dotnetrdf-develop — Developer Discussion and Feature Request

[dotNetRDF-Develop] Advance Notice of Breaking API Changes in Upcoming 0.4.1 Release

[Rob V. <rv...@do...>]

Hi All

Please take a look at our latest blog post - 
http://www.dotnetrdf.org/blogitem.asp?blogID=43 - which describes some 
breaking API changes we have made for the forthcoming release based on user 
feedback to address a key limitation of the API.

As stated in the blog post all your code should be easily fixable using a 
simple find and replace so while the change is fundamental in some respects 
from a code perspective it is relatively minor.

Apologies in advance for breaking your code when the new release comes out 
late next week.

Best Regards,

Rob Vesse

 

[dotNetRDF-Develop] Pending Merge of 0.4.1 Branch to Trunk

[Rob V. <rv...@do...>]

Hi all

It is planned that the 0.4.1 branch - which contains some important 
improvements but also some minor breaking changes - will be merged into the 
Trunk at the end of the week.

Anyone who is currently using 0.4.0 from SVN (i.e. the stable 0.4.0 release 
with some minor bug fixes) should ensure they have obtained a copy of the 
Trunk prior to this time.  On Friday the 0.4.1 branch will be merged and we 
will begin integration and regression testing on the core library with a 
view to preparing for the 0.4.1 release at the end of April.

As always if you have any questions please let me know,

Regards,

Rob Vesse

 

Re: [dotNetRDF-Develop] Question about dotNetRdf library

[Rob V. <rv...@do...>]

Hi Andres

I know you emailed me the other month and I tried to reply but your email servers rejected my attempts at responding - you can see my original responses at http://sourceforge.net/mailarchive/message.php?msg_id=27140153

With regards to Euler the .Net implementation is not dead it is called EulerSharp - http://sourceforge.net/projects/eulersharp/ - and is still developed by Jos De Roo
The reasoners in dotNetRDF are certainly less powerful than Euler, reasoning has never been a huge priority for us.  As a quick way to integrate the two libraries you could use Euler to do the reasoning and use the output is produces (which I assume is in N3 format) and parse that into dotNetRDF to use as you wish.

It is probably possible to port the Euler reasoner onto dotNetRDF's API model but I have no idea how much work this would entail, if you'd like to do this and contribute it back to the project that'd be great.

Regards,

Rob Vesse

----------------------------------------
From: "Andres Hohendahl" <an...@pb...>
Sent: 01 April 2011 02:31
To: rv...@do...
Subject: Question about dotNetRdf library 






Hi Rob 
Vesse 
  
I see you bave don a 
wonderful job with all the stuff on dotnet.org, 
congratulations! 
Hope one day I can 
have a depp understanding of all the standards and formats you included 
inside! 
  

My purpose is to 
make a simple reasoner for a NLP dialog SDK system I am building for the las 5 
years,  
The idea is get a system packed with huge owl/rdf 
ontologies spread in the wild, so it may rason, link names find relations etc. 
 
Making a semantic 
web reasoner for linking into a simple human-machine dialog + reasoner 
system. 
  
Have to confess I 
have not much RDF-N3 etc. knowledge, better than the triple notation the 
rules-ontology hierarchy and some idea of reasoning. 
Now I have some 
questions to make.  First I will intoduce you the elements that confused 
me. 
After seeing your 
library I saw another similar library called EulerDotNet, created by Jos Roo, 
from AGFA and member of the W3C 
This library claims 
to be the fastest N3/DRF reasoner because it's using a Prolog+Euler reasoner 
using a ultra-fast java to prolog interface, all contained inside a big jar 
container. 
This project also 
has a .NET implementation, but it seems to be abandoned sometime between 2005 
and 2006. 
  
I tried to link all 
this together because the Euler Reasoner works really fast! and allows many 
problems (classical Socrates and Einstein ones) to be solved in a 
glimps! 
he problem is that 
people like yuo and me and many more, do not document all the stuff, specially 
3-rd party libs and code-blocks, so I am really confused on the compatibility of 
all this systems. I see a Prolog reasnones is necessary to solve FOL (First 
Order Logic) and a fast and intelligent algorithm like Euler's one may be 
good to be used with huve triplets and rules stores, to achive something in real 
time (not academoc work). 
  
So the main question 
is ¿did you see this libs? is the resoner you iimplemented as good as their's 
(sorry, I cannot inferr it from the docs) As my limited idea, it is not as good 
as Euler, and aldo  I found a C# native Prolog calles Yield Prolog, which 
is embeddable inside a library and works as fast as the best Prolog (they 
claim), and all this may be tied up together to make a bertter library, I 
guess 
  
I lay up the 
threads to this ideas, may be good, may be wrong, you'll see and have the last 
word 
  
I can help a little 
to tie them together with my limited capabilities  
(I am a C#, Java, 
Pascal, etc. programmer since 8 years using C# under .NET, written over 600k 
lines of code .. that is working...!). 
  
best 
regards. 
  
 



  
  
    
      Andrés T. 
      Hohendahl	 
      CEO 
      – director	 
      	 
      (	 
      Office:+54 11 
      4711-9358	 
      )	 
      Mobile: +54 9 11 (15) 
      4148-1728	 
      *	 
      an...@pa...	 
      :	 
      www.pandorabox.com.ar	 


 

Re: [dotNetRDF-develop] Suggestion / Question about Euler-type reasoners and integration to other open projects

[Rob V. <rv...@do...>]

Hi Andres

I honestly don't know how easy it would be to do any of the integration and in some ways I'd rather do new implementations of things from scratch rather than trying to merge and shoehorn external code into our library.
As you'll see from our ideas page [1] we have various reasoning projects planned but no time to do them for the time being.

With regards to Euler I'm not sure how easy it would be to implement for dotNetRDF as I have never looked in detail at how the reasoning algorithm works.

As of our latest release (out today) we do support simple N3 rules of the following form:

{ ?x a ex:Car } => { ?x a ex:Vehicle }

To use these you can use the SimpleN3RulesReasoner [2] found under VDS.RDF.Query.Inference

If you really need/want Euler reasoning that I suggest talking to Jos de Roo about how his algorithm works and consider trying to implement it yourself using the dotNetRDF API and submitting it as a contribution to the project.

I see no value in merging SemWeb with dotNetRDF as there are few features it provides which we don't already have and/or do better.  If you disagree please let me know which feature from it you'd like to see in dotNetRDF and we can discuss whether that is feasible.

As for OWL reasoning none of these libraries (including dotNetRDF) support any form of OWL reasoning currently.  Like I say we plan on adding it in the future but can't give you any indication of timescale for this.

