Last Comment Bug 293571 - output not refreshed due to xpath dependency problem?
: output not refreshed due to xpath dependency problem?
: fixed1.8.0.4, fixed1.8.1
Product: Core Graveyard
Classification: Graveyard
Component: XForms (show other bugs)
: Trunk
: All All
P2 normal (vote)
: ---
Assigned To: Allan Beaufour
: Stephen Pride
Depends on:
Blocks: 326372 326373 332853
  Show dependency treegraph
Reported: 2005-05-10 01:08 PDT by aaronr
Modified: 2016-07-15 14:46 PDT (History)
3 users (show)
See Also:
QA Whiteboard:
Iteration: ---
Points: ---

testcase (1.31 KB, application/xhtml+xml)
2005-05-10 01:13 PDT, aaronr
no flags Details
Patch (7.90 KB, patch)
2006-03-27 08:16 PST, Allan Beaufour
doronr: review+
aaronr: review+
Details | Diff | Splinter Review

Description User image aaronr 2005-05-10 01:08:53 PDT
Well, I THINK that the summary is right.  I guess Allan will have to tell us if
I've gotten on the wrong track.  If I 'bind' an output to instance data element
using @value="/values/value[1]", the output control won't be refreshed if we do
a xf:setvalue with value="/values/value[1]".  However, if we change both
expressions to be "/values/value", then it will refresh fine.

Output elements don't end up with a mBoundNode since it calls ResetBoundNode
with type = nsIDOMXPathResult::STRING_TYPE instead of evaluating for a node when
it detects @value w/o other binding attributes.  So the output control will
depend on the xpath dependencies that come back during the call to
nsXFormsXPathAnalyzer::Analyze() (called during node binding) to detect when to
rebind and refresh when nsXFormsModelElement::Revalidate is called.  A
dependency node is found when "/values/value" is evaluated, but not when
"/values/value[1]" is called.  So that output control won't detect that it needs
to be refreshed after set value changes the instance node.

I think that I remember problems with output not refreshing correctly if bound
solely with @value but I couldn't find an open bug that seemed to match this.
Comment 1 User image aaronr 2005-05-10 01:13:37 PDT
Created attachment 183127 [details]

clicking on the trigger should update the output value from 10 to 20000
Comment 2 User image Allan Beaufour 2006-03-27 08:16:19 PST
Created attachment 216410 [details] [diff] [review]

Problem is that a @value expression has no bound node (because it is STRING_TYPE), so the normal logic of mBoundNode keeping a "reference" to the "single node result" of the XPath expression does not work.

This patch fixes this by letting the XPath Analyzer include the result, if the result type is of STRING_TYPE. This means that for output @value, the single node result is included in the dependencies list, and thus refreshed (rebound) correctly.

(it's been a while since I've ventured down in these files. Oh, are they undocumented, etc... ouch ouch)
Comment 3 User image Doron Rosenberg (IBM) 2006-03-27 08:32:14 PST
Comment on attachment 216410 [details] [diff] [review]

fixed the problem
Comment 4 User image Allan Beaufour 2006-03-28 23:54:46 PST
Checked into trunk

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