transformResult

Type declaration

export type TransformResultOptions = {
  dispatch?: DispatchOption
}
/**
 * Make changes to items in `context.result`. Very flexible.
 *
 * @see https://utils.feathersjs.com/hooks/transform-result.html
 */
export declare const transformResult: <
  T = Record<string, any>,
  H extends HookContext = HookContext,
>(
  transformer: TransformerFn<T, H>,
  options?: TransformResultOptions,
) => (context: H, next?: NextFunction) => Promise<H>

Argument	Type	Description
transformer	TransformerFn<T, H>
options	TransformResultOptions

type	methods	multi
before, after, around	find, get, create, update, patch, remove	yes

transformResult is a hook that allows you to transform the result data after it has been retrieved from the database. This can be useful for modifying the structure of the result, applying transformations to the fields, or adding additional information to the result.

Async Transformations

This hook supports asynchronous transformations. You can return a promise from the hook to perform asynchronous operations before the result is processed. However, be cautious as this can lead to performance issues if the transformations are slow or if there are many records to process. When you need to call another service or perform a database query, it's usually better to create your own hook that fetches the necessary data before transformResult is called.

You can use transformResult like this:

import { transformResult } from "feathers-utils/hooks";
import { getResultIsArray } from "feathers-utils/utils";

const myHook = () => async (context) => {
  const { result } = getResultIsArray(context);

  await transformResult((item) => {
    // or whatever transformation you need
    item.userEmail = users.find((u) => u.id === item.userId)?.email;
    return item;
  })(context);
};

Transformers

'feathers-utils' provides a set of transformers that can be used with this hook. These transformers can be used to trim strings, convert dates, or omit fields from the result.

lowercase

Transforms the specified fields of an item to lowercase.

omit

Omit the specified fields from an item.

parseDate

pick

Picks the specified fields from an item.

setNow

Sets the specified fields of an item to the current date and time.

trim

Trims the specified fields of an item.