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The <simpleAction> Element
Definition and Usage
The <simpleAction> element defines a simple action triggered by the evaluation of a causal relationship condition.
The <simpleAction> element has a role attribute, whose value must be unique in the connector’s role set. A role is a connector interface point, which is associated to node interfaces by a link that refers to the connector.
A <simpleAction> also defines an event type (eventType attribute) and which action must be applied to the event state machine it refers (actionType attribute). The eventType and actionType values may be inferred by the role value if reserved words are used as values. Otherwise, the eventType and actionType attributes are required.
Reserved action role values associated to event state machines:
| Role Value | Action Type | Event Type |
|---|---|---|
| start | start | presentation |
| stop | stop | presentation |
| abort | abort | presentation |
| pause | pause | presentation |
| resume | resume | presentation |
| set | start | attribution |
If an eventType value is “attribution”, the <simpleAction>must also define the value to be assigned, through its value attribute. If the value is specified as “$anyName” (where “$” is a reserved symbol and “anyName” is any string, except reserved role names), the assigned value is retrieved from the property associated with the role “anyName” and defined by a <bind> child element of the <link> element that refers the connector. If this value cannot be retrieved, no attribution is made. This is the single possible case of a <bind> element referring to a role that is not explicitly declared in a connector.
The role cardinality specifies the minimal (min attribute) and maximal (max attribute) number of participants that may play the role (that is, the number of binds) when the <causalConnector> is used for creating a <link>. If the max value is greater than one, the qualifier attribute may be specified informing the logical relationship among the simple action binds: “par” or “seq”. When the sequential “seq” qualifier is used, actions must be fired in the specified order. However, an action does not need to wait the previous one to be finished in order to be fired. When the parallel “par” qualifier is used, actions can be performed in any order.
A delay attribute may also be defined for a <simpleAction>, specifying that the action must be fired only after waiting for the specified time.
The <simpleAction> may also define a repeat attribute to be assigned to the repetitions attribute of the event, and a repeatDelay to be waited before repeating the action.
The <simpleAction> element may also define the duration and by attributes if its eventType value is “attribution” and only if the referred property defines numerical values or colors. When setting a new value to a property the change is instantaneous by default (duration is 0), but the change may also be carried out during an explicitly declared duration, specified by the duration attribute. The change from the old value to the new one may be linear by default (by is “indefinite”), or carried out step by step, with the pace specified by the by attribute.
Syntax
| Element | Attributes | Content | Parent |
|---|---|---|---|
| <simpleAction> | role, delay, eventType, actionType, value, min, max, qualifier, repeat, repeatDelay, duration, by | – | <causalConnector> or <compoundAction> |
Attributes
| Name | Value | Description |
|---|---|---|
| role | String. | The role attribute defines a connector interface point, which is associated to node interfaces by a link that refers to the connector. The role value must be unique within the set of roles of the connector. |
| delay | The delay attribute is be specified according with one of the following syntax:
The default value is “0s”. | The delay attribute defines a time delay to be awaited before triggering the action. |
| eventType | “presentation”, “selection”, or “attribution”. | The eventType attribute identifies the type of event for the action or condition. |
| actionType | “start”, “stop”, “abort”, “pause”, or “resume”. | The actionType attribute specifies the action to trigger the corresponding transition in the event state machine of the referred event. |
| value | String | The value attribute defines a value to be set to the property bound to the attribution simple action. |
| min | Positive integer lesser than or equal to the max value. The default value is 1. | The min attribute defines the minimum number of participants that may play the role. |
| max | Positive integer greater than or equal to the min value, or the “unbounded” value. The default value is 1. | The max attribute defines the maximum number of participants that may play the role. |
| qualifier | “seq” or “par”. The default value is “par”. | The qualifier attribute defines the order that actions must be applied in the simple action binds. |
| repeat | Positive integer. The default value is 0 | The repeat attribute defines a value to be assigned to the repetitions attribute of the event defined in the <simpleAction> element. |
| repeatDelay | Same as for delay. | The repeatDelay attribute specifies a time interval to be waited before repeating the action. |
| duration | The duration attribute is specified as Seconds“s”, where “Seconds” is a positive real number. | The duration attribute establishes the time an attribution must last when changing from the old value to the new one. |
| by | A real number or “indefinite”. The default value is “indefinite”. | The by attribute establishes how the change made by an attribution action from an old value to the new one occurs: if linearly (by is “indefinite”) or carried out step-by-step, with the pace specified by the by attribute. |