namespace http://opcfoundation.org/UA/
nodeClass VariableType
typedDefinition DiscreteItemType i=2372
dataType Null
dataType Name VariantOptions i=0
isAbstract true
interface UAMultiStateValueDiscreteArrayEx<T, DT> {
    $extensionObject?: any;
    accessLevel: number;
    arrayDimensions: null | number[];
    browseName: QualifiedName;
    dataType: NodeId;
    dataTypeObj: UADataType;
    definition?: UAProperty<UAString, String>;
    enumValues: UAProperty<DTEnumValue[], ExtensionObject>;
    historizing: boolean;
    minimumSamplingInterval: number;
    nodeClass: Variable;
    nodeId: NodeId;
    nodeVersion?: UAVariableT<UAString, String>;
    onFirstBrowseAction?: ((this: BaseNode) => Promise<void>);
    parent: null | BaseNode;
    semantic_version: number;
    userAccessLevel?: number;
    valueAsText: UAProperty<LocalizedText[], LocalizedText>;
    valuePrecision?: UAProperty<number, Double>;
    valueRank: number;
    get accessRestrictions(): undefined | AccessRestrictionsFlag;
    get addressSpace(): IAddressSpace;
    get description(): LocalizedText;
    get displayName(): LocalizedText[];
    get modellingRule(): undefined | ModellingRuleType;
    get namespace(): INamespace;
    get namespaceIndex(): number;
    get namespaceUri(): string;
    get parentNodeId(): undefined | NodeId;
    get rolePermissions(): undefined | RolePermissionType[];
    get typeDefinition(): NodeId;
    get typeDefinitionObj(): UAVariableType;
    [captureRejectionSymbol]?<K>(error: Error, event: string | symbol, ...args: AnyRest): void;
    addListener<K>(eventName: string | symbol, listener: ((...args: any[]) => void)): this;
    addReference(options: AddReferenceOpts): void;
    allReferences(): UAReference[];
    asyncRefresh(oldestDate: PreciseClock, callback: CallbackT<DataValue>): void;
    asyncRefresh(oldestDate: PreciseClock): Promise<DataValue>;
    bindExtensionObject(optionalExtensionObject?: ExtensionObject | ExtensionObject[], options?: BindExtensionObjectOptions): null | ExtensionObject | ExtensionObject[];
    bindExtensionObjectArray(optionalExtensionObjectArray?: ExtensionObject[], options?: BindExtensionObjectOptions): null | ExtensionObject[];
    bindExtensionObjectScalar(optionalExtensionObject?: ExtensionObject, options?: BindExtensionObjectOptions): null | ExtensionObject;
    bindVariable(options?: BindVariableOptions, overwrite?: boolean): void;
    browseNode(browseDescription: BrowseDescriptionOptions2, session?: ISessionContext): ReferenceDescription[];
    browseNodeByTargetName(relativePathElement: RelativePathElement, isLast: boolean): NodeId[];
    changeDataType(newDataType: NodeIdLike, newValue?: VariantOptions): void;
    clone(options: CloneOptions, optionalFilter?: CloneFilter, extraInfo?: CloneExtraInfo): UAVariable;
    emit<K>(eventName: string | symbol, ...args: AnyRest): boolean;
    eventNames(): (string | symbol)[];
    findReference(referenceType: string | NodeId | UAReferenceType, isForward?: boolean): null | UAReference;
    findReferences(referenceType: string | NodeId | UAReferenceType, isForward?: boolean): UAReference[];
    findReferencesAsObject(referenceType: string | NodeId | UAReferenceType, isForward?: boolean): BaseNode[];
    findReferencesEx(referenceType: string | NodeId | UAReferenceType, browseDirection?: BrowseDirection): UAReference[];
    findReferencesExAsObject(referenceType: string | NodeId | UAReferenceType, browseDirection?: BrowseDirection): BaseNode[];
    findValueAsText(value: number | UInt64): Variant;
    fullName(): string;
    getAccessRestrictions(inherited: boolean): AccessRestrictionsFlag;
    getAggregates(): BaseNode[];
    getBasicDataType(): DataType;
    getChildByName(browseName: QualifiedNameOptions): null | BaseNode;
    getChildByName(browseName: string, namespaceIndex?: number): null | BaseNode;
    getComponentByName(componentName: QualifiedNameOptions): null | UAObject | UAVariable;
    getComponentByName(componentName: string, namespaceIndex?: number): null | UAObject | UAVariable;
    getComponents(): BaseNode[];
    getDisplayName(locale?: string): string;
    getEventSourceOfs(): BaseNode[];
    getEventSources(): BaseNode[];
    getMaxListeners(): number;
