Event (LibSBML Java API)

java.lang.Object
- org.sbml.libsbml.SBase
- - org.sbml.libsbml.Event

```
public class Event
extends SBase
```
A discontinuous SBML event.
An SBML Event object defines when the event can occur, the variables that are affected by it, how the variables are affected, and the event's relationship to other events. The effect of the event can optionally be delayed after the occurrence of the condition which invokes it.
The operation of Event is divided into two phases (even when the event is not delayed): one when the event is triggered, and the other when the event is executed. Trigger objects define the conditions for triggering an event, Delay objects define when the event is actually executed, EventAssignment objects define the effects of executing the event, and (in SBML Level 3) Priority objects influence the order of EventAssignment performance in cases of simultaneous events. Please consult the descriptions of Trigger, Delay, EventAssignment and Priority for more information.

SBML Level/Version differences

SBML Level 3

SBML Level 3 introduces several changes to the structure and components of Events compared to SBML Level 2. These changes fall into two main categories: changes to what is optional or required, and additions of new attributes and elements.
- The attribute 'useValuesFromTriggerTime' on Event is mandatory (it was optional in Level 2)
- Event's 'listOfEventAssignments' element (of class ListOfEventAssignments) is optional (it was mandatory in Level 2)
- Event's 'priority' element (of class Priority) is new in Level 3 and
- The Trigger object gains new mandatory attributes (described as part of the definition of Trigger).
The changes to the attributes of Event are described below the changes to Trigger and Priority are described in their respective sections.

SBML Level 2

In SBML Level 2 versions before Version 4, the semantics of Event time delays were defined such that the expressions in the event's assignments were always evaluated at the time the event was triggered. This definition made it difficult to define an event whose assignment formulas were meant to be evaluated at the time the event was executed (i.e., after the time period defined by the value of the Delay element). In SBML Level 2 Version 4 and in Level 3, the attribute 'useValuesFromTriggerTime' on Event allows a model to indicate the time at which the event's assignments are intended the values of the assignment formulas are computed at the moment the event is triggered, not after the delay. If 'useValuesFromTriggerTime'= false, it means that the formulas in the event's assignments are to be computed after the delay, at the time the event is executed.
The definition of Event in SBML Level 2 Versions 1 and 2 includes an additional attribute called 'timeUnits', which allowed the time units of the Delay to be set explicitly. Later Versions of SBML Level 2 as well as SBML Level 3 do not define this attribute. LibSBML supports this attribute for compatibility with previous versions of SBML Level 2 however, if a model in SBML Level 3 or Level 2 Versions 3&ndash4 format sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
The attribute 'useValuesFromTriggerTime' was introduced in SBML Level 2 Version 4. Models defined in prior Versions of SBML Level 2 cannot use this attribute, and SBMLDocument.checkConsistency() will report an error if they do.

Semantics of events in SBML Level 3 Version 1

The detailed semantics of events are described in the specification documents for each SBML Level/Version. Here we include the description from the SBML Level 1 Version 1. Any transition of a Trigger object's 'math' formula from the value false to true will cause the enclosing Event object to trigger. Such a transition is not possible at the very start of a simulation (i.e., at time t = 0) unless the Trigger object's 'initialValue' attribute has a value of false this defines the value of the trigger formula to be false immediately prior to the start of simulation, thereby giving it the potential to change in value from false to true when the formula is evaluated at t = 0. If 'initialValue'=true, then the trigger expression cannot transition from false to true at t = 0 but may do so at some time t > 0.
Consider an Event object definition E with delay d in which the Trigger object's 'math' formula makes a transition in value from false to true at times t₁ and t₂. The EventAssignment within the Event object will have effect at t₁ + d and t₂ + d irrespective of the relative times of t₁ and t₂. For example, events can 'overlap' so that t₁ < t₂ < t₁ + d still causes an event assignments to occur at t₁ + d and t₂ + d.
It is entirely possible for two events to be executed simultaneously, and it is possible for events to trigger other events (i.e., an event assignment can cause an event to trigger). This leads to several points:
- A software package should retest all event triggers after executing an event assignment in order to account for the possibility that the assignment causes another event trigger to transition from false to true. This check should be made after each individual Event object's execution, even when several events are to be executed simultaneously.
- Any Event object whose Trigger 'persistent' attribute has the value false must have its trigger expression reevaluated continuously between when the event is triggered and when it is executed. If its trigger expression ever evaluates to false, it must be removed from the queue of events pending execution and treated as any other event whose trigger expression evaluates to false.
- Although the precise time at which events are executed is not resolved beyond the given execution point in simulated time, it is assumed that the order in which the events occur is resolved. This order can be significant in determining the overall outcome of a given simulation. When an event X triggers another event Y and event Y has zero delay, then event Y is added to the existing set of simultaneous events that are pending execution. Events X and Y form a cascade of events at the same point in simulation time. An event such as Y may have a special priority if it contains a Priority subobject.
- All events in a model are open to being in a cascade. The position of an event in the event queue does not affect whether it can be in the cascade: event Y can be triggered whether it is before or after X in the queue of events pending execution. A cascade of events can be potentially infinite (never terminate) when this occurs a simulator should indicate this has occurred&mdashit is incorrect for a simulator to break a cascade arbitrarily and continue the simulation without at least indicating that the infinite cascade occurred.
- Simultaneous events having no defined priorities are executed in an undefined order. This does not mean that the behavior of the simulation is completely undefined merely that the order of execution of these particular events is undefined. A given simulator may use any algorithm to choose an order as long as every event is executed exactly once.
- Events with defined priorities are executed in the order implied by their Priority 'math' formula values, with events having higher priorities being executed ahead of events with lower priorities, and events with identical priorities being executed in a random order with respect to one another (as determined at run-time by some random algorithm equivalent to coin-flipping). Newly-triggered events that are to be executed immediately (i.e., if they define no delays) should be inserted into the queue of events pending execution according to their priorities: events with higher priority values value must be inserted ahead of events with lower priority values and after any pending events with even higher priorities, and inserted randomly among pending events with the same priority values. Events without Priority objects must be inserted into the queue in some fashion, but the algorithm used to place it in the queue is undefined. Similarly, there is no restriction on the order of a newly-inserted event with a defined Priority with respect to any other pending Event without a defined Priority.
- A model variable that is the target of one or more event assignments can change more than once when simultaneous events are processed at some time point t. The model's behavior (output) for such a variable is the value of the variable at the end of processing all the simultaneous events at time t.
See Also:

