magento-openerp-synchro module: we moved to Launchpad!

Sure Google Code Hosting is great,

But we are now seeing too much interest in that connector poping all over the world to continue the development in a centralized way. Also, we have been contacted by Jordi Esteve, the primary extern OpenERP contributor (after Launchpad stats) who wanted to jump in and join efforts, so he also asked us to move the contribution process forward.

That's why we have the pleasure to announce you that we migrated our development trunk from Google Code SVN to Bazaar on Launchpad, meaning we just use the advised OpenERP community advised distributed development platform. Also notice that we took care of migrating the previous SVN commits.

That was also the occasion to split the development in two branches:

• a 4.2 compatible maintenance Branch. That one is for the conservative folks who can't afford migrating to OpenERP v5 https://code.launchpad.net/~openerp-commiter/openobject-addons/4.2-extra-addons
  
• a 5.x branch where all the new interesting stuff is expected to happen: https://code.launchpad.net/~openerp-commiter/openobject-addons/trunk-extra-addons

In both cases, the OpenERP addon module name is now called magento_openerp_synchro.
The last SVN version (revision #27) has been ported as bzr revision #3581.1.9 on v5 branch and rev #148 in 4.2 branch. Later on both branches got a fix for issue http://code.google.com/p/magento-openerp-smile-synchro/issues/detail?id=31
v5 branch got even more attention and code clean up.

So you are very much welcome to jump in and contribute to whatever branch you need. Still, before adding any serious extra feature, we would like to insist that some refactoring should be undertaken BEFORE bloating the code.

Especially:

1. Too much code is lying inside the OpenERP wizard layers. That was a bad design choice making it hard for additionnal third party modules to extend the connector behavior and add custom features that way OpenERP allows it (thanks to its extensive OOP design). Instead, that code should be moved INSIDE THE OBJECT LAYER. That shouldn't be to hard, it's only about extracting methods, putting them in the appropriated objects (sale order, product...) and calling those methods from the wizards instead. For instance we deployed a derived version of that connector for a customer along with the sale_supplier_direct_delivery module and we had to hardcode the connector to make it account for the direct delivery eventuallity. With the new design things should work more seamlessly. See the following tracker: http://code.google.com/p/magento-openerp-smile-synchro/issues/detail?id=32
2. The sale order push feature (from Magento) has not beeing integrated properly yet and is still polluting the code. It has been a wonderfull contribution by Charles Galpin, but we had not time to integrate it the way we wanted to and it has not been tested extensively. Instead, we would like to remove the push code from Magento and instead makes Magento call OpenERP and tell him to pull the given sale order reusing it's standar sale order import code. Finally that design should be able to deal with possible network or OpenERP failure and flag failing push inside Magento for later processing. Not at top priority, but something you should be aware of. See following tracker: http://code.google.com/p/magento-openerp-smile-synchro/issues/detail?id=33
   
3. Finally, we insist that we din't take care yet of exposing ALL OpenERP XML/RPC server webservice the standard Magento way. One of the consequences is that currently importing sale orders is not secure unless you block external connections by IP at say an Apache level. A much better way would be to properly expose our custom extra webservice the Magento way, see the following tracker: http://code.google.com/p/magento-openerp-smile-synchro/issues/detail?id=6
   

Meanwhile we welcome Jordi Esteve as a core contributor + project member. We know that things have been a bit slow with Smile and the connector recently (we are flooded by OpenERP non Magento demand), but we really hope to help moving foward as much as we can. We really hope all those inputs will streamline the installation process + natively supported features while minimizing the required development skills. Enjoy!

New planet for Magento - OpenERP synchro module

Hi, I'm Raphaël Valyi, one of the main author of the synchro module between OpenERP and Magento. Some 10 months ago, after completing an extensive study about open source ERP's, I convinced Smile, my employer, to support that synchro module allowing Magento and OpenERP to work together. Some two months later, thanks to Smile and the tireless work of Sylvain Pamart, we got that connector in pretty good shape already.

Over the time, we improved it and tried to integrate community contributions as much as possible.

Since then, our OpenERP schedule at Smile got totally loaded with customer contracts letting us little time for the community even if Smile is still commited to support the effort in theory (my boss agrees on a 2 man days per month effort so far, as long as we have no higher priority, and that's the catch) . So unfortunately, it means that the connector is always lagging behind direct commercial activities.

Anyway, as I do personally see interest in pushing that connector forward, I'm taking on my spare time to give you updates about the connector in this blog, under the magento-openerp-synchro tag, so it get exported to our brand new Connector Yahoo Pipes powered planet mashup: http://pipes.yahoo.com/pipes/pipe.info?_id=7mpa3ckG3hGCuJSWPxJ3AQ

Ideally, I'll let any contributor (including Smile.fr) post in that planet when they contribute in the future. So the corporate work supported by Smile.fr will hence probably be published both here and on the corporate blog, that is http://blog.smile.fr/le-blog-des-consultants.

So I hope this planet will be a fair place to give updates about the connector while accommodating corporate, personal and community contributions. Feel also free to comment in the respective planet blogs.

Finally note that this planet is managed as a Yahoo Pipes aggregator wrapped inside a Google Gadget eventually. You can contact me to have your blog (+specific tag) included in that planet if you wish.

Raphaël Valyi

OpenERP running on Java (Jython) - ROUND 1

Hi folks,

Looking for an open source ERP that doesn't suck? Well there is at least one: OpenERP. Like it or not it's Python based. For most of the things this is a perfect fit, but let's face it, Python has less enterprise acceptance and the lower layers of that ERP could also have been powered by a powerfull virtual machine. And since building a new ERP can't really take less than 3 years, the situation will hardly evolve any time soon, so we better deal with it: I bet my money OpenERP will now take the market by storm, I don't see anything stopping it to take the lead, at least for the next 5 years.

So I wanted to show the world that it was possible to back OpenERP by the Java platform, much like it's now being admitted that Java is the best bed for Ruby on Rails applications thanks to JRuby. I built a proof of concept. Now I hope some get the message and join efforts to make it happen. I'll hardly finish that journey in my spare time, but hopefully, some people start to release how important this is and how close we are and help covering the extra miles to get it in production running on Java. Of course, OpenERP doesn't need to run Java to be the best ERP already, it is just that it could be even better. And if you want to help out, I'll be there too.

what about the claimed Java based ERP's?

I've been myself a Java programmer since around 2003, even created my first open source project on Sourceforge back in 2004 (EmSim http://sourceforge.net/projects/emsim/), later on I used those skills in a variety of advanced projects when working at Amadeus and Smile.fr. But, like it or not, after deep investigation, my conclusion is that the best open source ERP was coded in Python. I've looked deep inside Java based or claimed ERP's such as Ofbiz, Neogia, JFire, Compiere, Openbravo, Adempiere but those were too limited in my opinion. Basically, the trouble is that those 'Java' based ERP don't rely on true object oriented modeling since the ground up, some of them being even more SQL based then really Java based. I could explain in deep details why, but this is beyond the scope of this post.

So my conclusion was that even if I needed to learn Python, I would get the work done faster with OpenERP than with any of those existing Java based ERP's. My experiments proved me that I was right. With OpenERP, extending the relational model, the forms and making it fit to my needs was faster than with any of the other tried ERP's, even while being a Python noob. One year later, with a few successful implementations behind me, I'm only recommending it more than ever.


But wouldn't it be great to port OpenERP on the Java platform?

