@dxfeed/widgets-api
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Getting StartedBasic UsageImport packageConfigure & Create connectionConfigure & Create subscriptionChange symbols in subscriptionGet events from streamClose subscription streamClose connectionPlayground

Basic Usage

Import package

import DXClient from '@dxfeed/widgets-api'

Configure & Create connection

Create instance of DXClient and set web socket address and open connection.

import DXClient from '@dxfeed/widgets-api'
const client = new DXClient('wss://CLIENT_NAME.dxfeed.com/api/rsocket')

Configure & Create subscription

You should specify the record and the requested symbols.

import { QuoteSubscription } from '@dxfeed/widgets-api/records/Quote'
const subscription = await client.subscribe(
  new QuoteSubscription(
    ['AAPL'] /* symbols */
  )
)

The full list of records can be found here:

import { /* Subscription */ } from '@dxfeed/widgets-api/records/*'

You can specify fields you want to request for each type of event. This can be achieved by passing a list of them as a second parameter of Subscription. If no value provided (i.e. parameter is undefined), a default set of fields will be requested. List of event types with all available fields for each of them can be found here.

client.subscribe(
  new QuoteSubscription(
    symbols,
    ['eventSymbol', 'bidPrice'] /* fields */
  )
)

NOTE: eventSymbol field is mandatory for all types of events. If you want to request a subset of fields, you must include eventSymbol.

Some of the events may may be requested using timed subscription (i.e. with inclusion of historical data). These are:

  • Candle
  • Greeks
  • TheoPrice
  • TimeAndSale
  • Underlying

For timed subscription you should also provide time to start subscription from.

client.subscribe(
  new CandleSubscription(
    symbols,
    fields,
    1500000000000 /* from time */
  )
)

NOTE: for timed events requested with custom selection of fields, an eventFlags field is also mandatory.

/* Timed subscription, requesting a default set of fields */
client.subscribe(
  new CandleSubscription(
    symbols,
    undefined,
    1500000000000
  )
)
/* Timed subscription, requesting a custom set of fields */
client.subscribe(
  new CandleSubscription(
    symbols,
    ['eventSymbol', 'eventFlags', 'high', 'low'],
    1500000000000
  )
)

Change symbols in subscription

Add symbols

subscription.addSymbols(['MSFT'])

Remove symbols

subscription.removeSymbols(['AAPL'])

Get events from stream

After an open subscription, you can listen to events from the stream.

const stream = subscription.getStream()
stream.subscribe({
  onSubscribe: sub => {
    sub.request(Number.MAX_SAFE_INTEGER) // set backpressure
  },
  onNext: handleEvents,
})

onNext its event handler for process incoming events.

import { Quote } from '@dxfeed/widgets-api/records/Quote'
const handleEvents = (events: Quote[]) => {
  /* process events */
}

Close subscription stream

All onSubscribe callbacks that are called with a subscription, you need to call the subs.close method to close the stream.

stream.subscribe({
  onSubscribe: sub => {
    setTimeout(() => sub.close(), 5000) // close after 5s
  },
  onNext: console.log,
})

Close connection

If you need to close the web socket connection

client.close()