If your OWL reasoning needs are covered by Pellet and you can have all the data externally in a Pellet Server instance then you can use our built in Pellet Server client [3] to access some features of Pellet from within dotNetRDF.

Regards,

Rob Vesse

[1] http://www.dotnetrdf.org/content.asp?pageID=Ideas
[2] http://www.dotnetrdf.org/api/index.asp?Topic=VDS.RDF.Query.Inference.SimpleN3RulesReasoner
[3] http://www.dotnetrdf.org/api/index.asp?Topic=VDS.RDF.Query.Inference.Pellet.PelletServer

----------------------------------------
From: "Andres Hohendahl" <and...@gm...>
Sent: 01 March 2011 21:58
To: rv...@do...
Subject: Suggestion / Question about Euler-type reasoners and integration to other open projects 






Hello 
  
I have been 
searching on C# W3C-RDF/N3 libraries, and found yours, which appears 
to be very good, full, well fomatted and somehow extensible. 
I also found many 
truncated words like this 
http://eulersharp.sourceforge.net/
which claims to have 
a vert fast reasoner, but only a poor parser/object 
interfase. 
I tested it but the 
information is bad-formatted and difficult to understand, compiled and made a 
lot aof demonstrations, many of which dont work as claimed!. 
...but the reasoner 
works fine at least with simple deductions and samples. 
  
also found this 
one: 
SemWeb: A Semantic 
Web Library for 
C#/.NET
========================================== 
 
By Joshua Tauberer 
<http://razor.occams.info> 
 
http://razor.occams.info/code/semweb 
The code seems to be 
abandoned!  
  
and it seems to be 
fine, also well formatted and full of good-samples, but lacks a 
reasoner 
(only blame: its 
slow, because it don''t use .NET2.0 faster classes, and still hangs with 
ArrayList() instances and some nasty enumeratos, because the code is mostly 
ported from Java2 with an automatic converter)  
Also here: the code 
seems to be abandoned! 
  
  
So my questions 
are: 
  
I am developing an 
AI-dialog description language, with a runtime and a real compiler, for active 
and intelligent agents creation. 
I use reasoners in 
the old-way (neural nets, learners, bayesian inference engines, 
etc.) 
I found those 
AI-stuff work well but there is a lot more of knowledge out there, hidden in a 
bunch of standards, spread in differents databases and 
websites. 
I want to implement 
some W3C standard interoperative semantic-oriented tasks, mainly ontology 
reasoning for a NLP Query-Answering system 
I want to integrate 
wordnet and own ontologies also as an active ontology for 
reaoning. 
I want them to 
interact and reason with OWL FOAF KIT and other ontologies + 
operators. 
Is there a chace to 
merge the projects, they are separatedly very good but joined they will be 
greath,  
I may (if I can) 
help to manage this, with the permission of all of you! 
  
  
thanks 
  
 



  
  
    
      Andrés T. 
      Hohendahl	 
      CEO 
      – director	 
      	 
      (	 
      Office:+54 11 
      4711-9358	 
      )	 
      Mobile: +54 9 11 (15) 
      4148-1728	 
      *	 
      an...@pa...	 
      :	 
      www.pandorabox.com.ar	 


  

[dotNetRDF-develop] dotNetRDF 0.4.0 Beta Released

[Rob V. <rv...@do...>]

Hi all

The new release of dotNetRDF is now available.  The new version is 0.4.0 
and is our first official Beta release.  Below is a quick summary of new 
features, you can read more online at 
http://www.dotnetrdf.org/blogitem.asp?blogID=40 or see the full Change Log 
in the download package.

Key New Features/Improvements
- Much improved SPARQL 1.1 support for both Query and Update
- Graph Difference calculation
- Convert/Cast Graphs and SPARQL Result Sets into DataTables
- Support for simple N3 rules
- Some internal restructuring to improve performance and extensibility
- Various bug fixes for 0.3.1 issues

As a major release this does make some breaking API changes but mostly to 
things that were only used internally.  If you have any issues when 
upgrading please get in touch.

You may experience some minor differences in SPARQL evaluation due to fixes 
to both fixes/improvements in our engine and changes made to make our 
implementation meet the specification better where the official test suites 
indicated our implementation was incorrect.

We strongly recommend you upgrade to the latest version ASAP
- http://www.dotnetrdf.org/content.asp?pageID=Download%20dotNetRDF
- 
http://sourceforge.net/projects/dotnetrdf/files/Library/0.4.0%20Beta/dotnetr
df_library_040_beta.zip/download

Best Regards,

Rob Vesse

 

[dotNetRDF-develop] Proposed Deprecation of SQL Stores in future releases

[Rob V. <rv...@do...>]

Hi All

I wanted to make everyone aware that it is my intention to mark all the SQL 
Stores and their related classes as obsolete in the next release (0.4.0 
Beta) of dotNetRDF.  They will still be usable for the next few versions 
(most likely until the 0.5.x releases which will be late 2011 at the 
earliest) in their current forms. I am not necessarily going to remove SQL 
stores in their entirety but I would like to significantly restructure the 
existing code.  It is likely that I will start from scratch and just 
re-implement support as IGenericIOManager implementations.  It is very 
likely that the existing ISqlIOManager interface will be removed form the 
library completely.

I am not yet sure whether I will modify the actual database structure or 
not though if I do so I will provide upgrade mechanisms for pre-existing 
stores in some form.  One possibility which I am looking into is moving 
some of the hard work off onto the SQL server by making use of stored 
procedures instead of doing most things client side.  Another possible 
improvement is to virtualise the data returned to some degree so that 
actual values aren't retrieved from the database until explicitly needed 
which should give a boost to read speeds in some circumstances.

Despite this I would like to point out that I am introducing a couple of 
useful new features into the API that can benefit users of existing SQL 
Stores:
The ability to explicitly reference the default unnamed graph in SPARQL 
Query and Update using the URI <dotnetrdf:default-graph> (as requested by 
the iRingTools team) - this improvement applies to in-memory stores as 
wellAn SqlDataset - this is an implementation of a new abstraction layer 
which allows for querying out of memory data using the library's existing 
Leviathan SPARQL Engine.  This means that the contents of a SQL store need 
not be loaded into memory prior to querying them.  Query Performance is not 
as good as in-memory querying due to the overheads of going to and from the 
database but this is a trade off against not needing to use large amounts 
of RAM to realise the data in-memory prior to querying.Alongside the 
aforementioned I have been working on adding support for a number of new 
stores (both 3rd party and internally developed) which will provide a 
broader range of alternative stores to SQL stores should you wish to 
migrate from your existing SQL Stores.