The benefits of porting OpenERP on Java are beyond the scope of this post. Still, here is a short list:

1. Noticeable speed up. Even if the Python layer peaks up at 40% of the CPU load under high concurrent loads, getting twice as fast would be noticeable. If Jython get as optimized as JRuby which is 2 to 5 times faster than C Ruby, we will go there.
2. Real multithreading and less memory use under huge loads (CPython scales using process and sharing nothing accross runtimes because it has a Giant Lock in its interpreter, much like PHP or Ruby). The expected benefit there is much like what benchmarks prove for heavily loaded JRuby on Rails applications.
3. One click installation on lots of hardwares (imagine how easy it will be to sale to large companies when you will say it's only a .war you pu on your Tomcat server).
4. Penetration in large companies where Java tends to rule more than Python
5. Easier and solid cross database support thanks to the unified JDBC API.
6. Larger community for OpenERP. OpenERP is certainly the open source ERP with the largest active open source community. But just imagine how large it could get when you managed to connect with the Java community, telling them: hey, we are somewhat Java based too. If you know Java you'll be able to leverage those skills to get the job done in OpenERP. Again, JRuby proved here that connecting communities was possible.
7. Possibly larger fundings and exposure for OpenERP. Openbravo certainly had the large fundings it had by playing on its Java image which as a broad acceptance in the enterprise world.
8. And the best of all: cross language implementation: by leveraging Jython, you would be able to call the best existing Java lib (there are some good ones like JDBC, JCR, JMX, JMS, ESB's, SOAP...), but also externalize some code pieces where speed is critical to Java, meaning an easier way to reach C speed (a warmed up Java6 runs at C speed and sometimes faster) than writing C bindings.
9. Jython will probably ends up implementing the MOP (Meto Object Protocol) that makes it possible to share OBJECTS between JVM based languages such as JRuby, Javascript, Scala, Clojures, Groovy... Meaning that more people could adapt OpenERP to meet their needs using the language they already master. That means you could code OpenERP modules in Ruby for instance and that's not a small thing, while preserving backward compatibility. Of course, published modules would have to keep beeing closely controlled, but at least one shot veticalization modules could offer more options.
10. Because it's fun and we can do it.

What does it take?
Well, Jython is really alive again. Notice that Microsoft hired the orginial Jython creator to create Iron Python on the .Net platform. Next, by 2008, Sun Microsystem hired the two Jython leads, Ted Leung and Frank Wierzbicki to make it Python a first class citizen on the Java platform again. Espcially, JRuby recently proved that the JVM was able to run dynamic languages faster than their native C interpreter that don't come up with such a sophisticated virtual machine. So in theory the future is bright. A 2.5 Python compliant Jython is expected by February and the current trunk largely reflecting it already.

Still, the trouble, comes with native libraries. Since Python tends to be somewhat slow, Pythonistas tend to back lot's of Python libraries by C extensions to provide extra speed. The trouble is that the Jython interpreter, sandboxed in its virtual machine environment can't invoke the same C extension, mostly because it doesn't work the same at the lowest levels.

In some places, OpenERP uses such libraries. Some of them are psycopg2, mx.DateTime, libxml2, libxslt. Overall there aren't too many fortunately so that's why this shouldn't be too hard to have a full blown OpenERP running on the JVM. The common strategy here is to set up a wrapper over existing Java libraries in place of those C extensions. Also notice that in the near future, Jython might also support CTypes, a standard way of building C extensions for Python. This is largely because Jython is benefiting here from the fantastic JRuby work of Wayne Meissner around JFFI (Java Foreign Fuction Interface). Other synergies exist, like the Da Vinci Machine, or Invoke Dynamic bytecode instruction that would help the JVM speeding up dynamic languages while optimizing memory usage.



Current status:
After some two days of heavy hacking, I'm getting:

• OpenERP server starting powered by the last Jython Java based interpreter, backed by the regular JDBC Postgres driver over a standard Java JNDI database connection pooling, instead of Pyscopg2.
• It answers most of the webservices calls, be it from the clients or from the webservice API. The largest thing that isn't working here is datetime operation that are using the mx.DataTime library that isn't yet fully supported.
• Also, views don't work yet (the fields_view_get method). This is due the current XML and XPath limited support. Everything need is available on the Java plateform, but it should be wrapped properly to fake the Python API OpenERP is expecting there.
  

Next stages:

• I guess that faking the required xpath and xml API would be great. That shouldn't be that hard given that OpenERP only use a few things in those API. We should only wrapp them over Java libraries such as Xalan.
• As for the mx.DateTime trouble, the OpenERP team said they are ready to move away from it. Indeed mx.DateTime has a bug with dates before 1970. That's why the Tryton fork moved away form it, proving the thing is possible (they only use it marginaly for parsing, but alternative can be found). Advised by Jim Baker from Jython, it appears that the standard python datetime, datetime.timedelta and the http://labix.org/python-dateutil library might be used instead. So aside from helping getting rid of mx.DateTime, we probably won't have much work here.
• Once all that is working, the Java based OpenERP server will already be in pretty good shape to be used in production.
• Of course, ideally we would package the whole thing within a standard J2EE war package and serve it with a standard servlet container such as Tomcat or Glassfish. The idea there is to write a servlet connector that will use standard Java servlet instead of the python SimpleXMLRPCServer. Then we would route HTTP request to a pool of Jython runtimes and the appropriate OpenERP server layers, much like others do with Django on Jython or the Glassfish JRuby on Rails gem supported by Sun Microsystem.
• Once performance starts to proves better than CPython (Jython and JRuby guys are expecting this to happen by 2009 already) and once large companies show interrest in deploying OpenERP over their existing Java stack, may be the OpenERP team starts to support it officially and provide alternative Java based layers to increase performance even more or provide extra features (like SOAP, JMS async messaging, ESB like Mule or ServiceMix, a REST layer, JMX remote monitoring, OpenTerracotta clustering...)
  

Steps to follow to test the current Jython powered version:

Requirements:

1. you should know how to start a regular OpenERP v5 server
2. you should have an existing OpenERP v5 database to test again
3. you should have Java installed (1.6 advised)
   

First you have to grab a recent Jython interpreter. Make sure you have a recent version of Java installed (1.6 advised) and then grab Jython:
get a fresh version of Jython, and build it:


$ svn co https://jython.svn.sourceforge.net/svnroot/jython/trunk/jython/ jython-dev
$ cd jython-dev
$ ant

now, put the jython-dev/dist/bin/jython command in your path.
now if you type

$ jython

that should bring you a Python 2.5, java based commande line interpreter.

Now grab my public branch of the OpenERP server:

$ bzr branch lp:~rvalyi/openobject-server/trunk-java-jython


As for the addons, you can use your regular OpenERP v5 addons, or grab them from here:

$ bzr branch lp:openobject-addons


Now open the trunk-java-jython/bin/tools/config.py and make sure you properly set up the database connection params and you addons path location.
May be it's better to leave the db_name to False so it will load all the features lazily when requested.


you can already see what happens if you:

$ cd trunk-java-jython/bin
$ jython openerp-server.py


You'll probably have errors because we didn't properly set up some required libraries.
So it's time to copy paste a few libraries from our regular Python path to our Jython path:
you can copy/paste the following directories:
pychart, pytz, reportlab
from
/user/lib/python2.5/site-packages/ (or whatever you Python sys.path)
to [...]/jython-dev/dist/Lib

There is one more catch though. Currently, there is bug in Jython preventing the reportlab lib to load fully. This is because font listings in the pdfbase/_fondata.py are just too large for the JVM spec to fit in a single Java method. The Jython folks are aware of that bug but it's low priority: see http://bugs.jython.org/issue527524
Meanwhile, helped by the fellow Charles Headius Nutter from the JRuby Sun team who faced similar issues implementing JRuby, I patched the file to make reportlab works in Jython. It's only a wrapping of large list instantiations and doesn't remove any feature. I submitted it to the reportlab developers and hope to see it included waiting for a Jython fix.
So in any case, for now, you should just move the _fontdata.py file provided in the trunk-java-jython branch and copy it in place of the reportlab/pdfbase/_fontdata.py file of your Jython reportlab installation.

