ECARule extends ConditionEdgeDestination, GeneratedElement, GeneratesElements, NamedElement, ParameterEdgeDestination

An ECARule defines how a triggering Event may execute a particular Action, as optionally restricted by incoming Conditions.

An ECARule specifies that a triggered Event will execute a specific Action if permitted to by any incoming Conditions. This ECARule may have incoming Parameters, which are passed by value at the time that the Event is triggered. This ECARule may also have incoming Conditions, which are evaluated at the time of the triggered Event; if these conditions are not true, then the Action will not be executed.

When an Event is triggered, all outgoing ECARules are sorted in descending order according to their integer property priority, and then evaluated in a sequential manner according to their incoming Predicates; this set is known as the current execution set. All executable ECARules are then followed sequentially in this order, and the type of action specified by the target Action are executed, until all ECARules are executed or an Action fails.

For an ECARule to be executable, all incoming Conditions must evaluate to true according to logical conjunction (AND). Conditions may be connectedissue 134 with a ConstraintEdge to change this behaviour to logical disjunction (OR) or exclusive disjunction (XOR). Any incoming Parameters to that ECARule are then calculated, and passed as named parameter values to the target Action.

[ECARule.html]

Examples

NavigateConditionWire.iaml (source)
- Using a SimpleCondition to control redirection access on a ECARule. [NavigateConditionWire]
NavigateWithParameter.iaml (source)
- A Parameter can connect to a ECARule in order toprovide named QueryParameters to the destination Frame. [NavigateWithParameter]

Implementation Notes

A failing operation within an ActivityOperation wrapped with a ECARulenamed 'fail' will redirect to the destination Frame instead. [testFailingOperation()]
If a ECARule is restricted by an incoming Condition, the redirection will be prevented if thesource Condition fails. [NavigateConditionWire]
An ECARule may be used to resume Frame accesspreviously limited by an entry Gate. [GateDisclaimer]
If an entry Gate is connected by an ECARule called "first",then the target Frame must be viewed at least once before proceeding. [GateRequiredPage]
If an exit Gate is connected by an ECARule called "last",then the target Frame must be viewed at least once before proceeding. [ExitGateAdSimple]
Any incoming named Parameters to a ECARule will bepassed along as named GET parameters to the destination Frame through QueryParameters. [NavigateWithParameter]
After a BuiltinOperation has completed, all outgoing ECARules are executed in order of priority. [ExecutionFlow]
An ECARule linking to a Frame or a Gate will implicitly be a navigation, rather than executing an Operation. [OperationCall]
Currently fail ECARules cannot handle additional incoming Parameters. [Failure]
Any incoming named Parameters to a ECARule to a Frame will be passed along as named GET parameters to the destination. [OperationCall]

Inference Rules

An input entry Gate will update the value of each input Label from the value of each similarly named VisibleThing in the input Frame when the protected Scope is accessed. [gate]
A Frame contained by a Session protected by a LoginHandler of type SECRET_KEY will execute the 'check key' Operation with a high priority when the frame is accessed. [login-handler]
If a LoginHandler has a defined outgoing ECARule named 'logout', then this rule should be executed after a successful 'do logout' ActivityOperation. [login-handler]
If a LoginHandler has an outgoing navigation rule named 'logout', then this navigation rule will be executed when the logout Frame is accessed. [login-handler]
If no 'logout' ECARule is defined for a LoginHandler, then the 'logout successful' Frame will be defined as the 'logout' ECARule. [login-handler]
If no 'success' ECARule is defined for a LoginHandler, then the 'login successful' Frame will be defined as the 'success' ECARule. [login-handler]
When the logout Frame for a LoginHandler is accessed, the 'do logout' Operation will be called. [login-handler]
All conditions against a SetWire will be copied to each ECARule subsequently created as connected to the onChange Events. [conditions]
All conditions against a SetWire will be copied to each ECARule subsequently created as connected to the onChange Events. [conditions]
All Parameters for each conditions against a SetWire will be copied to each SimpleCondition subsequently created for ECARules connected to the onAccess Events. [conditions]
All Parameters for each conditions against a SetWire will be copied to each SimpleCondition subsequently created for ECARules connected to the onChange Events. [conditions]
All conditions against a SyncWire will be copied to each ECARule subsequently created as connected to the onAccess Events. [conditions]
All conditions against a SyncWire will be copied to each ECARule subsequently created as connected to the onChange Events. [conditions]
All Parameters for each conditions against a SyncWire will be copied to each ECARule subsequently created as connected to the onAccess Events. [conditions]
All Parameters for each conditions against a SyncWire will be copied to each ECARule subsequently created as connected to the onChange Events. [conditions]

Constraints

"This ECA Rule will not do anything: consider naming it 'onClick'" [Checks.chk]
"Unknown outgoing ECARule '".+(name).+("' from this AccessControlHandler") [Checks.chk]
"Unknown outgoing ECARule '".+(name).+("' from this LoginHandler") [Checks.chk]
"An ECARule must have a 'target'" [Checks.chk]
"An ECARule must have a 'trigger'" [Checks.chk]
"A 'login' ECARule for an AccessControlHandler should not be in the same Scope as the handler; this will cause an infinite redirection, as the login page can never be accessed." [Checks.chk]

Attributes

priority : EInt (optional)
ECARules are executed in order of descending priority; that is, a higher priority ECARule will execute first.

Inherited Attributes

generatedRule : EString (optional)
To assist in debugging, this attribute may be populated with the name of the model completion rule that created this element. More extensive traceability support may be provided in the future.
id : EString (optional)
A unique identifier for this model element. Should be globally unique.
isGenerated : EBoolean (optional)
Set to true if the current element has been generated.
name : EString (optional)
A non-unique string that names a given object.
overridden : EBoolean (optional)
If a GeneratesElements is overridden, then this element will not generate any elements directly.
overriddenNames : EString (optional)
When applying model completion, no NamedElements with these names will be generated by this element.

Inherited Children

(none)

References

target : [1] Action [opposite: rules]
The target, or consequence, of the ECARule.
trigger : [1] ActionEdgeSource [opposite: listeners]
The source, or trigger, of the ECARule, normally an Event.

Inherited References

conditions : [0...*] ComplexTerm [opposite: conditioned]
A list of incoming Conditions that may restrict the behaviour of this element.
generatedBy : [0...*] GeneratesElements [opposite: generatedElements]
A list of elements that generated this element; conversely, overriding the source will prevent this element from being created.
generatedElements : [0...*] GeneratedElement [opposite: generatedBy]
A list of GeneratedElements that this element has generated through model completion.
inParameterEdges : [0...*] Parameter [opposite: parameterTerm]
A list of incoming Parameters.