Cache invalidate based on headers

[sriteja777]

For RTK Query

Currently the cache key takes only the query args into consideration for deciding validation of cache.
We have an endpoint getPosts and in the headers of this GET request we are sending the JWT token of the user. The response is different based on whether the token is present or not. We use prepareHeaders to set the token in requests instead of sending it as arg in every request.

baseQuery: fetchBaseQuery({
  baseUrl: apiConfig.baseUrl,
  prepareHeaders: (headers, { getState }) => {
    // By default, if we have a token in the store, let's use that for authenticated requests
    const token = (getState() as RootState).user.token
    if (token) {
      headers.set(Constants.AUTH_HEADER, token)
    }  
    return headers
  },

But with current setup the getPosts will not refetch data from server if the token in Header changes. Is there any way / workaround to achieve this?

• One solution is to send the token as query arg, but token needs to be sent every where the posts are required. Is there any way to minimize this?

[phryneas]

Hmm, if you can derive that from the response, you can add some kind of "UNAUTHENTICATED" tag to queries that were not authenticated.
At the moment we do not have meta available in providesTags/invalidatesTag at the moment, but it would probably be consistent with transformResponse to add it to these two functions too. Then you could look in there and look at the actual request & response including headers.

Pull Requests in that direction would be very welcome - at the moment I don't have the time to do a lot on RTK.

[bever1337]

I just submitted a PR to pass meta arg to result description functions. This is my first redux commit, so the changes lean more towards "perfectly serviceable" than "wow, such beautiful code". Please let me know what adjustments I can make.

[phryneas]

The meta argument has been released in https://github.com/reduxjs/redux-toolkit/releases/tag/v1.7.2

This should be possible now.