Orbit strategy with filter based on whether in cache or not

store-yapp-api-query-blocking.js

import {
  RequestStrategy,
} from '@orbit/coordinator';

export default {
  create() {
    return new RequestStrategy({
      name: 'store-yapp-api-query-blocking',

      source: 'store',
      on: 'beforeQuery',

      target: 'yapp-api',
      action: 'pull',

      blocking: true,

      filter: onlySingleRecordLookupsThatAreNotAlreadyCached,

      catch(e) {
        console.log('error performing yapp-api.pull', e); // eslint-disable-line
        this.source.requestQueue.skip();
        this.target.requestQueue.skip();
        throw e;
      }
    });
  }
};


function onlySingleRecordLookupsThatAreNotAlreadyCached(query) {
  if (query.expression.op !== 'findRecord') {
    return false;
  }
  return !this.source.cache.getRecordSync(query.expression.record);
}