Trigger, Priority, Delay, EventAssignment

Constructor Summary

Constructors
Constructor and Description
`Event(Event orig)` Copy constructor creates a copy of this `Event`.
`Event(long level, long version)` Creates a new `Event` using the given SBML `level` and `version` values.
`Event(SBMLNamespaces sbmlns)` Creates a new `Event` using the given `SBMLNamespaces` object `sbmlns`.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`addEventAssignment(EventAssignment ea)` Appends a copy of the given `EventAssignment` to this `Event`.
`Event`	`cloneObject()` Creates and returns a deep copy of this `Event` object.
`void`	`connectToChild()`
`Delay`	`createDelay()` Creates a new, empty `Delay`, adds it to this `Event` and returns the `Delay`.
`EventAssignment`	`createEventAssignment()` Creates a new, empty `EventAssignment`, adds it to this `Event`'s list of event assignments and returns the `EventAssignment`.
`Priority`	`createPriority()` (SBML Level 3 only) Creates a new, empty `Priority`, adds it to this `Event` and returns the `Priority`.
`Trigger`	`createTrigger()` Creates a new, empty `Trigger`, adds it to this `Event` and returns the `Trigger`.
`void`	`delete()` Explicitly deletes the underlying native object.
`Delay`	`getDelay()` Get the assignment delay portion of this `Event`, if there is one.
`SBase`	`getElementByMetaId(java.lang.String metaid)` Returns the first child element it can find with the given `metaid`, or `null` if no such object is found.
`SBase`	`getElementBySId(java.lang.String id)` Returns the first child element found that has the given `id` in the model-wide SId namespace, or `null` if no such object is found.
`java.lang.String`	`getElementName()` Returns the XML element name of this object, which for `Event`, is always `'event'.`
`EventAssignment`	`getEventAssignment(long n)` Return a specific `EventAssignment` object of this `Event`.
`EventAssignment`	`getEventAssignment(java.lang.String variable)` Return the event assignment indicated by the given `variable`.
`java.lang.String`	`getId()` Returns the value of the 'id' attribute of this `Event`.
`ListOfEventAssignments`	`getListOfEventAssignments()` Returns the list of event assignments for this `Event`.
`java.lang.String`	`getName()` Returns the value of the 'name' attribute of this `Event`.
`long`	`getNumEventAssignments()` Returns the number of `EventAssignment` objects attached to this `Event`.
`Priority`	`getPriority()` (SBML Level 3 only) Get the event priority portion of this `Event`.
`java.lang.String`	`getTimeUnits()` Get the value of the 'timeUnits' attribute of this `Event`, if it has one.
`Trigger`	`getTrigger()` Get the event trigger portion of this `Event`.
`int`	`getTypeCode()` Returns the libSBML type code of this object instance.
`boolean`	`getUseValuesFromTriggerTime()` Get the value of the 'useValuesFromTriggerTime' attribute of this `Event`.
`boolean`	`hasRequiredAttributes()` Predicate returning `true` if all the required attributes for this `Event` object have been set.
`boolean`	`hasRequiredElements()` Predicate returning `true` if all the required elements for this `Event` object have been set.
`void`	`initDefaults()` Initializes the fields of this `Event` object to 'typical' default values.
`boolean`	`isSetDelay()` Predicate for testing whether the delay for this `Event` is set.
`boolean`	`isSetId()` Predicate returning `true` if this `Event`'s 'id' attribute is set.
`boolean`	`isSetName()` Predicate returning `true` if this `Event`'s 'name' attribute is set.
`boolean`	`isSetPriority()` (SBML Level 3 only) Predicate for testing whether the priority for this `Event` is set.
`boolean`	`isSetTimeUnits()` Predicate for testing whether the 'timeUnits' attribute of this `Event` is set.
`boolean`	`isSetTrigger()` Predicate for testing whether the trigger for this `Event` is set.
`boolean`	`isSetUseValuesFromTriggerTime()` Predicate for testing whether the 'useValuesFromTriggerTime' attribute of this `Event` is set.
`EventAssignment`	`removeEventAssignment(long n)` Removes the nth `EventAssignment` object from this `Event` object and returns a pointer to it.
`EventAssignment`	`removeEventAssignment(java.lang.String variable)` Removes the `EventAssignment` object with the given 'variable' attribute from this `Event` object and returns a pointer to it.
`int`	`setDelay(Delay delay)` Sets the delay definition of this `Event` to a copy of the given `Delay` object instance.
`int`	`setId(java.lang.String sid)` Sets the value of the 'id' attribute of this `Event`.
`int`	`setName(java.lang.String name)` Sets the value of the 'name' attribute of this `Event`.
`int`	`setPriority(Priority priority)` (SBML Level 3 only) Sets the priority definition of this `Event` to a copy of the given `Priority` object instance.
`int`	`setTimeUnits(java.lang.String sid)` Sets the 'timeUnits' attribute of this `Event` to a copy of `sid`.
`int`	`setTrigger(Trigger trigger)` Sets the trigger definition of this `Event` to a copy of the given `Trigger` object instance.
`int`	`setUseValuesFromTriggerTime(boolean value)` Sets the 'useValuesFromTriggerTime' attribute of this `Event` to a `value`.
`int`	`unsetDelay()` Unsets the `Delay` of this `Event`.
`int`	`unsetId()` Unsets the value of the 'id' attribute of this `Event`.
`int`	`unsetName()` Unsets the value of the 'name' attribute of this `Event`.
`int`	`unsetPriority()` (SBML Level 3 only) Unsets the `Priority` of this `Event`.
`int`	`unsetTimeUnits()` Unsets the 'timeUnits' attribute of this `Event`.
`int`	`unsetTrigger()` Unsets the `Trigger` of this `Event`.
`int`	`unsetUseValuesFromTriggerTime()` Unsets the value of the 'useValuesFromTriggerTime' attribute of this `Event`.

