---
url: >-
  https://canary.warp-drive.io/api/@warp-drive/core/functions/setIdentifierGenerationMethod.md
description: >-
  Overrides how the store generates `lid` cache keys for resources and
  documents; must be set before the store is created.
---

#  setIdentifierGenerationMethod()

```ts
function setIdentifierGenerationMethod(method: GenerationMethod | null): void;
```

Defined in: [warp-drive-packages/core/src/store/-private/managers/cache-key-manager.ts:264](https://github.com/warp-drive-data/warp-drive/blob/2c7e65270a86c54924fdb4e96225b70c42e46d91/warp-drive-packages/core/src/store/-private/managers/cache-key-manager.ts#L264)

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.

```ts
import { setIdentifierGenerationMethod } from '@warp-drive/core';

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`

## Parameters

### method

`GenerationMethod` | `null`

## Returns

`void`