Function

Configures how unique identifier lid strings are generated by @ember-data/store.

This configuration MUST occur prior to the store instance being created.

Takes a method which can expect to receive various data as its first argument and the name of a bucket as its second argument.

Currently there are two buckets, 'record' and 'document'.

Resource (Record) Identity

If the bucket is record the method must return a unique (to at-least the given bucket) string identifier for the given data as a string to be used as the lid of an Identifier token.

This method will only be called by either getOrCreateRecordIdentifier or createIdentifierForNewRecord when an identifier for the supplied data is not already known via lid or type + id combo and one needs to be generated or retrieved from a proprietary cache.

data will be the same data argument provided to getOrCreateRecordIdentifier and in the createIdentifierForNewRecord case will be an object with only type as a key.

import { setIdentifierGenerationMethod } from '@ember-data/store';

export function initialize(applicationInstance) {
  // note how `count` here is now scoped to the application instance
  // for our generation method by being inside the closure provided
  // by the initialize function
  let count = 0;

  setIdentifierGenerationMethod((resource, bucket) => {
    return resource.lid || `my-key-${count++}`;
  });
}

export default {
  name: 'configure-ember-data-identifiers',
  initialize
};

Document Identity

If the bucket is document the method will receive the associated immutable request passed to store.request as its first argument and should return a unique string for the given request if the document should be cached, and null if it should not be cached.

Note, the request result will still be passed to the cache via Cache.put, but caches should take this as a signal that the document should not itself be cached, while its contents may still be used to update other cache state.

The presence of cacheOptions.key on the request will take precedence for the document cache key, and this method will not be called if it is present.

The default method implementation for this bucket is to return null for all requests whose method is not GET, and to return the url for those where it is.

This means that queries via POST MUST provide cacheOptions.key or implement this hook.

⚠️ Caution: Requests that do not have a method assigned are assumed to be GET