    getNotifiers(): BaseNode[];
    getProperties(): BaseNode[];
    getPropertyByName(propertyName: QualifiedNameOptions): null | UAVariable;
    getPropertyByName(propertyName: string, namespaceIndex?: number): null | UAVariable;
    getRolePermissions(inherited: boolean): null | RolePermissionType[];
    getValueAsNumber(): number[];
    getValueAsString(): string[];
    historyRead(context: ISessionContext, historyReadDetails:
        | HistoryReadDetails
        | ReadAtTimeDetails
        | ReadEventDetails
        | ReadProcessedDetails
        | ReadRawModifiedDetails, indexRange: null | NumericRange, dataEncoding: null | QualifiedNameLike, continuationData: ContinuationData): Promise<HistoryReadResult>;
    historyRead(context: ISessionContext, historyReadDetails:
        | HistoryReadDetails
        | ReadAtTimeDetails
        | ReadEventDetails
        | ReadProcessedDetails
        | ReadRawModifiedDetails, indexRange: null | NumericRange, dataEncoding: null | QualifiedNameLike, continuationData: ContinuationData, callback: CallbackT<HistoryReadResult>): void;
    install_extra_properties(): void;
    installExtensionObjectVariables(): void;
    isDisposed(): boolean;
    isEnumeration(): boolean;
    isExtensionObject(): boolean;
    isReadable(context: ISessionContext): boolean;
    isUserReadable(context: ISessionContext): boolean;
    isUserWritable(context: ISessionContext): boolean;
    isWritable(context: ISessionContext): boolean;
    listenerCount<K>(eventName: string | symbol, listener?: Function): number;
    listeners<K>(eventName: string | symbol): Function[];
    off<K>(eventName: string | symbol, listener: ((...args: any[]) => void)): this;
    on(eventName: "semantic_changed", eventHandler: (() => void)): this;
    on(eventName: "value_changed", eventHandler: ((dataValue: DataValue) => void)): this;
    once(eventName: "semantic_changed", eventHandler: (() => void)): this;
    once(eventName: "value_changed", eventHandler: ((dataValue: DataValue) => void)): this;
    prependListener<K>(eventName: string | symbol, listener: ((...args: any[]) => void)): this;
    prependOnceListener<K>(eventName: string | symbol, listener: ((...args: any[]) => void)): this;
    rawListeners<K>(eventName: string | symbol): Function[];
    readAttribute(context: null | ISessionContext, attributeId: AttributeIds, indexRange?: NumericRange, dataEncoding?: null | QualifiedNameLike): DataValue;
    readEnumValue(): EnumValue2;
    readValue(context?: null | ISessionContext, indexRange?: NumericRange, dataEncoding?: null | QualifiedNameLike): DataValueT<T, DT>;
    readValueAsync(context: null | ISessionContext): Promise<DataValueT<T, DT>>;
    readValueAsync(context: null | ISessionContext, callback: CallbackT<DataValueT<T, DT>>): void;
    removeAllListeners(eventName?: string | symbol): this;
    removeListener<K>(eventName: string | symbol, listener: ((...args: any[]) => void)): this;
    removeReference(referenceOpts: AddReferenceOpts): void;
    setAccessRestrictions(accessRestrictions: AccessRestrictionsFlag): void;
    setDescription(value: null | LocalizedTextLike): void;
    setDisplayName(value: LocalizedTextLike | LocalizedTextLike[]): void;
    setMaxListeners(n: number): this;
    setRolePermissions(rolePermissions: RolePermissionTypeOptions[]): void;
    setValue(value: string | number | Int64, options?: ISetStateOptions): void;
    setValueFromSource(value: VariantOptions, statusCode?: StatusCode, sourceTimestamp?: Date): void;
    touchValue(updateNow?: PreciseClock): void;
    writeAttribute(context: null | ISessionContext, writeValue: WriteValueOptions, callback: StatusCodeCallback): void;
    writeAttribute(context: null | ISessionContext, writeValue: WriteValueOptions): Promise<StatusCode>;
    writeEnumValue(value: string | number): void;
    writeValue(context: ISessionContext, dataValue: DataValueT<T, DT>, indexRange: null | NumericRange, callback: StatusCodeCallback): void;
    writeValue(context: ISessionContext, dataValue: DataValueT<T, DT>, callback: StatusCodeCallback): void;
    writeValue(context: ISessionContext, dataValue: DataValueT<T, DT>, indexRange?: null | NumericRange): Promise<StatusCode>;
}

