Client: Support Service Middleware / Generic Service about feathers-rest HOT 5 CLOSED

I wrote the hook updates up in this blog post and it will also be in the Auk docs.

from feathers-rest.

I think this can be done at the service and hook level already. The following snippet should cache outgoing requests and return the cached request if the same request is made again while the current one is still going:

const cache = {};

app.hooks({
  before(hook) {
    const key = JSON.stringify([ hook.id, hook.params, hook.data ]);
    // Noop for caching
    hook.updateCache = function() {};

    if(cache[key]) {
      // Use the cache promise to set hook.result
      return cache[key].then(result => {
        hook.result = result;
        return hook;
      });
    } else {
      // Set the `hook.updateCache` method to resolve the promise we are putting in the cache
      cache[key] = new Promise((resolve, reject) => {
        hook.updateCache = function() {
          delete cache[key];

          if(hook.error) {
            reject(hook.error);
          } else {
            resolve(hook.result)
          }
        }
      });
    }
  },

  after(hook) {
    hook.updateCache();
  },

  error(hook) {
    hook.updateCache();
  }
});

There is probably other optimizations (e.g. a small timeout to gather more requests). Eventually we'd probably want to implement a more generalized caching plugin (that works on the server and client) and also update feathers-batch (which is somewhat related).

from feathers-rest.

Ah great, yeah that looks like it'll do the trick. I'll use that in future - thanks! I'm happy with that as a solution, and I'll keep an eye on feathers-hooks-common.

from feathers-rest.

@daffl it would be great to add that snippet to the client documentation.
The error hook was particularly helpful for me as I was trying to do this using all kinds of things like trying to extend the services with methods that would catch errors on the request calls and then re-throw again ... it wasn't until I came across this issue that I realized you could set app level hooks 👍

from feathers-rest.

@daffl I was not aware of that so thanks for the references. The error hook at the app level is definitely super useful both on the client and the server!

from feathers-rest.