Now you should be able to start you OpenERP server on Jython. Look at the following logs on my machine. Then I connected using XML/RPC with my GTK client (in that development version I'm printing all the requests, you could remove those print of course):

rvalyi@rvalyi-laptop:~/DEV/openobject_trunk/openobject-server-jython/bin$ jython openerp-server.py
[lun. févr. 02 2009 02:41:22] INFO:server:version - 5.0.0
[lun. févr. 02 2009 02:41:22] INFO:server:addons_path - /home/rvalyi/DEV/openobject_trunk/openobject-addons
[lun. févr. 02 2009 02:41:22] INFO:server:database hostname - localhost
[lun. févr. 02 2009 02:41:22] INFO:server:database port - 5432
[lun. févr. 02 2009 02:41:22] INFO:server:database user - openerp
[lun. févr. 02 2009 02:41:22] INFO:objects:initialising distributed objects services
WARNING; Python Imaging not installed, you can use only .JPG pictures !
[lun. févr. 02 2009 02:41:32] INFO:web-services:starting XML-RPC services, port 8069
[lun. févr. 02 2009 02:41:32] INFO:web-services:starting NET-RPC service, port 8070
[lun. févr. 02 2009 02:41:32] INFO:web-services:the server is running, waiting for connections...
list
()
-------------
[lun. févr. 02 2009 02:41:40] INFO:dbpool:Connecting to template1
executing the following DB query:
select datname from pg_database where datdba=(select usesysid from pg_user where usename='openerp') and datname not in ('template0', 'template1', 'postgres') order by datname
query passed!
[lun. févr. 02 2009 02:41:40] INFO:dbpool:Closing all connections to template1
['jython', 'openerp']
server_version
()
-------------
5.0.0



So the GTK client can connect to the Jython powered server and list the available databases for instance.
But if I try to really connect to the database and go further here I get an error unfortunately:

[...]
SELECT ir_act_window_group_rel.gid,ir_act_window_group_rel.act_id FROM ir_act_window_group_rel , res_groups WHERE ir_act_window_group_rel.act_id in (1) AND ir_act_window_group_rel.gid = res_groups.id order by res_groups.name offset '0'
query passed!
{'view_id': (1, u'ir.ui.menu.tree'), 'src_model': False, 'view_ids': [], 'context': u'{}', 'view_type': u'tree', 'auto_refresh': 0, 'usage': u'menu', 'res_model': u'ir.ui.menu', 'domain': u"[('parent_id', '=', False)]", 'name': u'Menu', 'id': 1, 'view_mode': u'tree,form', 'target': u'current', 'views': [(1, u'tree'), (False, u'form')], 'limit': 80, 'type': u'ir.actions.act_window', 'groups_id': []}
execute
('jython', 1, 'admin', 'ir.ui.view', 'read', [1], ['model', 'type'], {'tz': False, 'active_ids': [], 'lang': 'en_US', 'active_id': False})
-------------
executing the following DB query:
SELECT "model","type",id FROM "ir_ui_view" WHERE id IN (1) ORDER BY priority
query passed!
[{'id': 1, 'model': u'ir.ui.menu', 'type': u'tree'}]
execute
('jython', 1, 'admin', 'ir.ui.menu', 'fields_view_get', 1, 'tree', {'tz': False, 'active_ids': [], 'lang': 'en_US', 'active_id': False})
-------------
executing the following DB query:
SELECT arch,name,field_parent,id,type,inherit_id FROM ir_ui_view WHERE id='1' and model='ir.ui.menu'
query passed!
executing the following DB query:
select arch,id from ir_ui_view where inherit_id='1' and model='ir.ui.menu' order by priority
query passed!
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[01]: Traceback (most recent call last):
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[02]: File "/home/rvalyi/DEV/openobject_trunk/openobject-server-jython/bin/osv/osv.py", line 60, in wrapper
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[03]: except orm.except_orm, inst:
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[04]: File "/home/rvalyi/DEV/openobject_trunk/openobject-server-jython/bin/osv/osv.py", line 120, in execute
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[05]: cr.commit()
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[06]: File "/home/rvalyi/DEV/openobject_trunk/openobject-server-jython/bin/osv/osv.py", line 112, in execute_cr
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[07]: File "/home/rvalyi/DEV/openobject_trunk/openobject-server-jython/bin/osv/orm.py", line 1082, in fields_view_get
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[08]: doc = dom.minidom.parseString(encode(result['arch']))
[lun. févr. 02 2009 02:44:30] ERROR:web-services:[09]: NameError: global name 'dom' is not defined




So yeah, not everything is working yet, and especially the view layer don't work yet because we didn't provide appropriate wrappers for the xml/dom and xml/xpath Python modules used by OpenERP.

The same goes withe the web-client (eTiny), it can list the databases but won't show any view properly yet.

Still, more something interesting is that webservices, which only care about the model and controller layers are already working quite well. See yourself, in an standard python or jython console, I can for instance read all the info related to a given product (here with id 1):

>>> sock = xmlrpclib.ServerProxy('http://localhost:8069/xmlrpc/object')
>>> sock.execute("my_test_base", 1, "admin", 'product.product', 'read', [1])
[{'warranty': False, 'property_stock_procurement': [5, 'Procurements'], 'supply_method': 'buy', 'code': False, 'list_price': 38.25, 'expected_margin_rate': 0.0, 'pricelist_purchase': 'Default Purchase Pricelist (0.00) : 25.50\n', 'incoming_qty': 0.0, 'weight_net': False, 'standard_price': 25.5, 'cost_method': 'standard', 'active': True, 'price_extra': 0.0, 'mes_type': 'fixed', 'uom_id': [1, 'PCE'], 'uos_id': False, 'ean13': False, 'default_code': False, 'type': 'service', 'property_account_income': False, 'qty_available': 0.0, 'sales_gap': 0.0, 'id': 1, 'expected_margin': 0.0, 'uos_coeff': 1.0, 'virtual_available': 0.0, 'seller_delay': 1, 'total_cost': 0.0, 'purchase_ok': True, 'date_from': '2009-01-01', 'property_stock_account_output': False, 'track_outgoing': False, 'company_id': [1, 'Espace Loggia'], 'product_tmpl_id': [1, 'Onsite Senior Intervention'], 'state': False, 'loc_rack': False, 'pricelist_sale': 'Public Pricelist (0.00) : 38.25\n', 'uom_po_id': [1, 'PCE'], 'price_margin': 1.0, 'price': 0.0, 'property_stock_inventory': [4, 'Inventory loss'], 'loc_case': False, 'sale_avg_price': 0.0, 'description': False, 'track_incoming': False, 'property_stock_production': [6, 'Production'], 'purchase_avg_price': 0.0, 'weight': False, 'supplier_taxes_id': [], 'volume': False, 'normal_cost': 0.0, 'outgoing_qty': 0.0, 'dimension_type_ids': False, 'date_to': '2009-12-31', 'procure_method': 'make_to_stock', 'sale_num_invoiced': 0.0, 'variants': '', 'partner_ref': 'Onsite Senior Intervention', 'loc_row': False, 'purchase_num_invoiced': 0.0, 'sale_ok': True, 'rental': False, 'packaging': [], 'sale_delay': 7.0, 'name': 'Onsite Senior Intervention', 'total_margin_rate': 0.0, 'description_sale': False, 'property_account_expense': False, 'categ_id': [8, 'All products / Sellable / Services / Onsite Intervention'], 'invoice_state': 'open_paid', 'property_stock_account_input': False, 'track_production': False, 'sale_expected': 0.0, 'lst_price': 38.25, 'taxes_id': [], 'dimension_value_ids': [], 'produce_delay': 1.0, 'seller_ids': [], 'description_purchase': False, 'turnover': 0.0, 'purchase_gap': 0.0, 'product_manager': False, 'total_margin': 0.0}]




OK, enough said for now. I'll try to post updates on the dedicated Launchpad blueprint: https://blueprints.launchpad.net/openobject-server/+spec/jython-support-as-jython-improves
Don't hesitate to contact me if you want to push this work further.