Type Parameters

Hierarchy (view full)

Properties

Accessors

Methods

Properties

$extensionObject?: any
accessLevel: number

The AccessLevel Attribute is used to indicate how the Value of a Variable can be accessed (read/write) and if it contains current and/or historic data.

The AccessLevel does not take any user access rights into account, i.e. although the Variable is writable this may be restricted to a certain user / user group.

The {{link:AccessLevelType}}

arrayDimensions: null | number[]

This Attribute specifies the length of each dimension for an array value.

  • The Attribute is intended to describe the capability of the Variable, not the current size.
  • The number of elements shall be equal to the value of the valueRank Attribute.
  • Shall be null if valueRank <=0.
  • A value of 0 for an individual dimension indicates that the dimension has a variable length.

example

For example, if a Variable is defined by the following javascript array with 346 Int32 elements:

const myArray = new Array(346).fill(0);

then:

  • DataType would point to an Int32
  • the Variable's valueRank has the value 1 and,
  • the arrayDimensions is an array with one entry having the value 346.
{
dataType: "Int32",
valueRank: 1,
arrayDimensions: [346]
}

Note: the maximum length of an array transferred on the wire is 2147483647 (max Int32) and a multidimensional array is encoded as a one dimensional array.

browseName: QualifiedName
dataType: NodeId
dataTypeObj: UADataType
definition?: UAProperty<UAString, String>
historizing: boolean

The historizing attribute indicates whether the server is actively collecting data for the history of the variable.

This differs from the accessLevel Attribute which identifies if the variable has any historical data.

A value of true indicates that the server is actively collecting data.

A value of false indicates the server is not actively collecting data.

Default value is false.

minimumSamplingInterval: number

The MinimumSamplingInterval Attribute indicates how 'current' the Value of the Variable will be kept.

It specifies (in milliseconds) how fast the Server can reasonably sample the value for changes (see Part 4 for a detailed description of sampling interval).

A MinimumSamplingInterval of 0 indicates that the Server is to monitor the item continuously.

A MinimumSamplingInterval of -1 means indeterminate.

nodeClass: Variable
nodeId: NodeId
nodeVersion?: UAVariableT<UAString, String>

NodeVersion (Optional) String The NodeVersion Property is used to indicate the version of a Node. The NodeVersion Property is updated each time a Reference is added or deleted to the Node the Property belongs to. Attribute value changes do not cause the NodeVersion to change. Clients may read the NodeVersion Property or subscribe to it to determine when the structure of a Node has changed.

onFirstBrowseAction?: ((this: BaseNode) => Promise<void>)
parent: null | BaseNode
semantic_version: number
userAccessLevel?: number

The UserAccessLevel Attribute is used to indicate how the Value of a Variable can be accessed (read/write) and if it contains current or historic data taking user access rights into account.