Methods inherited from class org.sbml.libsbml.SBase
addCVTerm, addCVTerm, appendAnnotation, appendAnnotation, appendNotes, appendNotes, deleteDisabledPlugins, deleteDisabledPlugins, disablePackage, enablePackage, equals, getAncestorOfType, getAncestorOfType, getAnnotation, getAnnotationString, getColumn, getCVTerm, getCVTerms, getDisabledPlugin, getLevel, getLine, getListOfAllElements, getListOfAllElements, getListOfAllElementsFromPlugins, getListOfAllElementsFromPlugins, getMetaId, getModel, getModelHistory, getNamespaces, getNotes, getNotesString, getNumCVTerms, getNumDisabledPlugins, getNumPlugins, getPackageName, getPackageVersion, getParentSBMLObject, getPlugin, getPlugin, getPrefix, getResourceBiologicalQualifier, getResourceModelQualifier, getSBMLDocument, getSBOTerm, getSBOTermAsURL, getSBOTermID, getURI, getVersion, hashCode, hasValidLevelVersionNamespaceCombination, isPackageEnabled, isPackageURIEnabled, isPkgEnabled, isPkgURIEnabled, isSetAnnotation, isSetMetaId, isSetModelHistory, isSetNotes, isSetSBOTerm, isSetUserData, matchesRequiredSBMLNamespacesForAddition, matchesSBMLNamespaces, removeFromParentAndDelete, removeTopLevelAnnotationElement, removeTopLevelAnnotationElement, removeTopLevelAnnotationElement, renameMetaIdRefs, renameSIdRefs, renameUnitSIdRefs, replaceTopLevelAnnotationElement, replaceTopLevelAnnotationElement, setAnnotation, setAnnotation, setMetaId, setModelHistory, setNamespaces, setNotes, setNotes, setNotes, setSBOTerm, setSBOTerm, toSBML, toXMLNode, unsetAnnotation, unsetCVTerms, unsetMetaId, unsetModelHistory, unsetNotes, unsetSBOTerm, unsetUserData

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Event
```
public Event(long level,
             long version)
      throws SBMLConstructorException
```
    Creates a new Event using the given SBML level and version values.
    
    Parameters:
    
    level - a long integer, the SBML Level to assign to this Event
    
    version - a long integer, the SBML Version to assign to this Event
    
    Throws:
    
    SBMLConstructorException - Thrown if the given level and version combination are invalid or if this object is incompatible with the given level and version.
    
    "Note:"
    
    Attempting to add an object to an SBMLDocument having a different combination of SBML Level, Version and XML namespaces than the object itself will result in an error at the time a caller attempts to make the addition. A parent object must have compatible Level, Version and XML namespaces. (Strictly speaking, a parent may also have more XML namespaces than a child, but the reverse is not permitted.) The restriction is necessary to ensure that an SBML model has a consistent overall structure. This requires callers to manage their objects carefully, but the benefit is increased flexibility in how models can be created by permitting callers to create objects bottom-up if desired. In situations where objects are not yet attached to parents (e.g., SBMLDocument), knowledge of the intented SBML Level and Version help libSBML determine such things as whether it is valid to assign a particular value to an attribute.
  - Event
```
public Event(SBMLNamespaces sbmlns)
      throws SBMLConstructorException
```
    Creates a new Event using the given SBMLNamespaces object sbmlns.
    
