Polled<S, K, V>

An external resource that is refreshed at some polling interval.

Type Parameters

Type Parameter	Description
S extends Json	Type of data received from external resource.
K extends Json	Type of keys.
V extends Json	Type of values.

Implements

• ExternalResource

Constructors

new Polled()

new Polled<S, K, V>(
   url, 
   duration, 
   conv, 
   encodeParams, 
   options?): Polled<S, K, V>

Construct a Polled external resource.

The URL of the external resource is formed by appending the given base url and the result of encodeParams(params) where params are the parameters provided when instantiating the resource.

Note that the result of encodeParams contains the ? separator, but it need not be at the beginning of the returned string, so some parameters can be used in part of the URL preceding the ?.

Parameters

Parameter	Type	Default value	Description
url	string	undefined	HTTP endpoint of external resource to poll.
duration	number	undefined	Refresh interval, in milliseconds.
conv	(data) => Entry<K, V>[]	undefined	Function to convert data of type S received from external resource to key-value entries.
encodeParams	(params) => string	defaultParamEncoder	Function to use to encode params of type Json for external resource request.
options?	{ headers: {}; timeout: number; }	undefined	Optional parameters.
options.headers?	{}	undefined	Additional headers to add to request.
options.timeout?	number	undefined	Timeout for request, in milliseconds. Defaults to 1000ms.

Returns

Polled<S, K, V>

Methods

close()

close(instance): void

Parameters

Parameter	Type
instance	string

Returns

void

Implementation of

ExternalResource.close

---

open()

open(
   instance, 
   params, 
   callbacks): void

Parameters

Parameter	Type
instance	string
params	Json
callbacks	{ error: (error) => void; loading: () => void; update: (updates, isInit) => void; }
callbacks.error	(error) => void
callbacks.loading	() => void
callbacks.update	(updates, isInit) => void

Returns

void

Implementation of

ExternalResource.open