Raphaël Valyi.

Java 7 build 44 improves jar build speed a lot indeed

Hi,

from the changelog of jdk7 build 44, one can read that they improved on the speed of the jar task.

Indeed, I can confirm this for building JRuby which is quite a large project:

Before, Java 7 build 43:
>ant-jar complete
[...]
BUILD SUCCESSFUL
Total time: 1m30 seconds


Now, Java 7 build 44:
>ant-jar complete
[...]
BUILD SUCCESSFUL
Total time: 56 seconds


Quite enjoyable indeed!

OLAP component: Mondrian+JPivot or Flex OLAPDataGrid ?

Recently I've been spending a few hours digging into OLAP cube components (a special table to analyse large and multi-dimmentionnal data in Business Intelligence). I wanted to produce a nice demo with an OLAP cube plugged to the OpenERP (by far the best open source ERP) database.

I actually saw a guy demoing such an OLAP Flex component along with Openbravo ERP (looking nice but the details were provided): http://opensourceerpguru.com/
Anyway I just wanted to achieve the same but using OpenERP (I feel much more comfortable with it's elegant and efficient architecture, not to tell about the features nor the business model) this time and eventually JRuby on Rails, my best Swiss knife to pull the data to the OLAP viewer.

So at first I've been stunned by the OLAP Flex component (called OLAPDataGrid) . It looks really nicer than the old fashion Mondrian JPivot. So I decided to give it a try. First time with Flex and back to the half open source crapp since long ago. So I had to follow all the Adobe crapp flow: create a fucking account, read all their commercial crapp, agree with their whatever license and finally download the stuff and start playing with it. Then I remarked that all my FlexBuilder nice OLAP samples were coming with a "Flex Data Vizualisation Trial" watermark. OK, time to remeber, FlexBuilder is not open source yet, so let's go with the Flex SDK, back to the Adobe legacy crapp, download again and try again (I heard that the SDK was open source, or sort of).

Then I tried to compile my mxml component with the following command line:

flex_sdk_3/bin$ ./mxmlc /home/rvalyi/DEV/olap_test/src/olap.mxml
Loading configuration file /home/rvalyi/Desktop/flex_sdk_3/frameworks/flex-config.xml
/home/rvalyi/DEV/olap_test/src/olap.mxml(162): Error: Could not resolve to a component implementation.

id="myMXMLCube"

/home/rvalyi/DEV/olap_test/src/olap.mxml(195): Error: Could not resolve to a component implementation.


WTF ???

Googled the error message and got the official answer from an Adobe employee on a forum here: http://www.codeverge.net/item.aspx?item=101509

The OLAPDatagrid component is available only in the Flex Builder Professional
version. For the first problem, the one where you are building a Flex + LCDS
2.5.1 project, the answer is that the LCDS 2.5.1 doesn't include the
OLAPDatagrid component and that is way you are getting the errors on runtime.

You f****** b*st*rds! you got me! So that how I lost a few hours trapped by the Adobe half open source policy, go hell!

Mondrian or Flex OLAPDataGrid?
Well, back to Mondrian and JPivot...

OK, for sure Mondrian and JPivot aren't really something optimal and I feel more like it's a bloated non HTTP compliant piece of code, but hey it's free and it just works. So until Tiny.be release their awesome open source "TinyBI framework" (for October?) I'll stick with it. I'll hardly try Flex and Flash again, I promise.

Finally I should say that I really don't know anyway how that Flex component would deal with a large database as it seems it's an in memory client side OLAP solution only. Even if it were to change, I'm not sure I would feel comfortable in feeding the right data pieces as the OLAP component requires them and finally all the existing samples don't come with drill down, slicer and rotation widgets, so I'm not sure how easily one can interact with the cube.

May this post save your time.

Orkut social network community profiling with GreaseMonkey and Rails, round one.

Hi,

I wanted to figure out some statistics about some Orkut (Google equivalent of Myspace or Facebook) social communities. I want to know the mean age, the gender rate and other things among given communities. And actually I'm getting a lot more as you'll see. The method I'm showing is very simple and can be reused for other purposes. It's automatic enough to grab profiles 15 by 15 and build a good sampling of the community, but not enough to grab ALL the profiles. Anyway, I guess Google would kick out crawlers wanting to grab all the profiles.

The challenge for collecting those data is that you need to be logged in to crawl Orkut communities. Then only you can grab information in the HTML pages if you manage to handle the navigation properly. I didn't really manage to automate all the process using the HPricot HTML parser.

Instead I went for a semi-automatic combination of GreaseMonkey scripts to grab the profiles and a Rails server to store the data. Now I only need to browse every members page of an Orkut community to get all its member profiles stored inside my database. Then I also have a rails action to export data in csv so I can open it in spreadsheet editor:


The first thing is to install the GreaseMonkey Firefox plugin.
Then you'll install the following user script name orkut_crawler.user.js:

// ==UserScript==
// @name Orkut_crawler
// @namespace http://livetribune.org/
// @description grab orkut properties
// @include *
// @exclude http://diveintogreasemonkey.org/*
// @exclude http://www.diveintogreasemonkey.org/*
// ==/UserScript==

var scripts = [
'http://localhost:3000/javascripts/orkut_crawler.js'
];
for (i in scripts) {
var script = document.createElement('script');
script.src = scripts[i];
document.getElementsByTagName('head')[0].appendChild(script);
}


What we are doing here is including the Prototype Javascript library to make it easier to grab the information using CSS selectors. I tried to paste the prototype lib directly inside the browser script but it didn't worked for some unknown reason. So anyway, this last solution works.

You can now make sure the script gets activated when you visit an Orkut page:

OK, now we need to set up our actual orkut_crawler script as well as the Rails backend.
build a simple Rails app using the ">rails orkut_crawler" command line.
You can use any database. I used the default Sqlite DB in my case.

Then create the database with that command ">rake db:create" inside the orkut crawler directory.

Now, let's make a simple persistent model to store our data:
"> ruby script/generate model item"
Now edit the db/migrate/001_create_items.rb migration file and write:

class CreateItems <>

Let's create the table: ">rails db:migrate"

Now we need to create the orkut_crawler Javascript file that'll be called by our GreaseMonkey script. make a new file called public/javascripts/orkut_crawler.js

Inside that file, you first need to copy the Prototype javascript library you'll find in public/javascripts. Then write this code at the end of the file:




/* Crawler */

function appendNewScript(src_url, id) {
var headID = document.getElementsByTagName("head")[0];     
var newScript = document.createElement('script');
            newScript.id = 'snap';
newScript.type = 'text/javascript';
newScript.src = src_url;
headID.appendChild(newScript);
}

function addTuple(line) {
    try {
    var key = line.childNodes[1].innerHTML;
    var value = line.childNodes[3].innerHTML;
    key = key.replace(" ", "_");
    key = key.replace("/", "_");
    key = key.replace(":", "");
    value = value.replace("\\", "");
    value = value.replace("\"", "");
    value = value.replace(";", " ");
    value = value.replace(":", " ");
    params += "&" + key + "=" + value;
    console.log(key, value);
    } catch(e) {}
}

var tab;

if (document.location.href.indexOf('CommMembers.aspx') > 0) {//it's a community page
        tab = $$('.listitem');
        for (var i =0; i<>
                                setTimeout(tab[i].innerHTML="<" + "iframe src='"+ tab[i].childNodes[1].href + "'/>", 100 * i );
        }
} else if (document.location.href.indexOf('Profile.aspx') > 0) {//it's a profile
    var params="";
    tab = $$('.listlight');
    for (var i =0; i< tab.length;i++) { addTuple(tab[i]); }
    tab = $$('.listdark');
    for (var i =0; i< tab.length;i++) {addTuple(tab[i]); }

    params = document.location.search + params;

    appendNewScript("http://localhost:3000/data/new" + params);//send the params back to our Rails app!
   