    The SBMLNamespaces object encapsulates SBML Level/Version/namespaces information. It is used to communicate the SBML Level, Version, and (in Level 3) packages used in addition to SBML Level 3 Core. A common approach to using libSBML's SBMLNamespaces facilities is to create an SBMLNamespaces object somewhere in a program once, then hand that object as needed to object constructors that accept SBMLNamespaces as arguments.
    
    Parameters:
    
    sbmlns - an SBMLNamespaces object.
    
    Throws:
    
    SBMLConstructorException - Thrown if the given sbmlns is inconsistent or incompatible with this object.
    
    "Note:"
    
    Attempting to add an object to an SBMLDocument having a different combination of SBML Level, Version and XML namespaces than the object itself will result in an error at the time a caller attempts to make the addition. A parent object must have compatible Level, Version and XML namespaces. (Strictly speaking, a parent may also have more XML namespaces than a child, but the reverse is not permitted.) The restriction is necessary to ensure that an SBML model has a consistent overall structure. This requires callers to manage their objects carefully, but the benefit is increased flexibility in how models can be created by permitting callers to create objects bottom-up if desired. In situations where objects are not yet attached to parents (e.g., SBMLDocument), knowledge of the intented SBML Level and Version help libSBML determine such things as whether it is valid to assign a particular value to an attribute.
  - Event
```
public Event(Event orig)
      throws SBMLConstructorException
```
    Copy constructor creates a copy of this Event.
    
    Parameters:
    
    orig - the object to copy.
    
    Throws:
    
    SBMLConstructorException
- Method Detail
  - delete
```
public void delete()
```
    Explicitly deletes the underlying native object.
    In general, application software will not need to call this method directly. The Java language binding for libSBML is implemented as a language wrapper that provides a Java interface to libSBML's underlying C++/C code. Some of the Java methods return objects that are linked to objects created not by Java code, but by C++ code. The Java objects wrapped around them will be deleted when the garbage collector invokes the corresponding C++ finalize() methods for the objects. The finalize() methods in turn call the Event.delete() method on the libSBML object.
    This method is exposed in case calling programs want to ensure that the underlying object is freed immediately, and not at some arbitrary time determined by the Java garbage collector. In normal usage, callers do not need to invoke Event.delete() themselves.
    
    Overrides:
    
    delete in class SBase
  - cloneObject
```
public Event cloneObject()
```
    Creates and returns a deep copy of this Event object.
    
    Overrides:
    
    cloneObject in class SBase
    
    Returns:
    
    the (deep) copy of this Event object.
  - initDefaults
```
public void initDefaults()
```
    Initializes the fields of this Event object to 'typical' default values.
    The SBML Event component has slightly different aspects and default attribute values in different SBML Levels and Versions. This method sets the values to certain common defaults, based mostly on what they are in SBML Level 2. Specifically:
    - Sets attribute 'spatialDimensions' to 3
  - getElementBySId
```
public SBase getElementBySId(java.lang.String id)
```
    Returns the first child element found that has the given id in the model-wide SId namespace, or null if no such object is found.
    
    Overrides:
    
    getElementBySId in class SBase
    
    Parameters:
    
    id - string representing the id of objects to find
    
    Returns:
    
    pointer to the first element found with the given id.
  - getElementByMetaId
```
public SBase getElementByMetaId(java.lang.String metaid)
```
    Returns the first child element it can find with the given metaid, or null if no such object is found.
    
    Overrides:
    
    getElementByMetaId in class SBase
    
    Parameters:
    
    metaid - string representing the metaid of objects to find
    
    Returns:
    
    pointer to the first element found with the given metaid.
  - getId
```
public java.lang.String getId()
```
    Returns the value of the 'id' attribute of this Event.
    
    Overrides:
    
    getId in class SBase
    
    Returns:
    
    the id of this Event.
  - getName
```
public java.lang.String getName()
```
    Returns the value of the 'name' attribute of this Event.
    
    Overrides:
    
    getName in class SBase
    
    Returns:
    
    the name of this Event.
  - getTrigger
```
public Trigger getTrigger()
```
    Get the event trigger portion of this Event.
    
    Returns:
    
    the Trigger object of this Event.
  - getDelay
```
public Delay getDelay()
```
    Get the assignment delay portion of this Event, if there is one.
    
    Returns:
    
    the delay of this Event if one is defined, or null if none is defined.
  - getPriority
```
public Priority getPriority()
```
    (SBML Level 3 only) Get the event priority portion of this Event.
    
    Returns:
    
    the Priority object of this Event.
    
    "Note:"
    
    The element 'priority' is available in SBML Level 3 Version 1 Core, but is not present in lower Levels of SBML.
  - getTimeUnits
```
public java.lang.String getTimeUnits()
```
    Get the value of the 'timeUnits' attribute of this Event, if it has one.
    