If you have any questions/queries about this please let me know

Best Regards,

Rob Vesse
 

Re: [dotNetRDF-develop] patch to support WP7

[Rob V. <ra...@ec...>]

Thanks for those Peter

 

Have it building fine now - not done any testing myself yet as trying to get
new stuff and changes/fixes done for the 0.4.0 release (either late Jan/Feb)
first before I move into a testing phase closer to the release.

 

Thanks again

 

Rob

 

From: Peter Kahle [mailto:pk...@ka...] 
Sent: 05 January 2011 14:51
To: 'Rob Vesse'; 'dotNetRDF Developer Discussion and Feature Request'
Subject: Re: [dotNetRDF-develop] [dotNetRDF-bugs] patch to support WP7

 

Oops. Here's the two files I left out (Compatibility/HashSet.cs and
Properties/AssemblyInfo.cs).

 

The only tweak I made in the HAP project (which is called HAPPhone in the
source distro) was to change the AssemblyProduct to
HtmlAgilityPack.windowsphone, from the default of HtmlAgilityPack. I was
trying to mirror the Silverlight version, which is also simply
HtmlAgilityPack in the current release, but HtmlAgilityPack.silverlight in
the one included with dotNetRDF. I'm attaching the assembly as well, we'll
see if it's stripped by binary filters. If so, I'll resend with the
extension changed.

 

Thanks,

 

Peter

 

From: Rob Vesse [mailto:rv...@do...] 
Sent: Wednesday, January 05, 2011 07:31
To: 'dotNetRDF Developer Discussion and Feature Request'
Cc: pk...@ka...
Subject: RE: [dotNetRDF-bugs] patch to support WP7

 

Hi Peter

 

Thanks a lot for this J  I wasn't able to just apply the patch but was
simple enough just to copy and paste the data out of the patch file into the
appropriate places as was a small patch.

 

Did you actually tweak the WinPhone version of HtmlAgilityPack itself or did
you mean you tweaked the project file to use it instead of the Silverlight
one?  If you did change it yourself can you let me have the DLL you used

 

Also do you have the Compatability/HashSet.cs file you referenced in the
project file or is it the same as the unfinished one I created for the
aborted compact framework build?

 

Many Thanks,

 

Rob Vesse

 

From: Peter Kahle [mailto:pk...@ka...] 
Sent: 05 January 2011 02:49
To: dot...@li...
Subject: [dotNetRDF-bugs] patch to support WP7

 

Haven't had a chance to test this as much as I'd like, and I'm starting to
get swamped, so I thought I'd send it along so it doesn't rot. It works for
the simple stuff, loading, searching in-memory using simple selectors, etc.
I haven't had a chance to test SPARQL, and I'm almost certain using remote
endpoints will have issues.

 

I really didn't do anything but add a new project template for Windows Phone
that mimics the Silverlight one, and link it into the NAnt build. Oh, and I
grabbed a copy of the WinPhone version of the HtmlAgilityPack, tweaked it
slightly to mimic the way you have it set up for Silverlight, and included
that. I'm not certain that the Silverlight version wouldn't work as well.

 

I had to include a little kluge to support compiling in my environment
(64bit machines, 64bit build of NAnt), because Silverlight and WP7 require
use of the 32bit tools rather than the 64bit. I've left it in here, but feel
free to drop it if you think it's too specialized. (I actually had to use
the same code in the compile-silverlight target, but I decided not to send
that along. Let me know if you want it) Though it should work cleanly on
32bit machines as well. It's really something that should be fixed/added
into NAnt proper, but I'm not in a position to create a patch.

 

Also note that I'm using git to wrap SVN on my machine, so the patch may be
a little funky. Let me know and I'll see if I can generate something
cleaner.

 

Thanks,

 

Peter

 

 

Re: [dotNetRDF-develop] [dotNetRDF-bugs] patch to support WP7

[Peter K. <pk...@ka...>]

#if WINDOWS_PHONE 

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Collections;
using System.Collections.Generic;

namespace VDS.RDF
{
    /* Code stolen from http://social.msdn.microsoft.com/Forums/en-US/windowsphone7series/thread/e1dd3571-dfb8-4abe-b63a-62106d6a4965/ */
    public class HashSet<T> : ICollection<T>
    {
        private Dictionary<T, short> MyDict;

        public HashSet()
        {
            MyDict = new Dictionary<T, short>();
        }

        public HashSet(IEnumerable enumer)
        {
            MyDict = new Dictionary<T, short>();
            foreach (T item in enumer)
            {
                MyDict.Add(item,0);
            }
        }
        // Methods
        public void Add(T item)
        {
            // We don't care for the value in dictionary, Keys matter.
            MyDict.Add(item, 0);
        }

        public void Clear()
        {
            MyDict.Clear();
        }

        public bool Contains(T item)
        {
            return MyDict.ContainsKey(item);
        }

        public void CopyTo(T[] array, int arrayIndex)
        {
            throw new NotImplementedException();
        }

        public bool Remove(T item)
        {
            return MyDict.Remove(item);
        }

        public IEnumerator<T> GetEnumerator()
        {
            throw new NotImplementedException();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            throw new NotImplementedException();
        }

        public void UnionWith(IEnumerable<T> other)
        {
            foreach (T item in other)
            {
                try
                {
                    MyDict.Add(item, 0);
                }
                catch (ArgumentException) { }
            }
        }

        // Properties
        public int Count
        {
            get { return MyDict.Keys.Count; }
        }

        public bool IsReadOnly
        {
            get { return false; }
        }
    }

}

#endif

Re: [dotNetRDF-develop] [dotNetRDF-bugs] patch to support WP7

[Rob V. <rv...@do...>]

Hi Peter

 

Thanks a lot for this J  I wasn't able to just apply the patch but was
simple enough just to copy and paste the data out of the patch file into the
appropriate places as was a small patch.

 

Did you actually tweak the WinPhone version of HtmlAgilityPack itself or did
you mean you tweaked the project file to use it instead of the Silverlight
one?  If you did change it yourself can you let me have the DLL you used

 

Also do you have the Compatability/HashSet.cs file you referenced in the
project file or is it the same as the unfinished one I created for the
aborted compact framework build?

