brainart on the web

Clojure: Truthy and Falsey

2011-03-01T09:38:00.001+02:00

read about this concept in Clojure -

http://blog.jayfields.com/2011/02/clojure-truthy-and-falsey.html

Yoxos onDemand Eclipse distro builder

2009-07-31T14:24:00.001+03:00

As many java developers I migrated to new Eclipse 3.5 release named "Galileo".
Everything worked perfect till the moment when I updated Subversion plugin - Sublipse from 1.6.2 to 1.6.3

As a result I lost all the additional plugings installed over eclipse including the Subclipse.
The list of installed features shows the plugings, but nothing more. My attempt to recover the eclipse configuration failed.

I also tried to install everything from scratch, but again I got the same result. The failure was persistenty reproducable.
It seems that the new EPP update manager which is new in Galileo and supposed to be better fails.

So I decided to use the Yoxos onDemand distro builder to prepare the desired eclipse environment.
It takes me just few minitus to prepare what I wanted, plus the service give you the ability to create a profile that keeps the already distro for late download.

Finally I have everything working without dealing with the eclipse update manager.

http://eclipsesource.com/en/yoxos/yoxos-ondemand/

T5 and form component

2007-09-17T11:59:00.000+03:00

Surprise or not in Tapestry 5 there is no way to submit https request from non SSL context.

A good feature in previous release was the ability to provide connection type - http or https.

Tapestry 5 approach to override services

2007-09-05T13:50:00.000+03:00

One of the things I was not happy with early versions of tapestry framework is the ability to override behavior of components rendering.

When it comes to render strict xhtml then the only thing you can do is start overriding components one by one.

Now in tapestry 5 the strict xhtml is not supported as expected ( but promised). Probably it will be fixed latter. But till then, I found that now the overriding is much easy with IoC build-in support.

In order to render your html output as valid xhtml you may do something like this:

1. Write your own StrictMarkupModel.java that overrides:

public EndTagStyle getEndTagStyle(String element)
{
boolean isEmpty = EMPTY_ELEMENTS.contains(element);

return isEmpty ? EndTagStyle.ABBREVIATE : EndTagStyle.REQUIRE;
}

2. Write your own MarkupWriterFactoryImpl.java that returns:

public MarkupWriter newMarkupWriter()
{
return new MarkupWriterImpl(new StrictMarkupModel(), _componentInvocationMap);
}

3. Override the alias to existing service into AppModule.java:

public static MarkupWriterFactory buildStrictMarkupWriterFactory(
ComponentInvocationMap componentInvocationMap)
{
return new MarkupWriterFactoryImpl(componentInvocationMap);
}

public static void contributeAliasOverrides(@InjectService("StrictMarkupWriterFactory")
MarkupWriterFactory markupWriterFactory,
Configuration configuration)
{
configuration.add(AliasContribution.create(MarkupWriterFactory.class, markupWriterFactory));
}

end

my recent picture

2006-12-08T15:13:00.000+02:00

Strange days.

www.lingodeal.com

2006-12-04T14:09:00.000+02:00

After a few months of marketing studies and the same amount of development the www.lingodeal.com is a fact.

Now it's in his beta stage and of course still waiting for new UI skin, but it's Up.

back to my blog

2006-11-24T10:19:00.000+02:00

After one year, since my first post, I'm back again.

Crystal Reports optimization

2005-10-20T17:50:00.000+03:00

How to keep grouping on server if there is a formula in record condition?

Yesterday I spent a few hours with Crystal Reports 8.5, trying to move all important calculations in a report to Oracle server. My goal was to do all grouping on the server. With such an attitude I hoped to move all the logic to database view and to keep presentation as simple as possible.

My disappointment rises when I realized that Crystal asks for data with full SQL query when there is a formula in record condition and not with optimized query.

The problem:
When Crystal "thinks" that the server will not be able to understand its queries, it forwards the db the minimum info, and does the grouping and the elimination of records on the client.

In my example I had something like this:

if ({?Service}<>"All") then ({?Service} = {SUMMARY_DOWNLOAD.SERVICE}) else true;

Where I tried to add where clause, only if the parameter “Service” is different from string “All”.

The Solution:
Try to avoid formulas and use only parameters.
How?
Translate the formula to simple “understandable” sql condition. This approach requires modification of the record condition and DB view as well

{SUMMARY_DOWNLOAD.SERVICE} = {?Service} or {SUMMARY_DOWNLOAD.ALL_SERVICE} = {?Service}

Original oracle view:

CREATE OR REPLACE VIEW SUMMARY_DOWNLOAD AS
SELECT
"TRANSACTIONS"."DOWNLOAD_DATE",
"TRANSACTIONS"."ITEM_NAME",
"TRANSACTIONS"."FLVSIZE",
"TRANSACTIONS".ITEM_DESC
FROM
"TRANSACTIONS" "TRANSACTIONS"
WHERE
"TRANSACTIONS"."WAS_DOWNLOAD" = '1' AND
"TRANSACTIONS"."TRANS_STATUS" = 1 AND
ORDER BY
"TRANSACTIONS"."ITEM_NAME" ASC

After re-factoring:

CREATE OR REPLACE VIEW RPT_SUMMARY_DOWNLOAD AS
SELECT
"TRANSACTIONS"."DOWNLOAD_DATE",
"TRANSACTIONS"."ITEM_NAME",
"TRANSACTIONS"."FLVSIZE",
"TRANSACTIONS".ITEM_DESC,
'ALL' ALL_SERVICE
FROM
"TRANSACTIONS" "TRANSACTIONS"
WHERE
"TRANSACTIONS"."WAS_DOWNLOAD" = '1' AND
"TRANSACTIONS"."TRANS_STATUS" = 1 AND
ORDER BY
"TRANSACTIONS"."ITEM_NAME" ASC