The AccessLevelType is defined in 8.57.

valuePrecision?: UAProperty<number, Double>
valueRank: number

This Attribute indicates whether the Value Attribute of the Variable is an array and how many dimensions the array has. It may have the following values:

  • n > 1 : the Value is an array with the specified number of dimensions.
  • OneDimension (1): The value is an array with one dimension.
  • OneOrMoreDimensions (0): The value is an array with one or more dimensions.
  • Scalar (-1): The value is not an array.
  • Any (-2): The value can be a scalar or an array with any number of dimensions.
  • ScalarOrOneDimension (-3): The value can be a scalar or a one dimensional array.

NOTE:

  • All DataTypes are considered to be scalar, even if they have array-like semantics like ByteString and String.

Accessors

  • get accessRestrictions(): undefined | AccessRestrictionsFlag
  • Returns undefined | AccessRestrictionsFlag

  • get addressSpace(): IAddressSpace
  • Returns IAddressSpace

  • get description(): LocalizedText
  • Returns LocalizedText

  • get displayName(): LocalizedText[]
  • Returns LocalizedText[]

  • get modellingRule(): undefined | ModellingRuleType
  • Returns undefined | ModellingRuleType

  • get namespace(): INamespace
  • Returns INamespace

  • get namespaceIndex(): number
  • Returns number

  • get namespaceUri(): string
  • Returns string

  • get parentNodeId(): undefined | NodeId
  • Returns undefined | NodeId

  • get rolePermissions(): undefined | RolePermissionType[]
  • Returns undefined | RolePermissionType[]

  • get typeDefinition(): NodeId
  • Returns NodeId

  • get typeDefinitionObj(): UAVariableType
  • Returns UAVariableType

Methods

  • Type Parameters

    • K

    Parameters

    • error: Error
    • event: string | symbol
    • Rest...args: AnyRest

    Returns void

  • Alias for emitter.on(eventName, listener).

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol
    • listener: ((...args: any[]) => void)
        • (...args): void
        • Parameters

          • Rest...args: any[]

          Returns void

    Returns this

    v0.1.26

  • Parameters

    Returns void

  • Parameters

    Returns void

  • Parameters

    Returns void

  • Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

    Returns true if the event had listeners, false otherwise.

    import { EventEmitter } from 'node:events';
    const myEmitter = new EventEmitter();

    // First listener
    myEmitter.on('event', function firstListener() {
    console.log('Helloooo! first listener');
    });
    // Second listener
    myEmitter.on('event', function secondListener(arg1, arg2) {
    console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
    });
    // Third listener
    myEmitter.on('event', function thirdListener(...args) {
    const parameters = args.join(', ');
    console.log(`event with parameters ${parameters} in third listener`);
    });

    console.log(myEmitter.listeners('event'));

    myEmitter.emit('event', 1, 2, 3, 4, 5);

    // Prints:
    // [
    // [Function: firstListener],
    // [Function: secondListener],
    // [Function: thirdListener]
    // ]
    // Helloooo! first listener
    // event with parameters 1, 2 in second listener
    // event with parameters 1, 2, 3, 4, 5 in third listener

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol
    • Rest...args: AnyRest

    Returns boolean

    v0.1.26

  • Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.

    import { EventEmitter } from 'node:events';

    const myEE = new EventEmitter();
    myEE.on('foo', () => {});
    myEE.on('bar', () => {});

    const sym = Symbol('symbol');
    myEE.on(sym, () => {});

    console.log(myEE.eventNames());
    // Prints: [ 'foo', 'bar', Symbol(symbol) ]

    Returns (string | symbol)[]

    v6.0.0

  • find the the references that are strictly of type reference.

    The isForward boolean flag specifies the direction of the references to be looked for.

    Forward direction is implied if omitted.

    • will throw an exception if more than one reference exists with the referenceType.
    • will return null if no reference exists.

    Parameters

    Returns null | UAReference

  • find all the references that are strictly of type reference. The isForward boolean flag specifies the direction of the references to be looked for.

    Forward direction is implied if omitted.

    Parameters

    Returns UAReference[]

  • find all the nodes that are referenced by references strictly of type reference.

    The isForward boolean flag specifies the direction of the references to be looked for.