This code will grab the profile when you browse an Orkut page. If you are rather browsing a community page, then it will open all the profiles of the listed members of this page and thus grab those profiles.

Finally, we need to write a Rails controller that will persist the data (the 'new' action), render a global csv file ('index' action) and even tell how many profiles we have ('size' action). So edit app/controllers/data_controller.rb this way:

require 'cgi'

class DataController < ApplicationController
def new
params.delete 'action'
params.delete 'controller'
params.each_key {|key| params[key] = CGI.escape(params[key])}
puts params.inspect
if existing =Item.find_by_uid(params[:uid])
item = existing
else
item = Item.new
item.uid = params[:uid]
end
item.properties = params.inspect
if item.save
render :text => 'UPDATED' and return if existing
render :text => 'SAVED!'
else
render :text => 'ERROR!'
end
end

def size
render :text => Item.find(:all).size.to_s
end

def index
all_props = []
@items = Item.find(:all)
res = ""
@items.each do |item|
map = eval item.properties
map.each_key do |key|
all_props << key unless all_props.index key
end
end

all_props.each do |key|
res += key + "; "
end
res = res[0..-3] + "\n"

@items.each do |item|
all_props.each do |key|
map = eval item.properties
res += CGI.unescape(map[key].to_s).gsub("\n", " ").gsub("\r", " ").gsub("\r\n", "").gsub(";", " - ") + "; "
end
res = res[0..-3] + "\n"
end
render :text => res
end
end



OK, we are done.
Now make sure our Rails server is working:
"> ruby script/server"

You can also track what is going on:
"tail -f log/development.log"

Now visit some Orkuts community pages with this URL pattern:
http://www.orkut.com/CommMembers.aspx?cmm=10087467&tab=0&na=3&nst=151&nid=0


As you'll see, instead of the normal member's icons, we are now loading the members profiles inside iframes. At the same time, you can ensure in your terminal our Rails server is storing all the profiles.

Finally; look at the profile you collected:
see how many profiles you have collected: http://localhost:3000/data/size
Now let's export the data as csv (this can take a while depending how much data you stored):
in your terminal, execute:
">wget http://localhost:3000/data"
Now rename the data file into data.csv and browse it in OpenOffice for instance:



Ok, you are done. Now you can start making some statistics, but that's for round two!

Getting ruby-openid OpenID gem to work with JRuby on Rails

As you may know a few native methods aren't yet implemented in JRuby and a few ones aren't even possible to implement due to the POSIX native calls.

I really don't know where odes FileTest#chardev? method fits in, but JRuby doesn't have it right now.

So if ever you want to use the 'ruby-openid' gem in your JRuby on Rails using for instance the official wrapper, there is a workaround.
Indeed if you do nothing, either at the rake setup, either at startup, you'll get something like:

=> Booting WEBrick...
/home/rvalyi/DEV/jruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27: FileTest#chardev? not yet implemented (NotImplementedError)
from /home/rvalyi/DEV/jruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27
from /home/rvalyi/DEV/jruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27
from /home/rvalyi/DEV/jruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
from /home/rvalyi/DEV/jruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
from /home/rvalyi/DEV/livetribune/vendor/rails/activesupport/lib/active_support/dependencies.rb:496:in `require'
from /home/rvalyi/DEV/jruby/lib/ruby/gems/1.8/gems/ruby-openid-1.1.4/lib/openid.rb:1:in `new_constants_in'
from /home/rvalyi/DEV/livetribune/vendor/rails/activesupport/lib/active_support/dependencies.rb:496:in `require'
from /home/rvalyi/DEV/jruby/lib/ruby/gems/1.8/gems/ruby-openid-1.1.4/lib/openid.rb:1:in `require'
from /home/rvalyi/DEV/jruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:32:in `require'
from /home/rvalyi/DEV/jruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:32:in `require'
from /home/rvalyi/DEV/livetribune/vendor/rails/activesupport/lib/active_support/dependencies.rb:496:in `require'
from /home/rvalyi/DEV/livetribune/vendor/plugins/open_id_authentication/init.rb:120:in `new_constants_in'
from /home/rvalyi/DEV/livetribune/vendor/rails/activesupport/lib/active_support/dependencies.rb:496:in `require'
from /home/rvalyi/DEV/livetribune/vendor/plugins/open_id_authentication/init.rb:120:in `binding'


The workaround is to override the FileTest module and define a stub value for the chardev? method. That method is to return true or false. Returning always true for that useage seems to work well.

So at the VERY BEGINNING of your environment.rb, just write:

module FileTest
def self.chardev?(file_name); return true; end
def chardev?(file_name); return true; end
end


Then Open Id is going to play nice with your JRuby on Rails app. At the time I'm speaking, I'm on JRuby SVN head trunk and the String#split method is having a little bug that'll ouput a stack trace but fortunately this has no consequence on the functionality.

JRuby rocks!

migrating Livetribune.com on JRuby on Rails2.0

update: I'm here talking about problems I encountered migrating from Rails 1.2.3/1.2.4 to Rails2.0. My app has been on JRuby since almost the beginning and I had no issue with JRuby (this time at least). Being on JRuby motivated me even more to try Rails2.0 as the routing is said to be optimized by caching as I'll explain there.

The current state of JRuby (trunk) is that low level tests tend to be faster than C-Ruby but Rails is still a bit slower. Some people, included me, tend to think this might be due to the request routing of Rails being slow in JRuby. Indeed Rails routing extensively uses regexps and regexps in JRuby are still a lot slower than in C-Ruby. In fact this is because Java regex engines work with char[] whereas Ruby (including JRuby) represents strings as byte[]. So in JRuby we have to translate byte into char[] and back all the time for regexps untill somebody ports on Java a byte based regexp engine (namely the oniguruma lib).

So for a JRuby dev, it's always nice the hear Rails2.0 made some caching optimization on routing. So I wanted to try it. I didn't finish yet to port the Livetribune application (not yet in prod BTW) but I made great progress. In order to help other people in their migration I'll relate here a few tricks I had to do to make it working.

* url_for don't accept anymore symbols to point controllers. You have to write strings instead. So for instance:
map.connect ':locale/topics/:year/:month/:day/:id', :controller => :topics, :action => 'show'
became
map.connect ':locale/topics/:year/:month/:day/:id', :controller => 'topics', :action => 'show'
else rails will complain symbol :topics have no method [].

* the usefull routing_navigator plugin doesn't work anymore out of the box in Rails2.0 . This seems to be due to the self.template_root method call in the RoutingNavigatorController that doesn't exist anymore in Rails2.0. I didn't fin the work arround so I simply dropped the plugin.

* replace @base_path by ActionController::Base.view_paths whenever its used (in the AuthGenerator plugin for instance) as suggested here:
http://dev.rubyonrails.org/ticket/9689
(still I didn't get AuthGenerator fully working yet. Rails still miss its view templates)

* Since by default Rails2.0 sessions are based on a cookie store, either set it back to file store, either explicitly define a secrete that'll be share between the client browser and your server, like:
config.action_controller.session = { :session_key => "_myapp_session", :secret => '449fe2e7daee471bffae2fd8dc02313a' }
in your environment.rb


After this I had almost everything working again. Still some trouble with AuthGenerator, please provide feedback if you get this one fixed.

Also I installed that Rails 1.2.4 version before hoping it would shout for all the potential issues. It never shouted for those I just wrote about, so may be that could have done it better (or may be it's not too late to include those pointers).

