TWTwainJS

TWTwainJS

Main class for the TWTwainJS library.

Constructor

# new TWTwainJS(name, companyName, key, twConsole)

Creates an instance of TWTwainJS.

Parameters:
Name Type Description
name string

The name of the TWTwainJS instance.
companyName string

License company name
key string

License key
twConsole object

The console object to be used for logging. Used only for debugging purposes.
Source:

Members

# autoReconnect :boolean

Reconnect automatically when the connection to the client is lost, for example because the client restarted itself after a scanner failure (TWErrorCode.CLIENT_RESTARTING). The port range given to connectToClient is scanned again, with a growing pause between rounds, for up to reconnectTimeoutMs. TWEvent.SOCKET_CONNECTION_STATUS_CHANGED is raised with CLOSED when the connection drops (detail.reconnecting is true) and with CONNECTED once it is back (detail.reconnected is true); the attempts in between raise nothing. If the client does not come back in time, TWEvent.TW_ERROR is raised once. Set it to false when the integration reconnects on its own.

Type:
  • boolean
Source:

# id :string

The id of the twTwainJS instance. It is set automatically when the connect method succeeds.

Type:
  • string
Source:

# info :TWTwainJSInfo

Basic information about the twTwainJS instance.

Type:
Source:

# name :string

The name of the TWTwainJS instance.

Type:
  • string
Source:

# port :number

The port used for the socket communication. It is set automatically when the connect method succeeds.

Type:
  • number
Source:

# reconnectTimeoutMs :number

How long autoReconnect keeps trying, in milliseconds.

Type:
  • number
Source:

# scanResult :ScanResult

The result of the last scan.

Type:
Source:

Methods

# cancelConnect() → {boolean}

Stop looking for the client: the port walk started by connectToClient is abandoned and its promise is rejected with TWConnectCancelled; a running autoReconnect is cancelled too. Useful when the user sees that the client is not installed and does not want to wait for the whole port range. An established connection is not touched.

Source:
Returns:
  • true when a walk was in progress and has been stopped.
Type
boolean

# connectToClient(fromPort, toPort) → {Promise}

Connect to the TWTwain client and open the WebSocket connection trying to find a first valid port in the from and to range. If the connection is successful, the onConnected event is raised otherwise No valid socket found is raised. The same range is used again by autoReconnect if the connection is lost later.

Parameters:
Name Type Description
fromPort number

The starting port number in client port range.
toPort number

The ending port number in client port range.
Source:
Returns:
  • A promise that resolves when the connection is successful.
Type
Promise

# downloadFile(downloadMode, settings) → {Promise}

Download the specified file in the file format specified in the fileName extension. For every single file downloaded, TWEvent.SINGLE_FILE_DOWNLOADED is triggered. Once all the files are downloaded, TWEvent.DOWNLOAD_FINISHED is triggered.

Parameters:
Name Type Description
downloadMode TWDownloadMode

download mode. Allowed values are TWDownloadMode.LOCAL ("local") or TWDownloadMode.STANDARD ("standard"). Local mode saves the file to the local machine based on TWTwain client settings. Standard mode uses the browser's download functionality.
settings ScannedFileSettings

Scanned file settings.
Source:
Returns:
  • Promise object represents the download result.
Type
Promise

# getAvailableDevices() → {Promise}

Execute retrieving the available devices and current default device from the client. Once finished, event TWWEvent.DEVICE_LIST_RETRIEVED is triggered.

Source:
Returns:
  • Promise object represents the available devices retrieve result.
Type
Promise

# getCurrentSettings(capNames, deviceName) → {Promise}

Execute retrieving the current capability values from the client. Once finished, event TWEvent.CURRENT_SETTINGS_RECEIVED is triggered.

Parameters:
Name Type Description
capNames *

Array of capability names to retrieve the values for.
deviceName string

Name of the device to retrieve the capabilities from.
Source:
Returns:
  • Promise object represents the current settings retrieve result.
Type
Promise

# getDeviceInfo(deviceName, ignoreCurrentValues) → {Promise}

Open the specified scanner device and reads its capabilities and current values. Once opened, event TWEvent.DEVICE_INFO_RETRIEVIED is triggered with the device name and capabilities in the detail.

Parameters:
Name Type Default Description
deviceName string

Name of the device to open.
ignoreCurrentValues boolean false

If true, the current values of the capabilities are not retrieved. It could be good for performance. Default is false.
Source:
Returns:
  • Promise object represents the device info.
Type
Promise

# getFile(settings) → {Promise}

Retrieves the specified file(s) in the file format specified in the fileName extension. For every single file retrieved, TWEvent.SINGLE_FILE_RETRIEVED is triggered. Once all the files are retrieved, TWEvent.FILE_RETRIEVE_FINISHED is triggered.

Parameters:
Name Type Description
settings ScannedFileSettings

Scanned file settings.
Source:
Returns:
  • Promise object represents the file retrieve result.
Type
Promise

# scan(scanSettings) → {Promise}

Execute scanning from the TWTwain client using the specified settings in capability property. Once the page is scanned, TWEvent.PAGE_SCANNED is triggered. Once the scanning finishes, TWEvent.SCAN_FINISHED is triggered with scanFinishedStatus set to TWScanFinishedStatus.SUCCESS if the scanning is successful or TWScanFinishedStatus.ERROR if the scanning is not successful or TWScanFinishedStatus.CANCEL if the scanning is cancelled.

A page that fails to reach the browser does not fail the scan: the client keeps every page, so the resulting file is complete either way. Such a page is requested again automatically and leaves an empty slot in scanResult.images until it arrives. See ScanResult.missingPages().

The promise is rejected if the connection to the client is lost. There is no timeout, since with showUI the user may keep the scanner dialog open for as long as they like.

Parameters:
Name Type Description
scanSettings ScanSettings

Scan settings.
Source:
Returns:
  • Promise object represents the scan result.
Type
Promise