    Forward direction is implied if omitted.

    • will throw an exception if more than one reference exists with the referenceType.
    • will return null if no reference exists.

    Parameters

    Returns BaseNode[]

  • find all the references that are of type reference or a sub type of reference, in the direction specified by browseDirection

    • BrowseDirection.Forward direction is implied if browseDirection flags is omitted.

    Parameters

    Returns UAReference[]

  • find all the nodes that are referenced by references of type reference or a sub type of reference, in the direction specified by browseDirection

    • BrowseDirection.Forward direction is implied if browseDirection flags is omitted.

    Parameters

    Returns BaseNode[]

  • Parameters

    Returns Variant

  • return a complete name of this object by pre-pending name of its parent(s) to its own name

    Returns string

  • get effective accessRestrictions if (inherited is true) and node has no accessRestrictions, then default accessRestriction from namespace is returned if (inherited is false) and node has no accessRestrictions, then AccessRestrictionsFlag.None is returned

    Parameters

    • inherited: boolean

    Returns AccessRestrictionsFlag

  • returns the basic type of the variable that correspond to the dataType, that will be used in the dataValue.value.dataType property.

    Returns DataType

  • Parameters

    Returns null | BaseNode

  • Parameters

    • browseName: string
    • OptionalnamespaceIndex: number

    Returns null | BaseNode

  • Parameters

    • Optionallocale: string

      the locale of the text to return (e.g. en-EN)

    Returns string

  • return a array of the objects for which this node is an EventSource nodes = HasEventSource => self

    Returns BaseNode[]

  • return a array with the event source of this object. self = HasEventSource => nodes

    Returns BaseNode[]

  • Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to defaultMaxListeners.

    Returns number

    v1.0.0

  • Returns number[]

  • EnumValues is an array of EnumValueType. Each entry of the array represents one enumeration value with its integer notation, a human-readable representation, and help information. This represents enumerations with integers that are not zero-based or have gaps (e.g. 1, 2, 4, 8, 16). See OPC 10000-3 for the definition of this type. MultiStateValueDiscrete Variables expose the current integer notation in their Value Attribute. Clients will often read the EnumValues Property in advance and cache it to lookup a name or help whenever they receive the numeric representation.

    Returns string[]

  • private

    Returns void

  • Returns boolean

  • Returns boolean

  • Returns boolean

  • returns true if the accessLevel flag allows the variable to be readable in the specified context.

    Parameters

    Returns boolean

  • returns true if the userAccessLevel flag allows the variable to be readable in the specified context.

    Parameters

    Returns boolean

  • returns true if the userAccessLevel flag allows the variable to be writeable in the specified context.

    Parameters

    Returns boolean

  • returns true if the accessLevel flag allows the variable to be writeable in the specified context.

    Parameters

    Returns boolean

  • Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

      The name of the event being listened for

    • Optionallistener: Function

      The event handler function

    Returns number

    v3.2.0

  • Returns a copy of the array of listeners for the event named eventName.

    server.on('connection', (stream) => {
    console.log('someone connected!');
    });
    console.log(util.inspect(server.listeners('connection')));
    // Prints: [ [Function] ]

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

    Returns Function[]

    v0.1.26

  • Alias for emitter.removeListener().

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol
    • listener: ((...args: any[]) => void)
        • (...args): void
        • Parameters

          • Rest...args: any[]

          Returns void

    Returns this

    v10.0.0

  • Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

    server.on('connection', (stream) => {
    console.log('someone connected!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

    import { EventEmitter } from 'node:events';
    const myEE = new EventEmitter();
    myEE.on('foo', () => console.log('a'));
    myEE.prependListener('foo', () => console.log('b'));
    myEE.emit('foo');
    // Prints:
    // b
    // a

    Parameters

    • eventName: "semantic_changed"

      The name of the event.