    Returns:
    
    the value of the attribute 'timeUnits' as a string.
    
    "Warning:"
    
    Definitions of Event in SBML Level 2 Versions 1 and 2 included the additional attribute called 'timeUnits', but it was removed in SBML Level 2 Version 3. LibSBML supports this attribute for compatibility with previous versions of SBML Level 2, but its use is discouraged since models in Level 2 Versions 3 and 4 cannot contain it. If a Version 3 or 4 model sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
  - getUseValuesFromTriggerTime
```
public boolean getUseValuesFromTriggerTime()
```
    Get the value of the 'useValuesFromTriggerTime' attribute of this Event.
    
    The optional Delay on Event means there are two times to consider when computing the results of an event: the time at which the event is triggered, and the time at which assignments are executed. It is also possible to distinguish between the time at which the EventAssignment's expression is calculated, and the time at which the assignment is made: the expression could be evaluated at the same time the assignments are performed, i.e., when the event is executed, but it could also be defined to be evaluated at the time the event is triggered.
    In SBML Level 2 versions prior to Version 4, the semantics of Event time delays were defined such that the expressions in the event's assignments were always evaluated at the time the event was triggered. This definition made it difficult to define an event whose assignment formulas were meant to be evaluated at the time the event was executed (i.e., after the time period defined by the value of the Delay element). In SBML Level 2 Version 4, the attribute 'useValuesFromTriggerTime' on Event allows a model to indicate the time at which the event's assignments are intended to be evaluated. In SBML Level 2, the attribute has a default value of true, which corresponds to the interpretation of event assignments prior to Version 4: the values of the assignment formulas are computed at the moment the event is triggered, not after the delay. If 'useValuesFromTriggerTime'=false, it means that the formulas in the event's assignments are to be computed after the delay, at the time the event is executed. In SBML Level 3, the attribute is mandatory, not optional, and all events must specify a value for it.
    
    Returns:
    
    the value of the attribute 'useValuesFromTriggerTime' as a boolean.
    
    "Warning:"
    
    The attribute 'useValuesFromTriggerTime' was introduced in SBML Level 2 Version 4. It is not valid in models defined using SBML Level 2 versions prior to Version 4. If a Level 2 Version 1&ndash3 model sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
  - isSetId
```
public boolean isSetId()
```
    Predicate returning true if this Event's 'id' attribute is set.
    
    Overrides:
    
    isSetId in class SBase
    
    Returns:
    
    true if the 'id' attribute of this Event is set, false otherwise.
  - isSetName
```
public boolean isSetName()
```
    Predicate returning true if this Event's 'name' attribute is set.
    
    Overrides:
    
    isSetName in class SBase
    
    Returns:
    
    true if the 'name' attribute of this Event is set, false otherwise.
  - isSetTrigger
```
public boolean isSetTrigger()
```
    Predicate for testing whether the trigger for this Event is set.
    
    Returns:
    
    true if the trigger of this Event is set, false otherwise.
  - isSetDelay
```
public boolean isSetDelay()
```
    Predicate for testing whether the delay for this Event is set.
    
    Returns:
    
    true if the delay of this Event is set, false otherwise.
  - isSetPriority
```
public boolean isSetPriority()
```
    (SBML Level 3 only) Predicate for testing whether the priority for this Event is set.
    
    Returns:
    
    true if the priority of this Event is set, false otherwise.
    
    "Note:"
    
    The element 'priority' is available in SBML Level 3 Version 1 Core, but is not present in lower Levels of SBML.
  - isSetTimeUnits
```
public boolean isSetTimeUnits()
```
    Predicate for testing whether the 'timeUnits' attribute of this Event is set.
    
    Returns:
    
    true if the 'timeUnits' attribute of this Event is set, false otherwise.
    
    "Warning:"
    
    Definitions of Event in SBML Level 2 Versions 1 and 2 included the additional attribute called 'timeUnits', but it was removed in SBML Level 2 Version 3. LibSBML supports this attribute for compatibility with previous versions of SBML Level 2, but its use is discouraged since models in Level 2 Versions 3 and 4 cannot contain it. If a Version 3 or 4 model sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
  - isSetUseValuesFromTriggerTime
```
public boolean isSetUseValuesFromTriggerTime()
```
    Predicate for testing whether the 'useValuesFromTriggerTime' attribute of this Event is set.
    
    Returns:
    
    true if the 'useValuesFromTriggerTime' attribute of this Event is set, false otherwise.
    
    "Note:"
    
    In SBML Level 2, this attribute is optional and has a default value of true, whereas in Level 3 Version 1, this optional is mandatory and has no default value.
  - setId
```
public int setId(java.lang.String sid)
```
    Sets the value of the 'id' attribute of this Event.
    The string sid is copied.
    