 

Many Thanks,

 

Rob Vesse

 

From: Peter Kahle [mailto:pk...@ka...] 
Sent: 05 January 2011 02:49
To: dot...@li...
Subject: [dotNetRDF-bugs] patch to support WP7

 

Haven't had a chance to test this as much as I'd like, and I'm starting to
get swamped, so I thought I'd send it along so it doesn't rot. It works for
the simple stuff, loading, searching in-memory using simple selectors, etc.
I haven't had a chance to test SPARQL, and I'm almost certain using remote
endpoints will have issues.

 

I really didn't do anything but add a new project template for Windows Phone
that mimics the Silverlight one, and link it into the NAnt build. Oh, and I
grabbed a copy of the WinPhone version of the HtmlAgilityPack, tweaked it
slightly to mimic the way you have it set up for Silverlight, and included
that. I'm not certain that the Silverlight version wouldn't work as well.

 

I had to include a little kluge to support compiling in my environment
(64bit machines, 64bit build of NAnt), because Silverlight and WP7 require
use of the 32bit tools rather than the 64bit. I've left it in here, but feel
free to drop it if you think it's too specialized. (I actually had to use
the same code in the compile-silverlight target, but I decided not to send
that along. Let me know if you want it) Though it should work cleanly on
32bit machines as well. It's really something that should be fixed/added
into NAnt proper, but I'm not in a position to create a patch.

 

Also note that I'm using git to wrap SVN on my machine, so the patch may be
a little funky. Let me know and I'll see if I can generate something
cleaner.

 

Thanks,

 

Peter

 

 

[dotNetRDF-develop] Support over the Holiday Period

[Rob V. <rv...@do...>]

Hello All

Happy Holidays to you all!

This is just an informative message to say that from today until the New 
Year I will be travelling visiting family for the holidays and so support 
requests may take longer than usual to resolve.  Also there may be some 
issues that I am unable to resolve as I will only have my laptop and won't 
have access to certain software for testing and debugging - namely most of 
the 3rd party Triple Stores which dotNetRDF supports.

I will try and respond to any support requests but can't guarantee as fast 
a response as I usually try to give

Thanks for your understanding

Rob Vesse

 

Re: [dotNetRDF-develop] Suggestions for where to start for porting to Windows Phone 7?

[Rob V. <rv...@do...>]

I'm using NAnt 0.91 (Build 0.91.3881.0; alpha2; 17/08/2010) and that works 
fine for me - appears to be latest release

You probably need to have the .Net 4.0 SDK installed for it to run properly 
which you can either download from Microsoft or if you have VS2010 you 
should already have installed.

Regards,

Rob

----------------------------------------
From: "Peter Kahle" <pk...@ka...>
Sent: 20 December 2010 12:33
To: rv...@do..., "dotNetRDF Developer Discussion and Feature 
Request" <dot...@li...>
Subject: RE: [dotNetRDF-develop] Suggestions for where to start for porting 
to Windows Phone 7? 

Thanks Rob, that should be enough to get me started. One question, though. 
What version of nant are you using? 0.90 doesn't seem to support .Net 4.0, 
and the latest alpha of 0.91 just crashes.

Thanks,
Peter

Sent from my Windows Phone

----------------------------------------

From: Rob Vesse
Sent: Saturday, December 18, 2010 8:38
To: dotNetRDF Developer Discussion and Feature Request
Cc: pk...@ka...
Subject: re: [dotNetRDF-develop] Suggestions for where to start for porting 
to Windows Phone 7?


> Hi Peter

> 

> That's great that you want to contribute a Windows Phone 7 port.

> 

> My instinct would be to start with the Silverlight library as a basis and 
use an additional compiler symbol (e.g. WIN_PHONE_7) alongside #if 
WIN_PHONE_7 to add in appropriate compatability fixes and work arounds into 
the core library codebase.  I've had a quick browse through the Silverlight 
vs Windows Phone documentation on MSDN and can't see anything obvious that 
is missing that would need to be worked around but until you create a build 
and start testing you won't know for sure.

> 

> I wouldn't use the Lite library as that is a cut down build for full .Net 
for people who want less dependencies and a smaller memory footprint i.e. 
it isn't set up to run under Silverlight.

> 

> With regards to build process the Silverlight build is currently built 
against Silverlight 4 so would need to be downgraded to using Silverlight 3 
to work on Windows Phone 7 as I understand it.  Essentially the Silverlight 
project file is a template that only references a few additional code files 
that provides compatability classes and extension methods to get the core 
library to build under Silverlight.  The project file defines a load of 
compiler symbols to use which basically disable a variety of features that 
can't be supported under Silverlight.  Most of these symbols will probably 
be needed for Windows Phone 7 though there is one/two you might be able to 
remove (possibly NO_URICACHE)

> 

> The actual project file is then generated using a tool found in 
Trunk/Build/ExportCoreContentsToTemplate in the SVN repository.  I tend to 
build these actual builds using the nant and the build file found in 
Trunk/Build/nant - take a look at the projectgen-silverlight and the 
compile-silverlight targets to see how this works.  Basically the tool is 
run to generate the actual project file from the template file and then 
MSBuild is invoked to actually compile the project file.

> 

> So what I would recommend you do is use your preferred IDE to create an 
empty Windows Phone 7 project and set all the required compiler symbols 
plus add the Silverlight compatability classes as linked files in the 
project (ensure you select Add as Link when adding them to the project).  
Then create your own nant targets which generate the project file and try 
to compile it.  If it doesn't compile look into the various errors and make 
whatever workarounds are needed.  Once its compiled then you can start 
testing it and seeing how and whether it works and feed back any bugs that 
need fixing to this list or the bugs list 
(dot...@li...)

> 

> If you need more help/guidance please let me know

> 

> Regards,

> 

> Rob Vesse

> 

> ----------------------------------------

> From: "Peter Kahle" <pk...@ka...>

> Sent: 17 December 2010 22:55

> To: dot...@li...

> Subject: [dotNetRDF-develop] Suggestions for where to start for porting 
to Windows Phone 7? 

> 

> I'd like to start trying to work with dotnetrdf to get it compilable on 
WP7, but since I'm not really up on the code, I don't know where I should 
think about starting. Right now, I'm leaning towards starting with the 
Silverlight library, or the lite library. Anyone have any suggestions or 
pointers they could offer? Thanks, Peter  

> 

Re: [dotNetRDF-develop] Suggestions for where to start for porting to Windows Phone 7?

