Class LoaderBase<TDataLoaderId, TItemId, TRetrievedItem, TTransformedItem, TTransformParams>`Abstract`

Abstract base Kosmos Data loader class.

Type Parameters

TDataLoaderId
TItemId
TRetrievedItem = Record<string, any>
TTransformedItem = TRetrievedItem
TTransformParams extends {} = {}

Hierarchy

LoaderBase

Index

Constructors

constructor

new LoaderBase<TDataLoaderId, TItemId, TRetrievedItem, TTransformedItem, TTransformParams>(): LoaderBase<TDataLoaderId, TItemId, TRetrievedItem, TTransformedItem, TTransformParams>
Type Parameters
- TDataLoaderId
- TItemId
- TRetrievedItem = Record<string, any>
- TTransformedItem = TRetrievedItem
- TTransformParams extends {} = {}
Returns LoaderBase<TDataLoaderId, TItemId, TRetrievedItem, TTransformedItem, TTransformParams>

Properties

`Protected` `Abstract` serializeDataItemId

serializeDataItemId: ((id: TItemId) => string)

Type declaration

- (id: TItemId): string
- Serializes retrieved item ID to a string.
  Parameters
  - id: TItemId
  Returns string

`Protected` `Abstract` serializeDataLoaderId

serializeDataLoaderId: ((id: TDataLoaderId) => string)

Type declaration

- (id: TDataLoaderId): string
- Serializes Data Loader ID to a string.
  Parameters
  - id: TDataLoaderId
  Returns string

Methods

`Protected` `Abstract` buildDataLoader

buildDataLoader(context: KosmosUserContext<object>, dataLoaderId: TDataLoaderId): BatchLoader<TItemId, TRetrievedItem>
Builds DataLoader.

Should be overridden in child classes.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
- dataLoaderId: TDataLoaderId
  
  Class-specific DataLoader ID parameters.
Returns BatchLoader<TItemId, TRetrievedItem>
- Defined in src/backends/dataLoaders/LoaderBase.ts:173

clearCache

clearCache(context: KosmosUserContext<object>): void
Clears per-request data loaders cache.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
Returns void
- Defined in src/backends/dataLoaders/LoaderBase.ts:136

`Protected` getDataLoader

getDataLoader(context: KosmosUserContext<object>, params: TDataLoaderId): KosmosDataLoader<TItemId, TRetrievedItem>
Returns DataLoader instance.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
- params: TDataLoaderId
  
  Class specific params required to identify the DataLoader instance.
Returns KosmosDataLoader<TItemId, TRetrievedItem>
- Defined in src/backends/dataLoaders/LoaderBase.ts:87

`Protected` getDataLoadersMap

getDataLoadersMap(context: KosmosUserContext<object>): Map<undefined | string, KosmosDataLoader<TItemId, TRetrievedItem>>
Returns a map of DataLoaders for the given request.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
Returns Map<undefined | string, KosmosDataLoader<TItemId, TRetrievedItem>>
- Defined in src/backends/dataLoaders/LoaderBase.ts:116

retrieveItem

retrieveItem(context: KosmosUserContext<object>, requestParams: TDataLoaderId & TItemId, transformParams?: TTransformParams): Promise<null | TTransformedItem>
Retrieves an item using DataLoader.

Returns
The class specific response type or NULL.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
- requestParams: TDataLoaderId & TItemId
  
  Class specific request parameters.
- Optional transformParams: TTransformParams
  
  Class specific response item transformation params.
Returns Promise<null | TTransformedItem>
- Defined in src/backends/dataLoaders/LoaderBase.ts:71

`Protected` storageName

storageName(): string
The unique name of the in-context storage used by this specific Loader service.

Returns string
- Defined in src/backends/dataLoaders/LoaderBase.ts:191

`Protected` transform

transform(item: null | TRetrievedItem, context: KosmosUserContext<object>, dataLoaderId: TDataLoaderId, params?: TTransformParams): null | TTransformedItem | Promise<null | TTransformedItem>
The return value transformation callback.

Called after the item was retrieved from DataLoader. Child classes may override this method to perform transformation of the data being returned.
Parameters
- item: null | TRetrievedItem
  
  The item being retrieved from DataLoader.
- context: KosmosUserContext<object>
  
  The user context.
- dataLoaderId: TDataLoaderId
  
  The DataLoader identifier object which may contain properties used to initialize the Data Loader.
- Optional params: TTransformParams
  
  Class-specific transformation params.
Returns null | TTransformedItem | Promise<null | TTransformedItem>
- Defined in src/backends/dataLoaders/LoaderBase.ts:154

Class LoaderBase<TDataLoaderId, TItemId, TRetrievedItem, TTransformedItem, TTransformParams>Abstract

Type Parameters

TDataLoaderId

TItemId

TRetrievedItem = Record<string, any>

TTransformedItem = TRetrievedItem

TTransformParams extends {} = {}

Hierarchy

Index

Constructors

Properties

Methods

Constructors

constructor

Type Parameters

TDataLoaderId

TItemId

TRetrievedItem = Record<string, any>

TTransformedItem = TRetrievedItem

TTransformParams extends {} = {}

Returns LoaderBase<TDataLoaderId, TItemId, TRetrievedItem, TTransformedItem, TTransformParams>

Properties

Protected Abstract serializeDataItemId

Type declaration

Parameters

id: TItemId

Returns string

Protected Abstract serializeDataLoaderId

Type declaration

Parameters

id: TDataLoaderId

Returns string

Methods

Protected Abstract buildDataLoader

Parameters

context: KosmosUserContext<object>

dataLoaderId: TDataLoaderId

Returns BatchLoader<TItemId, TRetrievedItem>

clearCache

Parameters

context: KosmosUserContext<object>

Returns void

Protected getDataLoader

Parameters

context: KosmosUserContext<object>

params: TDataLoaderId

Returns KosmosDataLoader<TItemId, TRetrievedItem>

Protected getDataLoadersMap

Parameters

context: KosmosUserContext<object>

Returns Map<undefined | string, KosmosDataLoader<TItemId, TRetrievedItem>>

retrieveItem

Returns

Parameters

context: KosmosUserContext<object>

requestParams: TDataLoaderId & TItemId

Optional transformParams: TTransformParams

Returns Promise<null | TTransformedItem>

Protected storageName

Returns string

Protected transform

Parameters

item: null | TRetrievedItem

context: KosmosUserContext<object>

dataLoaderId: TDataLoaderId

Optional params: TTransformParams

Returns null | TTransformedItem | Promise<null | TTransformedItem>

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Class LoaderBase<TDataLoaderId, TItemId, TRetrievedItem, TTransformedItem, TTransformParams>`Abstract`

`Protected` `Abstract` serializeDataItemId

`Protected` `Abstract` serializeDataLoaderId

`Protected` `Abstract` buildDataLoader

`Protected` getDataLoader

`Protected` getDataLoadersMap

`Optional` transformParams: TTransformParams

`Protected` storageName

`Protected` transform

`Optional` params: TTransformParams