    SBML has strict requirements for the syntax of identifiers, that is, the values of the 'id' attribute present on most types of SBML objects. The following is a summary of the definition of the SBML identifier type SId, which defines the permitted syntax of identifiers. We express the syntax using an extended form of BNF notation:
```
 letter .= 'a'..'z','A'..'Z'
 digit  .= '0'..'9'
 idChar .= letter | digit | '_'
 SId    .= ( letter | '_' ) idChar*
```
    The characters ( and ) are used for grouping, the character * 'zero or more times', and the character | indicates logical 'or'. The equality of SBML identifiers is determined by an exact character sequence match i.e., comparisons must be performed in a case-sensitive manner. In addition, there are a few conditions for the uniqueness of identifiers in an SBML model. Please consult the SBML specifications for the exact details of the uniqueness requirements.
    Overrides:
    
    setId in class SBase
    
    Parameters:
    
    sid - the string to use as the identifier of this Event
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_INVALID_ATTRIBUTE_VALUE
  - setName
```
public int setName(java.lang.String name)
```
    Sets the value of the 'name' attribute of this Event.
    The string in name is copied.
    Overrides:
    
    setName in class SBase
    
    Parameters:
    
    name - the new name for the Event
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_INVALID_ATTRIBUTE_VALUE
  - setTrigger
```
public int setTrigger(Trigger trigger)
```
    Sets the trigger definition of this Event to a copy of the given Trigger object instance.
    Parameters:
    
    trigger - the Trigger object instance to use.
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_LEVEL_MISMATCH
    LIBSBML_VERSION_MISMATCH
  - setDelay
```
public int setDelay(Delay delay)
```
    Sets the delay definition of this Event to a copy of the given Delay object instance.
    Parameters:
    
    delay - the Delay object instance to use
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_LEVEL_MISMATCH
    LIBSBML_VERSION_MISMATCH
  - setPriority
```
public int setPriority(Priority priority)
```
    (SBML Level 3 only) Sets the priority definition of this Event to a copy of the given Priority object instance.
    Parameters:
    
    priority - the Priority object instance to use
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_LEVEL_MISMATCH
    LIBSBML_VERSION_MISMATCH
    LIBSBML_UNEXPECTED_ATTRIBUTE
    "Note:"
    
    The element 'priority' is available in SBML Level 3 Version 1 Core, but is not present in lower Levels of SBML.
  - setTimeUnits
```
public int setTimeUnits(java.lang.String sid)
```
    Sets the 'timeUnits' attribute of this Event to a copy of sid.
    Parameters:
    
    sid - the identifier of the time units to use.
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_INVALID_ATTRIBUTE_VALUE
    LIBSBML_UNEXPECTED_ATTRIBUTE
    "Warning:"
    
    Definitions of Event in SBML Level 2 Versions 1 and 2 included the additional attribute called 'timeUnits', but it was removed in SBML Level 2 Version 3. LibSBML supports this attribute for compatibility with previous versions of SBML Level 2, but its use is discouraged since models in Level 2 Versions 3 and 4 cannot contain it. If a Version 3 or 4 model sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
  - setUseValuesFromTriggerTime
```
public int setUseValuesFromTriggerTime(boolean value)
```
    Sets the 'useValuesFromTriggerTime' attribute of this Event to a value.
    
    The optional Delay on Event means there are two times to consider when computing the results of an event: the time at which the event is triggered, and the time at which assignments are executed. It is also possible to distinguish between the time at which the EventAssignment's expression is calculated, and the time at which the assignment is made: the expression could be evaluated at the same time the assignments are performed, i.e., when the event is executed, but it could also be defined to be evaluated at the time the event is triggered.
    In SBML Level 2 versions prior to Version 4, the semantics of Event time delays were defined such that the expressions in the event's assignments were always evaluated at the time the event was triggered. This definition made it difficult to define an event whose assignment formulas were meant to be evaluated at the time the event was executed (i.e., after the time period defined by the value of the Delay element). In SBML Level 2 Version 4, the attribute 'useValuesFromTriggerTime' on Event allows a model to indicate the time at which the event's assignments are intended to be evaluated. In SBML Level 2, the attribute has a default value of true, which corresponds to the interpretation of event assignments prior to Version 4: the values of the assignment formulas are computed at the moment the event is triggered, not after the delay. If 'useValuesFromTriggerTime'=false, it means that the formulas in the event's assignments are to be computed after the delay, at the time the event is executed. In SBML Level 3, the attribute is mandatory, not optional, and all events must specify a value for it.
    Parameters:
    
    value - the value of useValuesFromTriggerTime to use.
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_UNEXPECTED_ATTRIBUTE
    "Warning:"
    
    The attribute 'useValuesFromTriggerTime' was introduced in SBML Level 2 Version 4. It is not valid in models defined using SBML Level 2 versions prior to Version 4. If a Level 2 Version 1&ndash3 model sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
  - unsetId
```
public int unsetId()
```
    Unsets the value of the 'id' attribute of this Event.
    Overrides:
    
    unsetId in class SBase
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_OPERATION_FAILED
  - unsetName
```
public int unsetName()
```
    Unsets the value of the 'name' attribute of this Event.
    Overrides:
    
    unsetName in class SBase
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_OPERATION_FAILED
  - unsetUseValuesFromTriggerTime
```
public int unsetUseValuesFromTriggerTime()
```
    Unsets the value of the 'useValuesFromTriggerTime' attribute of this Event.
    
