Transitions

A transition defines the change to the next skill when the current skill ends. Transitions get triggered by an event and link to a followup skill. This can be a useful tool to create, for example, loops or other kinds of control flow.

Within a skill_sequence, all skills already automatically transition to the next following skill.

Defined at file models/coordination.xml in package pitasc_library.

General structure

xml

Chain of prototype based inheritance

any_transition¹--> transition --> dictionary --> base --> descriptive

All transitions are inheriting from ‘transition’.

Transitions contain the following attributes inside the <type> tag.

Attributes inside <type> tag

Attribute	Description
id	Name of the transition, e.g. “my_transition”. Needs to be locally unique to allow identification. If not unique, a incrementing element e.g., “_no0”, “_no1”, “_no2”, … will be added
data_type	Already set by inheritance (dict)
prototype	The base type the transition “inherits” from, e.g. “transition”.

Transitions contain the following parameters inside the <meta> tag by default.

Members inside <meta> tag

Member	Description
description	Describes the transition
visibility	Visibility of the transition (one of: required, basic, expert, hidden)

Transitions contain the following parameters inside the <data> tag by default.

Members inside <data> tag

Member	Description
event	Name of the event that triggers the transition.
target	Id of the target skill (skill that gets transitioned to).

The xml definition of a transition basically looks like the following:

<type id= '{Choose unique id}' prototype= '{Add parent transition id}'> <!-- reference here -->
    <meta>
        <member id="description"> {Choose meaningful description} </member>
        <member id="visibility"> {Choose enum} </member>
    </meta>
    <data>
        <member id="event"> {Choose event name} </member>
        <member id="target"> {Choose target name} </member>
    </data>
</type>