[Laszlo-dev] For Review: Change 20070806-maxcarlson-x Summary: Remove setter for LzNode.data

[Max Carlson]

 From my email on Friday:
 > Per the call this afternoon (and as signed off by David) we will add a
 > new method to LzNode called setData().
 >
 > LzNode.setData(dataelement) is called by the replicator immediately
 > after the .data property is set and ondata is sent, but before
 > applyData() is called on the node being replicated.  By default,
 > setData() creates a new datapath for the replicated view (if one doesn't
 > already exist) and it always sets the view datapath to the new
 > dataelement passed in.
 >
 > This approach allows replicated views to use $path expressions and
 > support datapath bindings out of the box.  setData() can still be
 > overridden on an instance or subclass of node to do something more
 > efficient (like read the data directly and set attributes).

I didn't expect a setter to be added.  I thought we'd just add the 
setData() method to LzNode and follow the contract above.  The change I 
made to replicator now does this.

After looking closer at what LzDatapath does now, maybe setData() should 
be emulating the behavior of LzDatapath.__LZApplyData().  Do you think 
some or all of LzDatapath.__LZApplyData() should be hoisted up to LzNode 
(instead of applyData)?

P T Withington wrote:
> I guess I am confused.  It seems that if you have a datapath (which any 
> node can?) then you might have your data attribute set and your 
> applyData method will be called.  If you don't have a datapath, you can 
> feel free to have a data attribute and it will not be mucked with.
> 
> Your solution to the issue of how replicators set the data context of 
> their children of last week was that they would set the data attribute 
> and that we would have a setter for node that would coerce that into a 
> data context.
> 
> We discovered that is no good, because there are subclasses of node that 
> expect to be able to have a data attribute -- so a general setter on 
> data is not going to fly.  This is too bad, because it seems the more 
> LZX-y thing to do would be to get rid of applyData and only have a 
> setter on data.
> 
> Instead, it looks like what we should do is hoist applyData up to node 
> and use that pattern.  <sigh>
> 
> On 2007-08-06, at 19:49 EDT, Max Carlson wrote:
> 
>> Which behavior did you hoist up from text?  The only difference 
>> between LzText and LaszloView I see is the implementation of applyData().
>>
>> It looks to me like .data is set in LzDatapath.__LZApplyData(). 
>> LzDatapath.__LZHandleDocChange() also appears on .data being set.
>>
>>
>>
>> P T Withington wrote:
>>> FTR,
>>> The problem is that we hoisted data up from text to node, but 
>>> databinder (a subclass of node) already defined a data attribute.  As 
>>> Max points out, it would be nice to have consistent behavior for the 
>>> meaning of the data attribute on nodes.
>>> Some alternatives:
>>> 1) Make data a reserved property of node, fix all subclasses of node 
>>> to deal with that.
>>> 2) Use a different name for this property, fix text to use that 
>>> different name.
>>> 3) Only hoist data up to view, since replicators only replicate views.
>>> Other ideas?
>>> On 2007-08-06, at 17:46 EDT, Pablo Kang wrote:
>>>> Looks good. Adding a comment why setData isn't a setter for the data 
>>>> attribute would help. Alternatively, rename setData to something 
>>>> else and comment what that method does exactly. In particular, how 
>>>> it creates a datapath if one doesn't already exist.
>>>>
>>>> pablo
>>>>
>>>> On Mon, 6 Aug 2007, Max Carlson wrote:
>>>>
>>>>> Change 20070806-maxcarlson-x by maxcarlson at plastik on 2007-08-06 
>>>>> 14:30:15 PDT
>>>>>   in /Users/maxcarlson/openlaszlo/wafflecone
>>>>>   for http://svn.openlaszlo.org/openlaszlo/branches/wafflecone
>>>>>
>>>>> Summary: Remove setter for LzNode.data
>>>>>
>>>>> New Features:
>>>>>
>>>>> Bugs Fixed: LPP-4405 'Implement ExplicitReplication' (partial)
>>>>>
>>>>> Technical Reviewer: promanik
>>>>> QA Reviewer: ptw, pkang
>>>>> Doc Reviewer: (pending)
>>>>>
>>>>> Documentation:
>>>>>
>>>>> Release Notes:
>>>>>
>>>>> Details: LzNode.lzs - Remove setter for .data -> setData().
>>>>>
>>>>> replicator.lzx - Call v.setData( this.nodes[ n ] ); instead of 
>>>>> setAttribute('data', ...)
>>>>>
>>>>>
>>>>> Tests: silver/main.lzx?lzr=swf8 runs again, 
>>>>> http://localhost:8080/wafflecone/test/explicit-replicators/replicator.lzx?lzr=swf8 
>>>>> passes
>>>>>
>>>>> Files:
>>>>> M      WEB-INF/lps/lfc/core/LzNode.lzs
>>>>> M      lps/components/utils/replicator/replicator.lzx
>>>>>
>>>>> Changeset: 
>>>>> http://svn.openlaszlo.org/openlaszlo/patches/20070806-maxcarlson-x.tar
>>
>> -- 
>> Regards,
>> Max Carlson
>> OpenLaszlo.org
> 

-- 
Regards,
Max Carlson
OpenLaszlo.org