    The optional Delay on Event means there are two times to consider when computing the results of an event: the time at which the event is triggered, and the time at which assignments are executed. It is also possible to distinguish between the time at which the EventAssignment's expression is calculated, and the time at which the assignment is made: the expression could be evaluated at the same time the assignments are performed, i.e., when the event is executed, but it could also be defined to be evaluated at the time the event is triggered.
    In SBML Level 2 versions prior to Version 4, the semantics of Event time delays were defined such that the expressions in the event's assignments were always evaluated at the time the event was triggered. This definition made it difficult to define an event whose assignment formulas were meant to be evaluated at the time the event was executed (i.e., after the time period defined by the value of the Delay element). In SBML Level 2 Version 4, the attribute 'useValuesFromTriggerTime' on Event allows a model to indicate the time at which the event's assignments are intended to be evaluated. In SBML Level 2, the attribute has a default value of true, which corresponds to the interpretation of event assignments prior to Version 4: the values of the assignment formulas are computed at the moment the event is triggered, not after the delay. If 'useValuesFromTriggerTime'=false, it means that the formulas in the event's assignments are to be computed after the delay, at the time the event is executed. In SBML Level 3, the attribute is mandatory, not optional, and all events must specify a value for it.
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_OPERATION_FAILED
    "Warning:"
    
    The attribute 'useValuesFromTriggerTime' was introduced in SBML Level 2 Version 4. It is not valid in models defined using SBML Level 2 versions prior to Version 4. If a Level 2 Version 1&ndash3 model sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
  - unsetDelay
```
public int unsetDelay()
```
    Unsets the Delay of this Event.
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_OPERATION_FAILED
  - unsetPriority
```
public int unsetPriority()
```
    (SBML Level 3 only) Unsets the Priority of this Event.
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_OPERATION_FAILED
    "Note:"
    
    The element 'priority' is available in SBML Level 3 Version 1 Core, but is not present in lower Levels of SBML.
  - unsetTrigger
```
public int unsetTrigger()
```
    Unsets the Trigger of this Event.
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_OPERATION_FAILED
    "Note:"
    
    The element 'priority' is available in SBML Level 3 Version 1 Core, but is not present in lower Levels of SBML.
  - unsetTimeUnits
```
public int unsetTimeUnits()
```
    Unsets the 'timeUnits' attribute of this Event.
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_UNEXPECTED_ATTRIBUTE
    LIBSBML_OPERATION_FAILED
    "Warning:"
    
    Definitions of Event in SBML Level 2 Versions 1 and 2 included the additional attribute called 'timeUnits', but it was removed in SBML Level 2 Version 3. LibSBML supports this attribute for compatibility with previous versions of SBML Level 2, but its use is discouraged since models in Level 2 Versions 3 and 4 cannot contain it. If a Version 3 or 4 model sets the attribute, the consistency-checking method SBMLDocument.checkConsistency() will report an error.
  - addEventAssignment
```
public int addEventAssignment(EventAssignment ea)
```
    Appends a copy of the given EventAssignment to this Event.
    Parameters:
    
    ea - the EventAssignment object to add.
    
    Returns:
    integer value indicating success/failure of the function. The possible values returned by this function are:
    
    LIBSBML_OPERATION_SUCCESS
    LIBSBML_LEVEL_MISMATCH
    LIBSBML_VERSION_MISMATCH
    LIBSBML_DUPLICATE_OBJECT_ID
    LIBSBML_OPERATION_FAILED
    See Also:
    
    Event.createEventAssignment()
    
    "Note:"
    
    This method should be used with some caution. The fact that this method copies the object passed to it means that the caller will be left holding a physically different object instance than the one contained inside this object. Changes made to the original object instance (such as resetting attribute values) will not affect the instance in this object. In addition, the caller should make sure to free the original object if it is no longer being used, or else a memory leak will result. Please see other methods on this class (particularly a corresponding method whose name begins with the word create) for alternatives that do not lead to these issues.
  - createEventAssignment
```
public EventAssignment createEventAssignment()
```
    Creates a new, empty EventAssignment, adds it to this Event's list of event assignments and returns the EventAssignment.
    
    Returns:
    
    the newly created EventAssignment object instance
    
    See Also:
    
    Event.addEventAssignment(EventAssignment ea)
  - createTrigger
```
public Trigger createTrigger()
```
    Creates a new, empty Trigger, adds it to this Event and returns the Trigger.
    
    Returns:
    
    the newly created Trigger object instance
  - createDelay
```
public Delay createDelay()
```
    Creates a new, empty Delay, adds it to this Event and returns the Delay.
    
    Returns:
    
    the newly created Delay object instance
  - createPriority
```
public Priority createPriority()
```
    (SBML Level 3 only) Creates a new, empty Priority, adds it to this Event and returns the Priority.
    
    Returns:
    
    the newly created Priority object instance
    
    "Note:"
    
    The element 'priority' is available in SBML Level 3 Version 1 Core, but is not present in lower Levels of SBML.
  - getListOfEventAssignments
```
public ListOfEventAssignments getListOfEventAssignments()
```
    Returns the list of event assignments for this Event.
    