    • eventHandler: (() => void)
        • (): void
        • Returns void

    Returns this

    v0.1.101

  • Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

    server.on('connection', (stream) => {
    console.log('someone connected!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

    import { EventEmitter } from 'node:events';
    const myEE = new EventEmitter();
    myEE.on('foo', () => console.log('a'));
    myEE.prependListener('foo', () => console.log('b'));
    myEE.emit('foo');
    // Prints:
    // b
    // a

    Parameters

    • eventName: "value_changed"

      The name of the event.

    • eventHandler: ((dataValue: DataValue) => void)
        • (dataValue): void
        • Parameters

          Returns void

    Returns this

    v0.1.101

  • Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

    server.once('connection', (stream) => {
    console.log('Ah, we have our first user!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

    import { EventEmitter } from 'node:events';
    const myEE = new EventEmitter();
    myEE.once('foo', () => console.log('a'));
    myEE.prependOnceListener('foo', () => console.log('b'));
    myEE.emit('foo');
    // Prints:
    // b
    // a

    Parameters

    • eventName: "semantic_changed"

      The name of the event.

    • eventHandler: (() => void)
        • (): void
        • Returns void

    Returns this

    v0.3.0

  • Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

    server.once('connection', (stream) => {
    console.log('Ah, we have our first user!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

    import { EventEmitter } from 'node:events';
    const myEE = new EventEmitter();
    myEE.once('foo', () => console.log('a'));
    myEE.prependOnceListener('foo', () => console.log('b'));
    myEE.emit('foo');
    // Prints:
    // b
    // a

    Parameters

    • eventName: "value_changed"

      The name of the event.

    • eventHandler: ((dataValue: DataValue) => void)
        • (dataValue): void
        • Parameters

          Returns void

    Returns this

    v0.3.0

  • Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

    server.prependListener('connection', (stream) => {
    console.log('someone connected!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

      The name of the event.

    • listener: ((...args: any[]) => void)

      The callback function

        • (...args): void
        • Parameters

          • Rest...args: any[]

          Returns void

    Returns this

    v6.0.0

  • Adds a one-timelistener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

    server.prependOnceListener('connection', (stream) => {
    console.log('Ah, we have our first user!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

      The name of the event.

    • listener: ((...args: any[]) => void)

      The callback function

        • (...args): void
        • Parameters

          • Rest...args: any[]

          Returns void

    Returns this

    v6.0.0

  • Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

    import { EventEmitter } from 'node:events';
    const emitter = new EventEmitter();
    emitter.once('log', () => console.log('log once'));

    // Returns a new Array with a function `onceWrapper` which has a property
    // `listener` which contains the original listener bound above
    const listeners = emitter.rawListeners('log');
    const logFnWrapper = listeners[0];

    // Logs "log once" to the console and does not unbind the `once` event
    logFnWrapper.listener();

    // Logs "log once" to the console and removes the listener
    logFnWrapper();

    emitter.on('log', () => console.log('log persistently'));
    // Will return a new Array with a single function bound by `.on()` above
    const newListeners = emitter.rawListeners('log');

    // Logs "log persistently" twice
    newListeners[0]();
    emitter.emit('log');

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

    Returns Function[]

    v9.4.0

  • from OPC.UA.Spec 1.02 part 4 5.10.2.4 StatusCodes Table 51 defines values for the operation level statusCode contained in the DataValue structure of each values element. Common StatusCodes are defined in Table 166.

    Read Operation Level Result Codes

    Symbolic Id Description
    BadNodeIdInvalid The syntax of the node id is not valid.
    BadNodeIdUnknown The node id refers to a node that does not exist in the server address space.
    BadAttributeIdInvalid BadAttributeIdInvalid The attribute is not supported for the specified node.
    BadIndexRangeInvalid The syntax of the index range parameter is invalid.
    BadIndexRangeNoData No data exists within the range of indexes specified.
    BadDataEncodingInvalid The data encoding is invalid. This result is used if no dataEncoding can be applied because an Attribute other than Value was requested or the DataType of the Value Attribute is not a subtype of the Structure DataType.
    BadDataEncodingUnsupported The server does not support the requested data encoding for the node. This result is used if a dataEncoding can be applied but the passed data encoding is not known to the Server.
    BadNotReadable The access level does not allow reading or subscribing to the Node.
    BadUserAccessDenied User does not have permission to perform the requested operation. (table 165)
    BadSecurityModeInsufficient The operation is not permitted over the current secure channel.
    BadInsufficientPrivileges The user does not have enough privileges to perform the requested operation.