[Peter K. <pk...@ka...>]

<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=utf-8"></HEAD>
<BODY>
<DIV style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri,sans-serif">Thanks Rob, that should be enough to get me started. One question, though. What version of nant are you using? 0.90 doesn't seem to support .Net 4.0, and the latest alpha of 0.91 just crashes.<BR><BR>Thanks,<BR>Peter<BR><BR>Sent from my Windows Phone</DIV>
<HR>
<SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">From: </SPAN><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">Rob Vesse</SPAN><BR><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">Sent: </SPAN><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">Saturday, December 18, 2010 8:38</SPAN><BR><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">To: </SPAN><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">dotNetRDF Developer Discussion and Feature Request</SPAN><BR><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">Cc: </SPAN><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">pk...@ka...</SPAN><BR><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">Subject: </SPAN><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma,sans-serif">re: [dotNetRDF-develop] Suggestions for where to start for porting to Windows Phone 7?</SPAN><BR><BR></BODY></HTML><br />
<br />
&gt; Hi Peter<br />
&gt; <br />
&gt; That's great that you want to contribute a Windows Phone 7 port.<br />
&gt; <br />
&gt; My instinct would be to start with the Silverlight library as a basis and use an additional compiler symbol (e.g. WIN_PHONE_7) alongside #if WIN_PHONE_7 to add in appropriate compatability fixes and work arounds into the core library codebase.  I've had a quick browse through the Silverlight vs Windows Phone documentation on MSDN and can't see anything obvious that is missing that would need to be worked around but until you create a build and start testing you won't know for sure.<br />
&gt; <br />
&gt; I wouldn't use the Lite library as that is a cut down build for full .Net for people who want less dependencies and a smaller memory footprint i.e. it isn't set up to run under Silverlight.<br />
&gt; <br />
&gt; With regards to build process the Silverlight build is currently built against Silverlight 4 so would need to be downgraded to using Silverlight 3 to work on Windows Phone 7 as I understand it.  Essentially the Silverlight project file is a template that only references a few additional code files that provides compatability classes and extension methods to get the core library to build under Silverlight.  The project file defines a load of compiler symbols to use which basically disable a variety of features that can't be supported under Silverlight.  Most of these symbols will probably be needed for Windows Phone 7 though there is one/two you might be able to remove (possibly NO_URICACHE)<br />
&gt; <br />
&gt; The actual project file is then generated using a tool found in Trunk/Build/ExportCoreContentsToTemplate in the SVN repository.  I tend to build these actual builds using the nant and the build file found in Trunk/Build/nant - take a look at the projectgen-silverlight and the compile-silverlight targets to see how this works.  Basically the tool is run to generate the actual project file from the template file and then MSBuild is invoked to actually compile the project file.<br />
&gt; <br />
&gt; So what I would recommend you do is use your preferred IDE to create an empty Windows Phone 7 project and set all the required compiler symbols plus add the Silverlight compatability classes as linked files in the project (ensure you select Add as Link when adding them to the project).  Then create your own nant targets which generate the project file and try to compile it.  If it doesn't compile look into the various errors and make whatever workarounds are needed.  Once its compiled then you can start testing it and seeing how and whether it works and feed back any bugs that need fixing to this list or the bugs list (dot...@li...)<br />
&gt; <br />
&gt; If you need more help/guidance please let me know<br />
&gt; <br />
&gt; Regards,<br />
&gt; <br />
&gt; Rob Vesse<br />
&gt; <br />
&gt; ----------------------------------------<br />
&gt; From: &quot;Peter Kahle&quot; &lt;pk...@ka...&gt;<br />
&gt; Sent: 17 December 2010 22:55<br />
&gt; To: dot...@li...<br />
&gt; Subject: [dotNetRDF-develop] Suggestions for where to start for porting to Windows Phone 7? <br />
&gt; <br />
&gt; I'd like to start trying to work with dotnetrdf to get it compilable on WP7, but since I'm not really up on the code, I don't know where I should think about starting. Right now, I'm leaning towards starting with the Silverlight library, or the lite library. Anyone have any suggestions or pointers they could offer? Thanks, Peter  <br />
&gt; <br />

Re: [dotNetRDF-develop] Suggestions for where to start for porting to Windows Phone 7?

[Rob V. <rv...@do...>]

Hi Peter

That's great that you want to contribute a Windows Phone 7 port.

My instinct would be to start with the Silverlight library as a basis and use an additional compiler symbol (e.g. WIN_PHONE_7) alongside #if WIN_PHONE_7 to add in appropriate compatability fixes and work arounds into the core library codebase.  I've had a quick browse through the Silverlight vs Windows Phone documentation on MSDN and can't see anything obvious that is missing that would need to be worked around but until you create a build and start testing you won't know for sure.

I wouldn't use the Lite library as that is a cut down build for full .Net for people who want less dependencies and a smaller memory footprint i.e. it isn't set up to run under Silverlight.

With regards to build process the Silverlight build is currently built against Silverlight 4 so would need to be downgraded to using Silverlight 3 to work on Windows Phone 7 as I understand it.  Essentially the Silverlight project file is a template that only references a few additional code files that provides compatability classes and extension methods to get the core library to build under Silverlight.  The project file defines a load of compiler symbols to use which basically disable a variety of features that can't be supported under Silverlight.  Most of these symbols will probably be needed for Windows Phone 7 though there is one/two you might be able to remove (possibly NO_URICACHE)

The actual project file is then generated using a tool found in Trunk/Build/ExportCoreContentsToTemplate in the SVN repository.  I tend to build these actual builds using the nant and the build file found in Trunk/Build/nant - take a look at the projectgen-silverlight and the compile-silverlight targets to see how this works.  Basically the tool is run to generate the actual project file from the template file and then MSBuild is invoked to actually compile the project file.

So what I would recommend you do is use your preferred IDE to create an empty Windows Phone 7 project and set all the required compiler symbols plus add the Silverlight compatability classes as linked files in the project (ensure you select Add as Link when adding them to the project).  Then create your own nant targets which generate the project file and try to compile it.  If it doesn't compile look into the various errors and make whatever workarounds are needed.  Once its compiled then you can start testing it and seeing how and whether it works and feed back any bugs that need fixing to this list or the bugs list (dot...@li...)

If you need more help/guidance please let me know

Regards,

Rob Vesse

----------------------------------------
From: "Peter Kahle" <pk...@ka...>
Sent: 17 December 2010 22:55
To: dot...@li...
Subject: [dotNetRDF-develop] Suggestions for where to start for porting to Windows Phone 7? 

I'd like to start trying to work with dotnetrdf to get it compilable on WP7, but since I'm not really up on the code, I don't know where I should think about starting. Right now, I'm leaning towards starting with the Silverlight library, or the lite library. Anyone have any suggestions or pointers they could offer? Thanks, Peter  

[dotNetRDF-develop] Suggestions for where to start for porting to Windows Phone 7?

