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TransferState

A key value store that is transferred from the application on the server side to the application on the client side.

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      class TransferState {
  get<T>(key: StateKey<T>, defaultValue: T): T
  set<T>(key: StateKey<T>, value: T): void
  remove<T>(key: StateKey<T>): void
  hasKey<T>(key: StateKey<T>)
  onSerialize<T>(key: StateKey<T>, callback: () => T): void
  toJson(): string
}
    

Description

TransferState will be available as an injectable token. To use it import ServerTransferStateModule on the server and BrowserTransferStateModule on the client.

The values in the store are serialized/deserialized using JSON.stringify/JSON.parse. So only boolean, number, string, null and non-class objects will be serialized and deserialzied in a non-lossy manner.

Methods

Get the value corresponding to a key. Return defaultValue if key is not found.

get<T>(key: StateKey<T>, defaultValue: T): T
      
      get<T>(key: StateKey<T>, defaultValue: T): T
    

Parameters

key

Type: StateKey.

defaultValue

Type: T.

Returns

T

Set the value corresponding to a key.

set<T>(key: StateKey<T>, value: T): void
      
      set<T>(key: StateKey<T>, value: T): void
    

Parameters

key

Type: StateKey.

value

Type: T.

Returns

void

Remove a key from the store.

remove<T>(key: StateKey<T>): void
      
      remove<T>(key: StateKey<T>): void
    

Parameters

key

Type: StateKey.

Returns

void

Test whether a key exists in the store.

hasKey<T>(key: StateKey<T>)
      
      hasKey<T>(key: StateKey<T>)
    

Parameters

key

Type: StateKey.

Register a callback to provide the value for a key when toJson is called.

onSerialize<T>(key: StateKey<T>, callback: () => T): void
      
      onSerialize<T>(key: StateKey<T>, callback: () => T): void
    

Parameters

key

Type: StateKey.

callback

Type: () => T.

Returns

void

Serialize the current state of the store to JSON.

toJson(): string
      
      toJson(): string
    

Parameters

There are no parameters.

Returns

string