Cobertura vs EMMA

This is a rant against the Cobertura maven integration - and to a certain extent on Cobertura also - and hopefully an objective one ;). Hopefully this'll help someone select between the two big (open source) coverage tools out there.

We've been using Cobertura at work till now and its done its job nicely - the reports look great and the maven 1.x integration, while not neat, is functional. While we knew that someday we were going to have to merge coverage data and have a single report across multiple test methods (junit, selenium tests and manual), cobertura documentation stated that this was possible and so we weren't really bothered.

Thought I'd give it a whirl and set it up - and that's when the trouble started. Atleast, with the maven integration.

First of all - there's no way to just instrument code. You can generate the report (which will instrument classes and run the tests) but if you just want to instrument classes so that the final deployable contains instrumented classes, its a no go with the maven plugin tools.

Obviously, no point giving it up there - so thought I'd just include the ant tasks and go the ant way in my maven goal. Turns out that there's no 'plugin init' kind of goal that can be called post build:start that will set up dependencies and import the cobertura ant tasks. You have to do it all yourself.  Fine - went that way too - so now my maven.xml uses the cobertura ant tasks and finally I'm able to generate an instrumented build. YIPPPPPPPEEEEEE.... or wait...lets' just make sure that this thing works...

Does it?

Turns out - no - it doesnt - so I dropped the WAR into tomcat and accessed the login page of the application and then shut down tomcat nicely. There's even a cobertura.ser created in the tomcat bin folder and I'm thinking that probably this will all work together finally...

So I go ahead, tweak my Maven.xml further with a coverage task that will merge the data from the junit runs and servlet container runs. Turn the switch on... and lo and behold...Exception reading the merged data file. Back to google and after hunting around for sometime found this Bug while merging reports

So finally I'm ready to give up cobertura and give Emma a try...and it couldnt have been better...

1. Goals are nicely setup

2. You can init the emma system with the emma:init goal and then use ant tasks if you want flexibility for doing things like merging reports.

3. The merging works :))

One sticky issue that I did come up  with was that the for the same source and test cases the coverage reported by cobertura and emma differ widely. With Cobertura, we were at 40% coverage while with EMMA, the number's up to 60% coverage - and while EMMA has some literature on how it does things - I'd be glad if someone did explain why or how the reported numbers could be so different for the same base code and unit test suite?

Tulip festival at Skagit county

We visited the Tulip festival at Skagit valley. Its hard to describe in words - and a picture's worth a thousand words - so here's a bunch of pics - let them do the talking :).

Anyway, had a lovely weekend driving up to Mount Vernon with friends and had a memorable weekend.

TulipFestival

Ninotech Path Copy 4

Ninotech Path Copy 4
Novell Cool Solutions: Cool Tool

Was looking for a shell extension to copy filenames from explorer. Thought there'd be a dime a dozen - and it turns out that
a) they have 20 other things that I dont want.
b) Its trial ware.

Finally after searching high and low, came across this and it's GREAT!

powered by performancing firefox

Production Eclipse Configuration

Part of the game of getting code out that conforms to coding standards without having to go through the "One Big spring cleaning" exercise is configuring and centralizing the tools.

At a minimum, it helps to have a central Eclipse installation that has all the tools configured and setup - so each person doesn't have to do it. Alternatively, there should be a reference set of plugins and their configuration files available in the source control repository.  Here's my eclipse configuration

Tips for using Eclipse

http://www.aspectprogrammer.org/blogs/adrian/2006/02/tips_for_using.html

Great Article - full of very very useful tips!

Firefox - not so obvious search

I discovered this - totally by accident.

In Firefox, you can use / (forward slash) to search for text OR links - and if its a link, then you can follow the link just by clicking Enter!  That is way cool - especially when you're on a laptop and cant/dont have your mouse around. I've always find it a pain to do a "link find"  - ' (single quote) and a text find - ctrl-f separately...Never knew that there was a shortcut that did both and what more - its way natural if you're used to 'less'!!

To complete the keys for Firefox mouseless browsing,

• space -  page down


• shift - space - page up

Performancing and Wordpress - initial imression - very nice!