[Peter K. <pk...@ka...>]

I'd like to start trying to work with dotnetrdf to get it compilable on WP7,
but since I'm not really up on the code, I don't know where I should think
about starting. Right now, I'm leaning towards starting with the Silverlight
library, or the lite library. Anyone have any suggestions or pointers they
could offer?

 

Thanks,

 

Peter

 

 

Re: [dotNetRDF-develop] Planned Merge of 0.4.0 Branch into Trunk

[Rob V. <rv...@do...>]

We're pushing this back a few days as we've had a request to release some 
interop code which is reliant on the 0.3.1 branch so the merge will be 
delayed until that is sorted

Rob

----------------------------------------
From: "Rob Vesse" <rv...@do...>
Sent: 29 October 2010 09:35
To: dot...@li...
Subject: [dotNetRDF-develop] Planned Merge of 0.4.0 Branch into Trunk 

Hi All

Please be aware that I am planning on merging some of the 0.4.0 Branch 
(specifically the core library) back into Trunk on Monday.  If people have 
applications that are reliant on the 0.3.1 version/Trunk of dotNetRDF and 
don't yet want to move to the incomplete and potentially unstable 0.4.0 
version they should download the latest nightly's from SVN which can be 
found in Trunk\bin

These nightly's are essentially the 0..3.1 version as released with a 
couple of bug fixes from the 0.4.0 branch backported to it.

If you have any questions/objections please let me know before Monday 
morning

Thanks,

Rob Vesse

[dotNetRDF-develop] Planned Merge of 0.4.0 Branch into Trunk

[Rob V. <rv...@do...>]

Hi All

Please be aware that I am planning on merging some of the 0.4.0 Branch 
(specifically the core library) back into Trunk on Monday.  If people have 
applications that are reliant on the 0.3.1 version/Trunk of dotNetRDF and 
don't yet want to move to the incomplete and potentially unstable 0.4.0 
version they should download the latest nightly's from SVN which can be 
found in Trunk\bin

These nightly's are essentially the 0.3.1 version as released with a couple 
of bug fixes from the 0.4.0 branch backported to it.

If you have any questions/objections please let me know before Monday 
morning

Thanks,

Rob Vesse
 

[dotNetRDF-develop] RFC - Feature Requests/Bug Reports for upcoming 0.3.1 release

[Rob V. <rv...@do...>]

Hi All

I'm hoping to get the next release (0.3.1) made in the next couple of weeks 
so I'm solicitating any final feature requests/bug reports prior to this 
release.

Fixes and Changes for this release so far are as follows:

Added
- New RdfXmlWriter which is a streaming writer based on FastRdfXmlWriter
- New Writing.Formatting namespaces
 - Introduces ITripleFormatter, INodeFormatter, IUriFormatter and 
ICharFormatter interfaces
 - Provides an easy to use and reusable means of formatting nodes and 
triples
 - Refactored existing code to use formatters for writing
- New Parsing.Validation namespace
 - Provides simple classes for validating syntax
- SPARQL Views
 - Create Graphs which are dynamically generated from a SPARQL Query and 
updated when the underlying data changes/on demand
- Silverlight Compatability
 - Emulated HtmlTextWriter and HttpUtility for Silverlight compatability
 - Variety of compiler symbols defined to allow various library features to 
be disabled
 - SparqlXmlParser and SparqlXmlWriter use XmlReader and XmlWriter 
respectively when no XML DOM API available
 - TriXParser and TriXWriter use XmlReader and XmlWriter respectively when 
no XML DOM API available

Changed
- Bug Fixes
 - SqlTripleStore initialises correctly and persists updates correctly when 
used with an ISparqlUpdateProcessor
 - More intelligent parsing of Blank Node IDs from SPARQL Results
 - TriG Writer outputs all required @prefix definitions and generates 
consistent QNames
 - URI Loader Cache handles File IO errors gracefully
 - Rare forms of Numeric Literals now supported by Turtle, N3, TriG and 
SPARQL Parsers
 - Potentially ambigious QNames and Plain Literals now no longer cause 
parsing errors in Turtle, N3, TriG and SPARQL Parsers
- General Improvements
 - INamespaceMapper interface extracted and some visibility changes to 
NamespaceMapper methods
- SPARQL Improvements
 - Optimisations for ASK queries
 - Optimisations for CONSTRUCT/DESCRIBE/SELECT where LIMIT/OFFSET is used
- ASP.Net Improvements
 - Better caching support for BaseGraphHandler - now sends ETag in 
responses and may response with 304 Not Modified as appropriate

Removed
- Obsolete RdfXmlWriter removed

Please note that I am primarily only looking for issues that should be 
addressed for this next release.  These may be minor feature requests e.g. 
additional overloads of methods, error message improvements or bug reports 
for bugs that are not already covered in the above list.

Major feature requests are always welcome but obviously these will not be 
considered for the immediate next release, if you would like to make such a 
request please let us know and we'll reply as to whether such a feature 
can/will be included and a tentative timeline for such a feature.

Best Regards,
Rob Vesse
 

Re: [dotNetRDF-develop] DESCRIBE query and Sesame

[Rob V. <ra...@ec...>]

Ok I will try and get a Sesame instance up and running so I can debug the problem properly.

 

Which error messages in particular are unhelpful, improving error messages is one of the things I have been working on currently so if you could tell me which messages are problematic I’ll aim to improve them.  I guess that you probably mean the generic  "A HTTP error occurred while querying the Store" error that you get from the Sesame connector?  The problem here is that when making the query over HTTP I don’t necessarily get a coherent response back from the server, I could potentially extract the returned response text (if any) from the response and append that to the exception message if that would help?  Though I notice that the server doesn’t necessarily return any error messages in the response depending on where the error is in the query.

 

Rob

 

From: Sergey Novikov [mailto:ser...@gm...] 
Sent: 08 September 2010 10:59
To: Rob Vesse
Subject: Re: DESCRIBE query and Sesame

 

Hi, Rob.

 

Exported from SVN latest version today. Exception exist and message the same.

 

By the way. When I execute sparql queries that contains errors - messages from exceptions is not helpfull at all. Don't know if it possible to do something, but any improvements would be great.


Best regards,

Sergey Novikov



On Tue, Sep 7, 2010 at 12:45 PM, Rob Vesse <ra...@ec...> wrote:

Hi Sergey

 

Think I have fixed this bug in SVN as of revision 970.  Can you confirm for me whether this is now fixed as I don’t have an instance of plain Sesame itself to test against (I test against AllegroGraph which implements the Sesame HTTP protocol).