    Returns:
    
    the list of EventAssignments for this Event.
  - getEventAssignment
```
public EventAssignment getEventAssignment(long n)
```
    Return a specific EventAssignment object of this Event.
    
    Parameters:
    
    n - an integer, the index of the EventAssignment object to return
    
    Returns:
    
    the nth EventAssignment of this Event.
  - getEventAssignment
```
public EventAssignment getEventAssignment(java.lang.String variable)
```
    Return the event assignment indicated by the given variable.
    
    Parameters:
    
    variable - a string, the identifier of the variable whose EventAssignment is being sought.
    
    Returns:
    
    the EventAssignment for the given variable, or null if no such EventAssignment exits.
  - getNumEventAssignments
```
public long getNumEventAssignments()
```
    Returns the number of EventAssignment objects attached to this Event.
    
    Returns:
    
    the number of EventAssignments in this Event.
  - removeEventAssignment
```
public EventAssignment removeEventAssignment(long n)
```
    Removes the nth EventAssignment object from this Event object and returns a pointer to it.
    The caller owns the returned object and is responsible for deleting it.
    
    Parameters:
    
    n - the index of the EventAssignment object to remove
    
    Returns:
    
    the EventAssignment object removed. As mentioned above, the caller owns the returned item. null is returned if the given index is out of range.
  - removeEventAssignment
```
public EventAssignment removeEventAssignment(java.lang.String variable)
```
    Removes the EventAssignment object with the given 'variable' attribute from this Event object and returns a pointer to it.
    The caller owns the returned object and is responsible for deleting it. If none of the EventAssignment objects in this Event object have the 'variable' attribute variable, then null is returned.
    
    Parameters:
    
    variable - the 'variable' attribute of the EventAssignment object to remove
    
    Returns:
    
    the EventAssignment object removed. As mentioned above, the caller owns the returned object. null is returned if no EventAssignment object with the 'variable' attribute exists in this Event object.
  - connectToChild
```
public void connectToChild()
```
    Overrides:
    
    connectToChild in class SBase
  - getTypeCode
```
public int getTypeCode()
```
    Returns the libSBML type code of this object instance.
    
    LibSBML attaches an identifying code to every kind of SBML object. These are integer constants known as SBML type codes. The names of all the codes begin with the characters SBML_. In the Java language interface for libSBML, the type codes are defined as static integer constants in the interface class libsbmlConstants. Note that different Level 3 package plug-ins may use overlapping type codes to identify the package to which a given object belongs, call the getPackageName() method on the object.
    
    Overrides:
    
    getTypeCode in class SBase
    
    Returns:
    
    the SBML type code for this object: SBML_EVENT (default).
    
    See Also:
    
    Event.getElementName(), SBase.getPackageName()
    
    "Warning:"
    
    The specific integer values of the possible type codes may be reused by different Level 3 package plug-ins. Thus, to identifiy the correct code, it is necessary to invoke both getTypeCode() and getPackageName().
  - getElementName
```
public java.lang.String getElementName()
```
    Returns the XML element name of this object, which for Event, is always 'event'.
    
    Overrides:
    
    getElementName in class SBase
    
    Returns:
    
    the name of this element, i.e., 'event'.
  - hasRequiredAttributes
```
public boolean hasRequiredAttributes()
```
    Predicate returning true if all the required attributes for this Event object have been set.
    The required attributes for an Event object are:
    - 'useValuesfromTriggerTime' (required in SBML Level 3)
    Overrides:
    
    hasRequiredAttributes in class SBase
    
    Returns:
    
    true if the required attributes have been set, false otherwise.
  - hasRequiredElements
```
public boolean hasRequiredElements()
```
    Predicate returning true if all the required elements for this Event object have been set.
    Overrides:
    
    hasRequiredElements in class SBase
    
    "Note:"
    The required elements for an Event object are:
    
    'trigger'
    'listOfEventAssignments' (required in SBML Level 2, optional in Level 3)

Class Event

SBML Level/Version differences

SBML Level 3

SBML Level 2

Semantics of events in SBML Level 3 Version 1

Constructor Summary

Method Summary

Methods inherited from class org.sbml.libsbml.SBase

Methods inherited from class java.lang.Object

Constructor Detail

Event

Event

Event

Method Detail

delete

cloneObject

initDefaults

getElementBySId

getElementByMetaId

getId

getName

getTrigger

getDelay

getPriority

getTimeUnits

getUseValuesFromTriggerTime

isSetId

isSetName

isSetTrigger

isSetDelay

isSetPriority

isSetTimeUnits

isSetUseValuesFromTriggerTime

setId

setName

setTrigger

setDelay

setPriority

setTimeUnits

setUseValuesFromTriggerTime

unsetId

unsetName

unsetUseValuesFromTriggerTime

unsetDelay

unsetPriority

unsetTrigger

unsetTimeUnits

addEventAssignment

createEventAssignment

createTrigger

createDelay

createPriority

getListOfEventAssignments

getEventAssignment

getEventAssignment

getNumEventAssignments

removeEventAssignment

removeEventAssignment

connectToChild

getTypeCode

getElementName

hasRequiredAttributes

hasRequiredElements