    Parameters

    Returns DataValueT<T, DT>

  • Removes all listeners, or those of the specified eventName.

    It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

    Returns a reference to the EventEmitter, so that calls can be chained.

    Parameters

    • OptionaleventName: string | symbol

    Returns this

    v0.1.26

  • Removes the specified listener from the listener array for the event named eventName.

    const callback = (stream) => {
    console.log('someone connected!');
    };
    server.on('connection', callback);
    // ...
    server.removeListener('connection', callback);

    removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

    Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them fromemit() in progress. Subsequent events behave as expected.

    import { EventEmitter } from 'node:events';
    class MyEmitter extends EventEmitter {}
    const myEmitter = new MyEmitter();

    const callbackA = () => {
    console.log('A');
    myEmitter.removeListener('event', callbackB);
    };

    const callbackB = () => {
    console.log('B');
    };

    myEmitter.on('event', callbackA);

    myEmitter.on('event', callbackB);

    // callbackA removes listener callbackB but it will still be called.
    // Internal listener array at time of emit [callbackA, callbackB]
    myEmitter.emit('event');
    // Prints:
    // A
    // B

    // callbackB is now removed.
    // Internal listener array [callbackA]
    myEmitter.emit('event');
    // Prints:
    // A

    Because listeners are managed using an internal array, calling this will change the position indices of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

    When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

    import { EventEmitter } from 'node:events';
    const ee = new EventEmitter();

    function pong() {
    console.log('pong');
    }

    ee.on('ping', pong);
    ee.once('ping', pong);
    ee.removeListener('ping', pong);

    ee.emit('ping');
    ee.emit('ping');

    Returns a reference to the EventEmitter, so that calls can be chained.

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol
    • listener: ((...args: any[]) => void)
        • (...args): void
        • Parameters

          • Rest...args: any[]

          Returns void

    Returns this

    v0.1.26

  • Parameters

    Returns void

  • setAccessRestriction

    Parameters

    Returns void

  • Parameters

    Returns void

  • By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

    Returns a reference to the EventEmitter, so that calls can be chained.

    Parameters

    • n: number

    Returns this

    v0.3.5

  • Parameters

    • value: string | number | Int64
    • Optionaloptions: ISetStateOptions

    Returns void

  • Parameters

    Returns void

  • Parameters

    Returns void

  • write a variable attribute (callback version)

    Parameters

    • context: null | ISessionContext
    • writeValue: WriteValueOptions
    • callback: StatusCodeCallback

      example

        const writeValue = {
      attributeId: AttributeIds.Value,
      dataValue: new DataValue({
      statusCode: StatusCodes.Good,
      sourceTimestamp: new Date(),
      value: new Variant({ dataType: DataType.Double, value: 3.14 })
      }),
      nodeId
      };
      myVariable.writeAttribute(context,writeValue,(err, statusCode) => {
      if (err) { console.log("Write has failed"); return; }
      console.log("write statusCode = ",statusCode.toString());
      });

    Returns void

  • write a variable attribute (async/await version)

    Parameters

    • context: null | ISessionContext
    • writeValue: WriteValueOptions

      example

      try {
      const writeValue = {
      attributeId: AttributeIds.Value,
      dataValue: new DataValue({
      statusCode: StatusCodes.Good,
      sourceTimestamp: new Date(),
      value: new Variant({ dataType: DataType.Double, value: 3.14 })
      }),
      nodeId
      };
      const statusCode = await myVariable.writeAttribute(context,writeValue);
      } catch(err) {
      console.log("Write has failed");
      return;
      }
      console.log("write statusCode = ", statusCode.toString());

    Returns Promise<StatusCode>

  • precondition: UAVariable must have a dataType deriving from "Enumeration"

    Parameters

    • value: string | number

    Returns void