 

By the way I see from your stack trace you may still be using dotNetRDF 0.2.2?  If you are you should consider upgrading to the 0.3.0 release or the latest SVN builds asap as they contain many bug fixes and improvements particularly with regards to adding many more SPARQL 1.1 Query and Update features.

 

Best Regards,

 

Rob Vesse

 

From: Sergey Novikov [mailto:ser...@gm...] 
Sent: 03 September 2010 16:11
To: ra...@ec...
Subject: DESCRIBE query and Sesame

 

Hi, Rob

 

I'm having some difficulties with DESCRIBE construction in DotNetRDF.

 

For instance, this simple query:

 

return store.ExecuteQuery(@"DESCRIBE <http://test.com/TestPerson1>");

 

cause exception:

 

[VDS.RDF.Parsing.RdfParseException] = {"The input was not a single boolean value as a String"}

 

with stack trace:

 

   at VDS.RDF.Parsing.SparqlBooleanParser.Load(SparqlResultSet results, StreamReader input) in D:\Upload\!DevelopSemantic\RipicsSemantic\Semantic\dotNetRDF022Alpha2010-08-18\Trunk\Libraries\core\Parsing\SparqlBooleanParser.cs:line 87

   at VDS.RDF.Storage.SesameHttpProtocolConnector.Query(String sparqlQuery) in D:\Upload\!DevelopSemantic\RipicsSemantic\Semantic\dotNetRDF022Alpha2010-08-18\Trunk\Libraries\core\Storage\SesameHttpProtocolConnector.cs:line 169

   at VDS.RDF.NativeTripleStore.ExecuteQuery(String query) in D:\Upload\!DevelopSemantic\RipicsSemantic\Semantic\dotNetRDF022Alpha2010-08-18\Trunk\Libraries\core\Core\NativeTripleStore.cs:line 78

   at CommonMethods.RDFBasicIO.SPARQLRequest(String query) in D:\Upload\!DevelopSemantic\RipicsSemantic\AssetManagement\Common\RDFBasicIO.cs:line 105

 

I've tested this query through sesame web interface and it work fine returning me couple relevant results. 

 

Can you find what is wrong?

 

Thank you.


Best regards,

Sergey Novikov

 

[dotNetRDF-develop] [ANN] dotNetRDF 0.3.0 Released

[Rob V. <ra...@ec...>]

Hi all

I have just released version 0.3.0 of dotNetRDF - a free and open source
.Net library for working with RDF.

Homepage:
http://www.dotnetrdf.org

API Documentation:
Informal - http://www.dotnetrdf.org/content.asp?pageID=dotNetRDF%20API
Formal MSDN style - http://www.dotnetrdf.org/api/

An example SPARQL Query endpoint can be found at
http://www.dotnetrdf.org/demos/leviathan/

New in this release:
- Improved SPARQL 1.1 Support
 - SPARQL 1.1 Federated Query
 - SPARQL 1.1 Update
 - SPARQL 1.1 Uniform HTTP Protocol for RDF Graph Management
- RDFa 1.1 parsing
- New configuration API
- Rewritten ASP.Net integration for easier and more flexible configuration
- Client for Pellet Server
- Various bug fixes and improvements

Any comments and feedback would be appreciated.  Please be aware that this
is still considered an Alpha release and there are undoubtedly some
undiscovered bugs in the library - reports and patches are welcome.

Rob Vesse

dotNetRDF Lead Developer
================================================================
Developer Discussion & Feature Request -
dot...@li...
Bug Reports - dot...@li...
User Help & Support - dot...@li...

Website: http://www.dotnetrdf.org
User Guide: http://www.dotnetrdf.org/content.asp?pageID=User%20Guide
API: http://www.dotnetrdf.org/api/
================================================================

Re: [dotNetRDF-develop] NullReferenceException in RdfaParser

[Broekstra, J. <jee...@wu...>]

Rob Vesse wrote:

> Yes there was a bug in the parser which is now fixed in SVN
> as of revision 857 and will be in the next release but the
> main problem is that much of your syntax is invalid and so
> actually gets ignored.

I know, in fact my main reason for trying out your RDFa parser was to try and use it to figure out what I was doing wrong. I've read my share of cryptic W3C specs but the RDFa one is in a league of its own to be honest... Good to know the bug is known and fixed!

[snip various very useful tips]

Thanks for your help Rob, I'll putter on and try and get it right :)

Cheers,

Jeen

Re: [dotNetRDF-develop] NullReferenceException in RdfaParser

[Rob V. <rv...@vd...>]

Hi Jeen

Yes there was a bug in the parser which is now fixed in SVN as of revision 857 and will be in the next release but the main problem is that much of your syntax is invalid and so actually gets ignored.

For example if I run your webpage through the W3C validator I only get the following triples:

<http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.wurvoc.org/vocabularies/om-1.6/Ratio_scale>.
<http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale> <http://www.w3.org/1999/xhtml/vocab#stylesheet> <http://www.wurvoc.org/css/wurvoc-vocabularies.css>.
<http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale> <http://creativecommons.org/ns#attributionURL> <http://www.wurvoc.org/>.
<http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale> <http://www.w3.org/2000/01/rdf-schema#isDefinedBy> <http://www.wurvoc.org/vocabularies/om-1.6/>.
<http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale> <http://www.w3.org/1999/xhtml/vocab#license> <http://creativecommons.org/licenses/by/3.0/nl/>.
<http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale> <http://www.w3.org/2000/01/rdf-schema#label> "Kelvin scale"@en. 

Also when you invoke it with the code you sent me you are feeding in a raw HTTP response 
stream so the Graph is not aware of it's Base URI so even the few legal 
triples in your syntax cannot be generated, you need to explicitly specify the Base Uri of the Graph like so before loading into it:

g.BaseUri = new Uri("http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale"); 

Alternatively you can add a <base href="http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale" /> elememt to the <head> of your XHTML document.

I found that other RDFa validators will only produce output similar to the above, my RDFa parser with the fix applied will produce a couple more of triples than that but they don't appear to be the URIs you are intending (comparing with the RDF/XML version) and are only generated as my parser in the latest SVN builds of dotNetRDF has RDFa 1.1 support so interprets some invalid RDFa 1.0 as valid RDFa 1.1 syntax

In several places you have either used prefixes you haven't defined or you are using CURIEs without any prefix which appears to be the main issue with your RDFa.  I'm not an expert in RDFa so I'd ask on the pub...@w3... mailing list for help with getting your syntax correct

The alternative way to load RDF from the web is to use the UriLoader class so you don't have to explicitly state the parser to be used, only problem I noticed when trying this with your URL is that it gives back the RDF/XML instead because of the Accept header which the UriLoader will send.

