fix url not updating state

[FlorianCassayre]

• fixes url history not updating the internal state
• closes inveniosoftware/react-invenio-app-ils#274

Tested on zenodo demo and on ILS. Also tested on CDS videos demo which has disabled support for url handling.

It may not be the best way to do it, but it works. I'm preventing the url from being updated twice: this is a workaround (I hope temporary) because the url is replaced twice, and even though the state is equivalent in both cases the order of the attributes is not.

Open to suggestions.

[FlorianCassayre]

Because of this change, nothing prevents the user from making concurrent requests using the history (ie. clicking on the "back" button several times). Therefore we need to handle these cases to avoid race conditions: see 15457b6. I used the following widespread pattern for requests:

• any request that is made triggers a loading state
• a completion (regardless if it is successful or not) is accepted only if the corresponding request is the latest that was made, otherwise it is ignored

Imagine that the user previously visited B, A and C in this order. Now the user clicks on "back" twice. The following scenarios can occur:

• (a)
  1. request A => loading
  2. A completes => show A
  3. request B => loading
  4. B completes => show B
• (b)
  1. request A => loading
  2. request B => loading
  3. A completes => ignored, thus still loading
  4. B completes => show B
• (c)
  1. request A => loading
  2. request B => loading
  3. B completes => show B
  4. A completes => ignored, thus still show B

[FlorianCassayre]

PR was revised:

• the action SET_QUERY_STATE was updating the state instead of setting (= replacing) it, I fixed it and removed the newly created action
• the parameters of the url are now sorted lexicographically by their key, except for q which is meant to appear first
• removed the temporary parameter replaceUrl since now the replaced url has no change

[FlorianCassayre]

Changes:

    case SET_QUERY_STATE:
      return {
        ...state,
        ...INITIAL_QUERY_STATE,
-       ...action.payload,
+       ...updateQueryState(INITIAL_QUERY_STATE, action.payload, INITIAL_QUERY_STATE_KEYS),
      };

INITIAL_QUERY_STATE is required for the filters to be correctly reset.