request)
        } else {
            originalCall
        }
    }
}

But the problem is , ByteReadChannel can only be read once, once i read the response , further layer fails.
Am i going in the right direction or is there any way i can make a copy of ByteReadChannel?

[Aleksei Tirman [JB]]

Have you tried implementing the AuthProvider and use the Auth plugin (https://ktor.io/docs/client-auth.html)?

[Prateek Kumar]

I did have a look and from what i saw it will work with 401 status code , But the system i am working with gives 200 , and there is a custom status code which comes alongwith response, using which i need to figure out if i need to reauth or not

[Aleksei Tirman [JB]]

To double receive the response you can use the SaveBodyPlugin which, unfortunately, is only available in the 3.0.0-beta-1 release and 3.0.0 EAP releases.

[Prateek Kumar]

I did check it , i don’t think that will help
My requirement is more like
If the response has auth failure custom code then call another API to get new token and then again make the original request with the newely received token.

It is more like a chain request.

[Prateek Kumar]

If only i could make a copy of the body and use it for my purpose in above shown plugin which i have created,it would have worked.

[Aleksei Tirman [JB]]

If the request body isn't big you can save the request body to a byte array before executing the first request and then later use it for both requests.