Rails is very cool and Ruby is too. But it's in those kind of migration situations you'll think Java was just safer. I mean, I think half those problems would have been statically highlighted by the compiler. For the other half, let's face it you would have used some IOC injection like Spring so you wouldn't have detected it either (that the big hypocrisy of the today's J2EE world).

I still think nothing is approaching Rails in its niche, but that was just to highlight Ruby will never replace Java fully, even as a language. Rails is OK because the compiler safety is being replaced by the community checking quite effectively, but that wouldn't be true in an enterprise world for instance.

Finally I think JRuby really is the expected silver bullet, because it will allow you to closely choose where things get dynamic but unsafe (Ruby) and where thing get static and safe (Java). Moreover, the new optional Ruby type signature that's being imagined for the new JRuby compiler ( http://headius.blogspot.com/2007/09/compiler-is-complete.html )will just allow you to compile your great Ruby lib in Java and then use it from Java (as a jar bytecode) calling it through normal Java typed methods. It means you'll use safely Ruby libs whenever their author would have decided some part of its API deserves more security (and yes, a bit less agility). I mean JRuby will let you have the choice and that's great.

Also I forgot: I had no issue due to the use of JRuby (trunk) with Rails2.0.
Have fun with JRuby and Rails2.0.

Raphaël Valyi.

JRuby IT survey using Yahoo pipes

Suppose you are all convinced JRuby is the next big thing that will bring an incredible productivity to the enterprise world. What matters from now one is to track the new JRuby experiments popping all arround the world. Every day more and more people are throwing specialized Java libs into brand new web2.0 Rails applications. And there are also of course the JRuby implementation to track. Indeed great expectations, such as speed boost, optional typing, Java/Ruby tight integration, can be put into the recent compiler advances.

So what I did is a simple Yahoo pipe that will crawl the web and gather very recent stories about JRuby usage and progress. You would think you could simply use Google blog search and see the same. Well, that would be a little bit less pertinent. Indeed, contrary to Google, this pipe filters out SVN commits as well as bug reports which tend to pollute Google blog searches. By aggregating lots of sources including the JRuby core developer blogs, you are also sure you won't miss anything important.

So the pipe is there:
http://pipes.yahoo.com/pipes/pipe.info?_id=oCCxOv9w3BGq_aM_1vC6Jw



And here is the output of that pipe (truncated to the 4 last entries only) thanks to Google AJAX Feed API:

Loading

An important thing you could notice is that Technorati and Delicious aren't used. Well actually the problem with those is that they provide feeds ordered by tagging history, not by publication history. So an old story could seem recent in Delicious just because somebody just tagged it.

Anyway, Yahoo pipes looks like a terrific tool for IT survey in general. Analyzing how people build pipes might also provide good semantic information to Yahoo, just like Delicious.

Have fun and feel free to provide feedback or build better clones.

Raphaël Valyi.

Hacking the moo.fx Accordion into the ultimate DHTML Accordion widget

For long, I've been looking for a good Accordion widget. First I began with the Yahoo one but unfortunately I ran into serious interference troubles when using it on the same page I was using the Google Ajax search widget.

Then I came to the Moo.fx accordion and that was the good one.
Still, this Accordion has some limitations:

1. If your page is large, your browser won't scroll properly to the selected accordion tab.
2. It would be better if the user could click on an expanded tab to collapse it back/
3. You might want to have a collapse/expand button on each tab.
4. You might want your accordion to degrade gracefully for non JavaScript enabled browsers (accessibility + SEO optimization) and have links to separate pages instead of tabs in this case.
5. You want to disable the Mootools Accordion from following those accessibility links because you just want to expand the tab instead. The default Accordion implementation really sucks to this respect.
   
6. You might want a tab CSS rollover effect.
   

I addressed all those issues for the web site I'm building now: Livetribune.com.

Issue #1:
Use the prototype scrolling feature to scroll to the expanded tab (I'm using Moo for Prototype):

myAccordion = new fx.Accordion(myLinks, myDivs, {onActive: function(toggler, element){
setTimeout("Element.scrollTo('" + toggler.id + "');window.scrollBy(0,-150)", 400);
});


Issues #2 and #3:
hack Accordion a bit to allow collapsing back any tab. And also add/remove a class name to the toggle DOM element in order to then use different CSS styles, for instance to display a different button backgound-image when to tab is collapsed or expanded.
Here is my modified Accordion class, I simply changed the showThisHideOpen function :

showThisHideOpen: function(iToShow){
var forceHide = iToShow == this.previousClick;
if (!this.options.alwaysHide){
if (forceHide)
this.previousClick = null;
else
this.previousClick = iToShow;
var objObjs = {};
var err = false;
var madeInactive = false;
this.elements.each(function(el, i){
this.now[i] = this.now[i] || {};
if (i != iToShow || forceHide){
this.hideThis(i);
$(this.togglers[i]).className = $(this.togglers[i]).className.replace(' expanded', '');
} else if (this.options.alwaysHide){
if (el.offsetHeight == el.scrollHeight){
this.hideThis(i);
madeInactive = true;
} else if (el.offsetHeight == 0){
this.showThis(i);
} else {
err = true;
}
} else if (this.options.wait && this.timer){
this.previousClick = 'nan';
err = true;
} else if (!forceHide){
this.showThis(i);
$(this.togglers[i]).className += ' expanded';
}
objObjs[i+1] = Object.extend(this.h, Object.extend(this.o, this.w));
}.bind(this));
if (err) return;
if (!madeInactive) this.options.onActive.call(this, this.togglers[iToShow], iToShow);
this.togglers.each(function(tog, i){
if (i != iToShow || madeInactive) this.options.onBackground.call(this, tog, i);
}.bind(this));
return this.custom(objObjs);
}
}


Issue #4, #5 and #6
We can consider it all together. For good accessibility and degradability, we need our accordion tooggle elements to be standards 'a' links. In that a href element, we put a link to a page that will display approximatively the same content than in the tab, possibly with a restful URL so that's good for SEO optimization.

Also, now that we have those a with their href, we are able to make a CSS rollover using the a:hover CSS pseudo selector to translate the background image of our toggle element. Remember: IE6 only accept the :hover selector on links and moreover the href of those links have to be defined for the :hover selector to apply properly.

But the catch is that if you use links with href as Mootools Accordion tooggle elements, your browser will follow the links and refresh the window instead of collapsing/expanding your accordion tabs. Ending your onActive custom function doesn't fix this nasty behavior. The only way I found was to patch the Accordion widget and add the return false; statement in the initialize function in the onclick trigger of Accordion.js:

initialize: function(togglers, elements, options){
this.now = {};
this.elements = $A(elements);
this.togglers = $A(togglers);
this.setOptions(options);
this.extendOptions(options);
this.previousClick = 'nan';
this.togglers.each(function(tog, i){
if (tog.onclick) tog.prevClick = tog.onclick;
else tog.prevClick = function(){};
$(tog).onclick = function(){
tog.prevClick();
this.showThisHideOpen(i);
return false;
}.bind(this);
}.bind(this));
this.h = {}; this.w = {}; this.o = {};
this.elements.each(function(el, i){
this.now[i+1] = {};
//el.style.height = '0';
el.style.overflow = 'hidden';
}.bind(this));
switch(this.options.start){
case 'first-open': this.elements[0].style.height = this.elements[0].scrollHeight+'px'; break;
case 'open-first': this.showThisHideOpen(0); break;
}
},


for details: have a look to Livetribune. I'm still working on this site, so please be indulgent if you are coming in a bad time. Livetribune will be ready in October.

Hope you can now build your ultimate accordion widget!

Raphaël Valyi.

Very Good Javascript lessons from Yahoo

So that's it, the web2.0 is popping everywhere all over the place and you need to make your sites sexy using Javascript and AJAX.

Then you probably feel JavaScript is a crappy language you never wanted to learn. So you keep learning bits of it as you need to. But doing this you'll probably end up reading a lot of crappy examples too and that will keep you in the vicious circle of thinking JavaScript is only a toy language.

