[Laszlo-dev] datasets and XML namespace support

[Max Carlson]

Yeah, make whitespace trimming default to false.  As long as people can 
turn it on again, I think it's the right choice.

-Max

Henry Minsky wrote:
> Speaking of which, the default behavior of the data compiler right now
> is to trim whitespace from the start and end of text content. I put
> that in way back when to provide back compatibility when it was needed
> in a hurry for the BEAM deliverable.
> 
> Should we change that to not trim whitespace by default? That would
> fix another incompatibility with SOLO data loading. There is a flag,
> trimwhitespace, but it defaults to true
> for proxied data loading, and is ignored in SOLO (text is never trimmed)
> 
> 
> 
> 
> On 9/12/05, Max Carlson <max at laszlosystems.com> wrote:
> 
>>One more vote for changing the default behavior - with a compatibility flag.
>>
>>-Max
>>
>>Henry Minsky wrote:
>>
>>>OK, that's one vote for changing the default behavior. Do I hear any others?
>>>
>>>
>>>On 9/12/05, P T Withington <ptw at pobox.com> wrote:
>>>
>>>
>>>>It seems to me that the stripping of namespaces is a bug that should
>>>>be fixed.  If there are apps that depend on that (mis) feature, you
>>>>could have a deprecated compatibility flag for one release.
>>>>
>>>>On 12 Sep 2005, at 12:43, Henry Minsky wrote:
>>>>
>>>>
>>>>
>>>>>I'm doing some design and implementation to add simple namespace
>>>>>support to the data APIs, and wanted to get some feedback from people
>>>>>on how they think things would work best.
>>>>>
>>>>>I'm a little surprised more people haven't run into this, but I guess
>>>>>SOLO deployment hasn't been out in the wild very long. The single bug
>>>>>report I have gotten so far was from someone trying to use an RSS feed
>>>>>in SOLO mode.
>>>>>
>>>>>
>>>>>Below is an excerpt from the bug I filed, and then some design
>>>>>proposals.
>>>>>
>>>>>
>>>>>Key: LPP-653
>>>>>       URL: http://www.openlaszlo.org/jira/browse/LPP-653
>>>>>   Project: OpenLaszlo
>>>>>      Type: Bug
>>>>>Components: Laszlo Foundation Classes - Data, Server - Data Transport
>>>>>  Reporter: Henry Minsky
>>>>>  Priority: --
>>>>>
>>>>>
>>>>>consider this XML data
>>>>>
>>>>>
>>>>><?xml version="1.0" encoding="UTF-8"?>
>>>>><rdf:RDF
>>>>>xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>>>>>xmlns="http://purl.org/rss/1.0/"
>>>>>xmlns:cc="http://web.resource.org/cc/"
>>>>>xmlns:taxo="http://purl.org/rss/1.0/modules/taxonomy/"
>>>>>xmlns:dc="http://purl.org/dc/elements/1.1/"
>>>>>xmlns:syn="http://purl.org/rss/1.0/modules/syndication/"
>>>>>xmlns:admin="http://webns.net/mvcb/"
>>>>>
>>>>>
>>>>>
>>>>>   <channel rdf:about="http://del.icio.us/gyardley">
>>>>>       <title>del.icio.us/gyardley</title>
>>>>>       <link>http://del.icio.us/gyardley</link>
>>>>>
>>>>>
>>>>>When loaded at runtime in SOLO mode, you get the XML basically as
>>>>>above, but proxied mode, the namespace prefixes are stripped off
>>>>>before the data is sent from the server, and the app sees
>>>>>
>>>>><RDF>
>>>>>   <channel about=\"http://del.icio.us/gyardley\">
>>>>>           <title>del.icio.us/gyardley</title>
>>>>>           <link>http://del.icio.us/gyardley</link>
>>>>>
>>>>>
>>>>>
>>>>>Aside from general problem losing the namespace prefixes, the
>>>>>developer cannot
>>>>>use the same XPath queries in SOLO and proxied mode, because
>>>>>element names
>>>>>(and attribute names) are different; "rdf:RDF" vs. "RDF", "rdf:about"
>>>>>vs. "about".
>>>>>
>>>>>
>>>>>
>>>>>+ Proposal:
>>>>>
>>>>>[A] add a "nsprefix" flag to <dataset>:
>>>>>
>>>>>   <dataset name="lds" src="namespace.xml" nsprefix="false"
>>>>>request="true" type="http" />
>>>>>
>>>>>when nsprefix=false, namespace prefixes are discarded from element and
>>>>>attribute names.
>>>>>
>>>>>
>>>>>   <dataset name="ldsns" src="namespace.xml" nsprefix="true"
>>>>>request="true" type="http" />
>>>>>
>>>>>when nsprefix=true, namespace prefixes are preserved on element and
>>>>>attribute names
>>>>>
>>>>>
>>>>>Currently, all data loads in SOLO mode act as if nsprefix=true, due to
>>>>>the Flash XML parser behavior, and all data loads in proxied mode acts
>>>>>as if nsprefix=false, because we've always done it that way.
>>>>>
>>>>>
>>>>>[B] I propose not supporting nsprefix=false in SOLO mode, for the
>>>>>time being
>>>>>
>>>>>It would be easy to write the string string frobbing code in the LFC
>>>>>to strip namespace prefixes from data nodes, in order to make it act
>>>>>like proxied data does now, but it seems to me that would be a
>>>>>performance hit that not many developers would want to choose, given
>>>>>how slow actionscript is already.
>>>>>
>>>>>[C] What should be done about compile-time inline data?
>>>>>
>>>>>If datasets are specified as filenames, the data is compiled into the
>>>>>app. In that case we have full control over what it looks like, in
>>>>>either SOLO or proxied mode:
>>>>>
>>>>>   <dataset name="localds" src="namespace.xml" nsprefix="false" />
>>>>>
>>>>>   <dataset name="localdsns" src="namespace.xml" nsprefix="true" />
>>>>>
>>>>>The question is what should the default setting of the nsprefix
>>>>>flag be?
>>>>>
>>>>>Should it remain false in both the SOLO and proxied case? Or should it
>>>>>default to true in the SOLO case, so that these cases return
>>>>>exactly the
>>>>>same values for node and attribute names in SOLO mode?
>>>>>
>>>>>
>>>>>   <dataset name="foo" src="namespace.xml" />         # inline
>>>>>
>>>>>   <dataset name="bar" src="namespace.xml"  type="http" /> # http
>>>>>runtime loaded
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>--
>>>>>Henry Minsky
>>>>>Software Architect
>>>>>hminsky at laszlosystems.com
>>>>>
>>>>>_______________________________________________
>>>>>Laszlo-dev mailing list
>>>>>Laszlo-dev at openlaszlo.org
>>>>>http://www.openlaszlo.org/mailman/listinfo/laszlo-dev
>>>>>
>>>>
>>>>
>>>
>>
> 
>