One final thing that might be of use to you is that you can attach an event handler to the Warning event of the parser so that you get warning messages about invalid CURIEs and URIs e.g.

parser.Warning += new RdfReaderWarning(this.HandleError); 

Hope this helps

Best Regards,

Rob Vesse

----------------------------------------
From: "Broekstra, Jeen" <jee...@wu...>
Sent: 30 July 2010 14:20
To: "dot...@li..." <dot...@li...>
Subject: [dotNetRDF-develop] NullReferenceException in RdfaParser 

Hi there,

I have just started trying out DotNetRDF, and sofar am very impressed. Great work!

However, I have ran into a problem. I am trying to use the RdfaParser in a simple test project, but get a NullReferenceException:

System.NullReferenceException was unhandled
  Message="Object reference not set to an instance of an object."
  Source="dotNetRDF"
  StackTrace:
       at VDS.RDF.Triple..ctor(INode subj, INode pred, INode obj)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.Parse(RdfAParserContext context)
       at VDS.RDF.Parsing.RdfAParser.Load(IGraph g, StreamReader input)
       at DotNetRDFTest.Program.Main(String[] args) in D:\Documents\Visual Studio 2008\Projects\DotNetRDFTest\Program.cs:line 24

The code I am executing is quite simple:

	Graph g = new Graph();
	RdfAParser parser = new RdfAParser();

	StreamReader reader = new StreamReader(WebRequest.Create("http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale").GetResponse().GetResponseStream());

	parser.Load(g, reader);

The exception occurs on the parser.Load. 

It may be that the RDFa document I am parsing contains syntax errors (I've generated it myself, but I'm still struggling a bit with the exact RDFa syntax). Regardless, it seems to me that the parser should handle unexpected content more gracefully than with a NRE :)

Is this a bug in the parser, or am I doing something wrong in invoking it?

Cheers,

Jeen

PS using DotNetRDF 0.2.2 alpha and .Net 3.5. Also included a ref to the HtmlAgilityPack.
-- 
dr. J. Broekstra
Wageningen UR, Food & Biobased Research
Intelligent Systems group
P.O. Box 17, 6700 AA Wageningen
Wageningen Campus, Building 118, Bornse Weilanden 9, 6708 WG Wageningen
Tel. +31 (0)317 480145
http://www.fbresearch.nl/InformationManagement

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[dotNetRDF-develop] NullReferenceException in RdfaParser

[Broekstra, J. <jee...@wu...>]

Hi there,

I have just started trying out DotNetRDF, and sofar am very impressed. Great work!

However, I have ran into a problem. I am trying to use the RdfaParser in a simple test project, but get a NullReferenceException:

System.NullReferenceException was unhandled
  Message="Object reference not set to an instance of an object."
  Source="dotNetRDF"
  StackTrace:
       at VDS.RDF.Triple..ctor(INode subj, INode pred, INode obj)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.ProcessElement(RdfAParserContext context, RdfAEvaluationContext evalContext, HtmlNode currElement)
       at VDS.RDF.Parsing.RdfAParser.Parse(RdfAParserContext context)
       at VDS.RDF.Parsing.RdfAParser.Load(IGraph g, StreamReader input)
       at DotNetRDFTest.Program.Main(String[] args) in D:\Documents\Visual Studio 2008\Projects\DotNetRDFTest\Program.cs:line 24

The code I am executing is quite simple:

	Graph g = new Graph();
	RdfAParser parser = new RdfAParser();

	StreamReader reader = new StreamReader(WebRequest.Create("http://www.wurvoc.org/vocabularies/om-1.6/Kelvin_scale").GetResponse().GetResponseStream());

			
	parser.Load(g, reader);

The exception occurs on the parser.Load. 

It may be that the RDFa document I am parsing contains syntax errors (I've generated it myself, but I'm still struggling a bit with the exact RDFa syntax). Regardless, it seems to me that the parser should handle unexpected content more gracefully than with a NRE :)

Is this a bug in the parser, or am I doing something wrong in invoking it?

Cheers,

Jeen

PS using DotNetRDF 0.2.2 alpha and .Net 3.5. Also included a ref to the HtmlAgilityPack.
-- 
dr. J. Broekstra
Wageningen UR, Food & Biobased Research
Intelligent Systems group
P.O. Box 17, 6700 AA Wageningen
Wageningen Campus, Building 118, Bornse Weilanden 9, 6708 WG Wageningen
Tel. +31 (0)317 480145
http://www.fbresearch.nl/InformationManagement

[dotNetRDF-develop] "Updating" triple

[Michael F. <fr...@gm...>]

Hello

Question: I have an entity that has a property (a count of some sort)
that I need to change. I do this by querying for all triples with the
entity as object and the "count" as predicate, and then loop over
them, retracting each. I then assert a triple with the new value. This
doesn't seem to work: The property dissapears from subsequent queires
(so the remove presumably works), even though I assert a new one. If I
look in the database, it looks as thought there are multiple triples,
including the onew with old values, but none of them show up.

What am I doing wrong?
Michael

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(+45) 27122799
Sapere aude

Re: [dotNetRDF-develop] Updating/inserting-into DB-backed graph without doing LoadGraph

[Michael F. <fr...@gm...>]

On Mon, Jun 21, 2010 at 4:57 PM, Michael Friis <fr...@gm...> wrote:
>> Note that this persistence is done batched in the background so changes
>> aren't persisted instantaneously and it's worth explicitly calling the
>> Dispose() method on the Graph when you're done with it and this forces any
>> remaining unpersisted changes to be persisted to the Store.
> I'm using 780 right now. When doing:
>            graph.Flush();
>            graph.Dispose();
> ... my (console) app sometimes hangs...
It's as though, if I create and dispose more than one
WriteOnlyStoreGraph, the app hangs.

Michael

-- 
http://friism.com
(+45) 27122799
Sapere aude

Re: [dotNetRDF-develop] Updating/inserting-into DB-backed graph without doing LoadGraph

[Michael F. <fr...@gm...>]

> Note that this persistence is done batched in the background so changes
> aren't persisted instantaneously and it's worth explicitly calling the
> Dispose() method on the Graph when you're done with it and this forces any
> remaining unpersisted changes to be persisted to the Store.
I'm using 780 right now. When doing:
            graph.Flush();
            graph.Dispose();
... my (console) app sometimes hangs...

Michael

-- 
http://friism.com
(+45) 27122799
Sapere aude