But what if you take some 2 hours and really learn the basic correctly from Yahoo people who really know what they are doing? What if you finally learn what is that damned prototype stuff and how you can prevent libraries to collide their namespaces? I did it yesterday and I'll never regret it. I still prefer Ruby (JRuby) or Java many times over Javascript, but know at least I'll know how to code JavaScript and will be much more interested and effective in making the most of existing frameworks.

So if you can, really watch those screencasts:

• The JavaScript Programming Language
  • Part 1
  • Part 2
  • Part 3
  • Part 4
• Advanced JavaScript
  • Part 1
  • Part 2
  • Part 3

Again, I've read lot's of Javascript tutorials or even books before. But nothing approaching the clarity and effectiveness of those lessons (except may be the AJAX in Action book).

Have fun,

Raphaël

import your Google bookmarks into del.ico.us!

There are plenty sites explaining how you can export your del.ico.us tags, for example to Google Bookmarks, for instance: http://blog.persistent.info/2006/10/import-your-delicious-bookmarks-into.html
(or export your Del.ico.us tags using the Del.ico.us tool in 'settings' and then import them in Firefox or Google).

But what if you want the contrary Google Bookmarks -> Del.ico.us ?
First of all, why would you do that?
Well, despite of Google offering a richer indexing of your bookmarked entries, Del.ico.us has a number of advantages:
* Del.ico.us is really oriented toward massive tag sharing, so it really helps other people to find out good pages semantically.
* Del.ico.us really uses tags as a plebiscite system to rate the page quality of a page
* Del.ico.us gives nice JSON and GET API's allowing developpers to build semantic mashups based on social tagging.

so now you know why, here is the how to import from Google Bookmarks to Del.ico.us
1) login to your Google bookmark account.
2) go to that link: http://www.google.com/bookmarks/bookmarks.html
and save that html file somwhere on your disk.
3) now login to your Del.ico.us account
4) go to 'settings' on the top right of the page. Now select: 'import / upload' in the middle of the page.
5) now just select the file you saved from Google as the file to upload. Also you probably want to removed the 'imported' tag that's going to be added by default but that's up to you. Uploading might take some time; just come bac to your bookmarks after a minute...
6) finally, sadly Del.ico.us won't share those uploaded tags with other people. That's probably because they want to ensure the quality of the tagging before sharing any tag. So unfortunately, you would now have to share your tags one by one using the buttons in the tag list. Any javascript Firebug hack to automate this would be very welcome.

That's it folks! Keeping in sync Delicious and Google Bookmark in some way might be great.

Rails 1.2 and rb-gsl ruby math lib don't play nice together!

Hi,

so Rails 1.2 might be nice, but I got some HUGE headaches when migrating to Rails 1.2. This time, all my ActiveRecord objects were raising a "private method `equal?' called for #" exception when I was using require 'gsl' no matter were in my code. That sucks a lot because ruby is a slow language (yet powerful) so I really needed to use the C native maths (matrix stuff) functions from rb-gsl.

With Rails 1.1.6 everything was OK, but with Rails 1.2, I started to get errors like:

private method `equal?' called for #
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/active_support/core_ext/class/inheritable_attributes.rb:127:in `inherited_without_layout'
/usr/lib/ruby/gems/1.8/gems/actionpack- 1.13.2/lib/action_controller/layout.rb:185:in `inherited_without_helper'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/action_controller/helpers.rb:120:in `inherited_without_api'
/usr/lib/ruby/gems/1.8/gems/actionwebservice- 1.2.2/lib/action_web_service/container/action_controller_container.rb:84:in `inherited_without_action_controller'
/usr/lib/ruby/gems/1.8/gems/actionwebservice-1.2.2/lib/action_web_service/dispatcher/action_controller_dispatcher.rb:32:in `inherited'
./script/../config/../app/controllers/application.rb:6


The problem with ruby is that each framework attempts discretely to do its own magic by redefining existing methods. But frameworks end up crunching themselves this way. That's pretty much the same knd of trouble I had with gettext (see previous post)

After looking quite a while at the code, I had no idea what object was this Hash:0xb74e20fc object neither why ActiveSupport would care about it. Adding some debug logs into ActiveSupport, I saw that all GSL objects are being handled by ActiveSupport but again, I found no way to prevent such a nasty exception to occur.

At the end, I found a dirty compromise to continue using rb-gsl in my Rails app:

First it implies you patch ActiveSupport (1.4.1 in my case) to look if the method 'equal?' isn't private as it would just occur with rb-gsl:
add this method visibility check line 127 of
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/active_support/core_ext/class/inheritable_attributes.rb

if (!inheritable_attributes.private_methods.index('equal?')) && inheritable_attributes.equal?(EMPTY_INHERITABLE_ATTRIBUTES)

(hint: you can use that check to log the problematic 'child' object if you want to debug Rails or rb-gsl)

Second, we can't require 'rb-gsl' inside an ActiveRecord object (neither a module included in an ActiveRecord object) anymore because even if we avoid the first illegal access to the private method, a there is a second catch that would break out later: 'can't change a frozen Hash', go understand...

So you'll have to encapsulate your rb-gsl lib inside some wrapping ruby object that will contains require 'gsl' and provide ruby methods to the gsl methods you are interrested in. And eventually your controllers or ActiveRecord object will play with that wrapper to call the gsl math functions.

Yes, overall, doing that really sucks, does anyone have a better idea? Who is the culprit? Rails or rb-gsl? If rb-gsl, how modify it to make it Rails compliant again?

NB: Paul King also noticed this bug with rb-gsl:
http://rubyforge.org/pipermail/mongrel-users/2007-January/002659.html
but he could eventually add a stub empty equal? method to its problematic object. This didn't work at all in my case though.

Rails 1.2 doesn't play nice with gettex

Hi,

After migrating to Rails 1.2, under certain conditions, I had suddenly lots of trouble to save any trivial ActiveRecord object. All was working like a charm before and with Rails 1.2, I started to get that exception:
In the console, I play with a dummy ActiveRecode model with only one sample string field:

>>foo=Foo.new
>>foo.save
>>foo.save SystemStackError?: stack level too deep
from
...
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.1/lib/active_record/connection_adapters/abstract/database_statements.rb:59:in `transaction' from /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.1/lib/active_record/transactions.rb:95:in `transaction' from /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.1/lib/active_record/transactions.rb:121:in `transaction' from /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.1/lib/active_record/transactions.rb:129:in `save_without_validation' from /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.1/lib/active_record/validations.rb:752:in `save'


By under certain conditions, I mean that the bug was hardly consistent, it happened only after I my application gained some complexity (Foo excepted) and also using the auth_generator plugin.

Still, I think the problem is coming from gettext (1.9.0) that seems to not behave correctly with Rails 1.2. In any situation, removing gettext always removed that bug.

So in my case I hope gettext deveoppers will react while I'm polishing my app business logic, else I'll be forced to migrate to Globalize.

Hope this helps.

Raphaël.

Prototype 1.5 bug?, at least not backward compatible with auth_generator...

Hi,

I recently upgraded my web app to Rails 1.2 coming along with Prototype 1.5. Also, In that app, I'm using the auth_generator plugin, a wonderfull plugin allowing to create a user base + login system + right policy in a snap. But what makes it very special is that this Rails plugin can display users info in a javascript generated DOM fragment that will behave accordingly to the user specific cookie allowing you to cache all your pages statically, and that's really a big win considering how slow ruby is compared to hitting only Apache for static pages.

