- From: Gavin Kistner <phrogz@me.com>
- Date: Tue, 12 Feb 2013 19:45:58 -0700
- To: "www-voice@w3.org" <www-voice@w3.org>
I believe that this pseudo-code from the top oc addStatesToEnter() is incorrect: if isHistoryState(state): if historyValue[state.id]: for s in historyValue[state.id]: addStatesToEnter(s,statesToEnter,statesForDefaultEntry) for anc in getProperAncestors(s,state): statesToEnter.add(anc) Specifically, the second-to-last line. The proper ancestors of the states recorded by a <history> will never include the <history> itself (noted by "state" above), and so the line is equivalent to calling `getProperAncestors(s,null)`. Consequently, every ancestor of a recorded node is added to the entry set, *including the root <scxml> node itself*. Here's a simple example machine: <scxml xmlns="http://www.w3.org/2005/07/scxml" version="1.0" name="HistoryTest"> <initial><transition target="universe"> <raise event="modal.on" /> <raise event="modal.off" /> </transition></initial> <state id="universe"> <transition event="modal.on" target="modal" /> <state id="s1" /> <history id="h"><transition target="s1"/></history> </state> <state id="modal"><transition event="modal.off" target="h"/></state> </scxml> The machine enters 'universe/s1', then exits these states (recording 's1' in the history for 'h') and enters 'modal'. When the machine processes the 'modal.off' event, enterStates() calls addStatesToEnter(), passing along the <history> node. I believe that the second-to-last line in the quoted code above should perhaps instead read: for anc in getProperAncestors(s,state.parent):
Received on Wednesday, 13 February 2013 02:46:35 UTC