traverse

Category

hooks

Source Code | Documentation

Tags

querydataresult

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Recursively walks and transforms fields in record(s) using neotraverse. The getObject function extracts the target from the context, and transformer is called for every node during traversal --- ideal for deep, structural transformations.

  import { traverse } from 'feathers-utils/hooks';

Example

import { traverse } from 'feathers-utils/hooks'

app.service('users').hooks({
  after: {
    all: [traverse({ getObject: (ctx) => ctx.result, transformer: function () { if (this.key === 'password') this.remove() } })]
  }
})

Options

transformer(transformContext: any) => anyrequired

Called for every node of the traversal, with neotraverse's context as this — so this.key, this.update(value) and this.remove() are what the transformation is written in terms of.

getObject(context: HookContext) => Record<string, any> | Record<string, any>[]required

Picks what is walked out of the hook context, e.g. context.data, context.params.query or context.result. The returned object is traversed in place — context.params.query is deep-cloned first, so walking it leaves the caller's query untouched (other params members are walked as they are).

runAfterbooleandefaultfalse

For around hooks only: run the traversal after next() instead of before. Required when getObject targets context.result, which is only populated once the service method has run. Defaults to false (run before next()), which is correct for context.data/context.params.query targets.

Type declaration

Show Type Declarations

export type TraverseOptions = {
  /**
   * Called for every node of the traversal, with `neotraverse`'s context as
   * `this` — so `this.key`, `this.update(value)` and `this.remove()` are what
   * the transformation is written in terms of.
   */
  transformer: (transformContext: any) => any
  /**
   * Picks what is walked out of the hook context, e.g. `context.data`,
   * `context.params.query` or `context.result`. The returned object is
   * traversed in place — `context.params.query` is deep-cloned first, so
   * walking it leaves the caller's query untouched (other `params` members are
   * walked as they are).
   */
  getObject: (
    context: HookContext,
  ) => Record<string, any> | Record<string, any>[]
  /**
   * For `around` hooks only: run the traversal *after* `next()` instead of before.
   * Required when `getObject` targets `context.result`, which is only populated
   * once the service method has run. Defaults to `false` (run before `next()`),
   * which is correct for `context.data`/`context.params.query` targets.
   *
   * @default false
   */
  runAfter?: boolean
}
/**
 * Recursively walks and transforms fields in record(s) using `neotraverse`.
 * The `getObject` function extracts the target from the context, and `transformer`
 * is called for every node during traversal --- ideal for deep, structural transformations.
 *
 * @example
 * ```ts
 *
 *
 * app.service('users').hooks({
 *   after: {
 *     all: [traverse({ getObject: (ctx) => ctx.result, transformer: function () { if (this.key === 'password') this.remove() } })]
 *   }
 * })
 * ```
 *
 * @see https://utils.feathersjs.com/hooks/traverse.html
 */
export declare const traverse: <H extends HookContext = HookContext>({
  transformer,
  getObject,
  runAfter,
}: TraverseOptions) => {
  (context: H): void
  (context: H, next: NextFunction): Promise<void>
}

Argument	Type	Description
{ transformer, getObject, runAfter = false, }	TraverseOptions

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