Ok, but this is not the point. The point is that auth_generator has got some simple Ajax requests and they do not work anymore with Prototype 1.5 at least with Firefox (2.0.0.1 on Ubuntu Linux Edgy)!
Here is an example of such a request:
new Ajax.Updater('accountinfo', 'http://localhost:3000/auth/logout', {asynchronous:true, evalScripts:true, onLoading:function(request){Element.show('ident_spinner')}}); return false;")
Nothing especiall as you can see (Or please tell me if I'm wrong).
But this freezes on a Prototype exception arround the line 916:

[Exception... "Component returned failure code: 0x80070057 (NS_ERROR_ILLEGAL_VALUE) [nsIXMLHttpRequest.setRequestHeader]" nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)" location: "JS frame :: http://localhost:3000/javascripts/prototype.js?1170853340 :: anonymous :: line 916" data: no]


I have no idea at all what should be the correct behavior, if that's a Prototype bug, a Firefox bug or an auth_generator bug.

I have no idea of what side effect this could have, but a dummy fix for me consisted in rewritting the lines arround line 916 this way:

for (var name in headers) {
try {
this.transport.setRequestHeader(name, headers[name]);
} catch (e) {
//do nothing
}
}


Hope this helps, if you have a better fix, please go on and comment.

Raphaël

Update: OK, Prototype 1.5 really bombs out with Firefox, others railers discovered the bug and they found no other fix, see here:
http://dev.rubyonrails.org/ticket/6918

Ubuntu trouble: uninitialized constant Mongrel::HttpHandler (NameError)

Hi,

Ok so Rails is the must have framework, and Mongrel the must have server. But may be you just had an error when trying to launch Mongrel on Debian and you are googling desperately for a solution.

So, if after typing:
mongrel_rails

you get:
uninitialized constant Mongrel::HttpHandler (NameError)

The reason on Debian might be your Gem package is outdated, so try to type:
sudo gem update --system

For me this upgraded Gem from 0.8 to 0.9, than I reinstalled Mongrel with:
sudo gem install mongrel --include-dependencies
sudo gem install mongrel_cluster --include-dependencie

and voilà, Mongrel is now working!

Hope this help.

PS: Viva Lula! viva Chavez! fudeu a direita! Com mas de 60% dos votos contra direita, foi uma boa goleada contra burguesia, valeu. (translation: no putsh in Brazil neither Venezuela, South America is going fine).

RIGHT WING PUTSCH ATTEMPT IN BRAZIL

I'll try here to inform people that may not know the situation one week before the presidential elections in Brazil. After having been evinced from the power in 2002, those who always ruled Brazil since its colonisation are trying everything to prevent Lula from being elected again.

Opinions pools were pretty clear since several months ago: Lula was summing about 55% of the vote intentions against less than 30% for the right wing candidate. But the oligarchy -still very powerful in Brazil- tried to biased the public opinion. Journals such as Veja are lying more than Bush, while others like the "Folha de Sao Paulo" are obviously biasing the facts against Lula. The problem is that there aren't yet any mass media to balance those partial views from journals owned by the oligarchy.

Among the most scandalous stuff, are: the national lawyers association (OAB) is trying to impeach Lula; while the government was top blame, because they bought vote from opposition politicians to gain governability, the biggest problem is that the press only persecuted the government without even persecuting those corrupted politicians from the opposition who used to be corrupted for decades. Finally one week ago, a tape proving the corruption of Jose Serra -a former rival of Lula- has been discovered. Instead of investigating this case, the press is only focused on linking Lula with irregularities when obtaining that tape, again, they are trying to impeach Lula despite the total lack of proof and its huge popularity. They are thus trying to shunt the democratic process in Brazil because they fear to loose their privileges inherited from the colonnial situation.

Lula is very popular in Brazil, it's the first president who helped the poorest of the poor of Brazil. He is hopefully going to be elected any way. But still, the putsch attempt should be denounced anyway. It's our duty to blame the PSDB party and the mass media they manipulate wherever they go (that's why I'm telling it in english).

The issue is nothing funny. While the brazilian mass media (mainly Globo) are hiding the facts, they are more people killed in 3 months in Sao Paulo than during the whole second war in Lebanon! Corrupted politicians such as Jose Serra (PSDB) are widely responsible for letting that violence run out of control!

I'm only giving my view here. Others may defend the cause better (PT web site, , blogdareeleicao) , and the good results of Lula and popularity can be verified against numbers from impartial organisms. Here are such indicators:
numbers,
details of numbers
popularity pool

Sun accepted the annoying BeanInfo lookup in XMLEncoder as a bug, vote for it!

Hi,

As I described it here, XMLEncoder is giving too much pain when marshalling javabeans in unsigned applets. I've built up a workaround framework, but still, a few BeanInfo meta classes gets looked up on the server (while they don't even exist, so it's only freezing the network and loading the server). Also I can't tell if my framework really scale to any application and if there is no side effect. If there are they would be hard to debug in such a marshalling context.

We should just be able to disable that codebase lookup. Lots of problems with applets indeed come from the code base lookup, among them: problem with ResourceBundle, Services lookup, XMLEncoder, XMLDecoder (less annoying as the workarround is fully efficient). So I reported that to Sun Microsystems and the bug has been accepted. Here is the link.

So if you find it annoying and want a fast and easy marshalling in applets, if you want a faster and smaller JGraphpad CE, please vote for that bug here:
here
(you should create an account if you don't have one).

Raph.

Applet revival: JGraphpad CE BLACKJAX applet size cut from 450K down to 110K thanks to Pack200!

Pack200 is an underestimated widely deployed java tool to speed up dramatically the download time of applets or webstart applications.

I was already aware of an other 'BLACKJAX' like applet deploying Apache Derby on the client. Then I heard its creator claimed he cut Derby from 2Mb down to 600kb using Pack200..

So Pack200 is a class compressing/deflating tool deployed along with the JRE since version 1.5 (Tiger). How it works: in short applets and webstart apps are still requesting a jar archive on the server. But on the server side, you catch the fact the a different encoding (pack200-gzip) is requested by java 1.5+ clients. When requested, you'll then return the "packed" jar version, else (JRE prior to 1.5) you'll return the normal jar archive. JRE 1.5+ webstart and applet clients will deflate the packed archive on the fly saving a huge amount of server load and bandwidth.

Of course, this transfer win is only worth the CPU overhead on the client side if your archive was large enough. Make your benchmark.

Results are here:
So what about JGraphpad Community Edition? Without plugins (but with JGraph) - that's configured as the minimal online diagram editor - JGraphpad CE is weighting about 450K. Pack200 cut down the archive to 110K which is a very big win! Frankly I didn't benchmarked the extra overhead against the transfer win, but overall the win is HUGE! Overall, the applet startups 3 times faster!

So, yes it means that JGraphpad CE which is by far a more complex app than TinyMCE or FCKEditor which are 'only' online word processors, is still something 2 times smaller to download!!! (And with our "Javascript sugar", it starts up just as fast). Really amazing.

Now consider that JGraphpad CE is architectured so that you can download some plugins in the background (until you really need them) while diagramming with the core JGraph application, it turns JGraphpad CE really credible for diagram online edition.

Limits: JGraphpad CE require java 1.4.2 at least to run. But with java 1.4.2 you'll have to download the classic jar (it's totally transparent however). Only happy java 1.5 and 1.6 users will get their first download time boosted thanks to the Pack200 compression.

Server Side details:

JGraphpad CE has been designed to be server side agnostic. It only two use standard GET and POST HTTP methods to download/upload a diagram from the server. So you can use what you want to handle your uploads. I personally use Python within the MoinMoin wiki (normal file upload feature), but you could use Java, PHP or Ruby, no problem.

Still getting the Pack200 trick properly configured is server side dependent. It's easy to find out how to do with a Java server.

For an Apache server, the trick is really easy, it's explained in that excellent article.

Finally, if you can't o don't want to bother with Pack200, just put the jar in the root of the applet codebase directory as usual and this will work.

I'll soon provide a bunch of official documentation about that new JGraphpad CE release. Don't hesitate to send your feedback.