Performancing | Firefox Add-ons | Mozilla Corporation

Performancing for Firefox is a full featured blog editor that sits right in your Firefox browser and lets you post to your blog easily. You can drag and drop formatted text from the page you happen to be browsing, and take notes as well as post to your blog.

powered by performancing firefox

Diigo - a hidden gem

If you use del.icio.us for online bookmarking and like google's notepad for online research, then suggest that you take a look at Diigo's offering. It's all those rolled in one and then some.

I've been using it for quite some time now (after trying out del.icio.us and google notepad) and I'm not budging! Recently I was doing a bunch of research online and diigo excelled!

1. Online bookmarking - will also simultaneously post to your del.icio.account


2. Firefox toolbar


3. tagging


4. Web clipping


5. Web annotation

Now to "hidden" - I've been on Diigo more than 8 months or so now - and yet I'm still to meet someone who knew about Diigo!!
Diigo rocks!

Imaging the tenth dimension

Amazing flash movie!

Great flash movie explaining dimensions 4 (time), 5, 6 all the way uptil 10. And why they stop after 10!

I've never come across a clearer explanation ever and the great visualization does the trick.

Instant messenger client utopia

GAIM...

I hate running 3 different chat clients (yahoo, msn, gtalk) on my machine - and that's just 3x memory, startup programs and useless adversting too many.

And I hate msn and yahoo's advertising that's built into their clients...esp on MSN which insists on opening a mini page on login...

Use GAIM - and do yourself a favour. Of course that's if you don't need the very specialized features :)).

Installation is a breeze and use plugins you like and avoid the bloat....The best plugins I like are guifications and text replace. Lastly, if you keep moving between machines as much as I do, then its a breeze to retain your settings between all your machines.

XSLT Analog to sysouts

I'm on a high. I've been stuck with this problem of trying to understand a HUGE xslt that operates on an even bigger XML. I sorely needed something that will let me trace through the xslt execution to understand the flow.

Tried a couple of IDEs - Stylus Studio (free edition) and Marrowsoft XSelerator. Stylus studio did a graceful exit, Xselerator went purple in the face and died a gruesome death :-(

Hmm... so after sometime I was wondering if I could annotate the XSL output with information on the templates matched it would atleast help partway. I was thinking of perl/C#/regular expressions and then suddenly the penny dropped "for each xsl:template node, include a comment with the template match/mode" - Hang on!!! looks like that sounds like a job for XSLT....

Anyway, there are a couple of quirks - the first one you hit will be when you try to output a template like this

<xsl:stylesheet version="1.0"  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" >
<xsl:template match="xsl:stylesheet" >
<!-- generate an output xsl:stylesheet node -->
<xsl:stylesheet></xsl:stylesheet>
</xsl:template>
</xsl:stylesheet>

Oops! The XSLT processor cribs (and with good reason too)! It doesn't know which xsl:template is for the current stylesheet vs which is intended to be output to the result document.There are a couple of approaches around this. One is to use xsl:element like this

    <xml:namespace prefix = xsl />
    <xsl:element name="xsl:template">
    </xsl:element>
  

But this results in enormously wordy documents. Thankfully there's a neater way out. You use something called . Basically, what it does is that it allows you to use a dummy namespace in your xslt. You set up the dummy namespace (let's say genxsl) to map to a real namespace in the result document (xsl). Then you basically use the dummy namespace in your XSLT. However, when generating output, the processor will replace all references to the dummy namespace in the result document with references to the real namespace. For ex.

<xsl:stylesheet version="1.0"  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:gen="http://www.w3.org/1999/XSL/Transform/2">
    <xsl:namespace-alias stylesheet-prefix="gen" result-prefix="xsl"/>
    <xsl:template match="xsl:stylesheet">
        <gen:stylesheet>
            <xsl:for-each select="@*">
                <xsl:attribute name="{name(.)}">
                    <xsl:value-of select="."/>
                </xsl:attribute>
            </xsl:for-each>
            <xsl:apply-templates></xsl:apply-templates>
            <xsl:if test="not(xsl:template[@name='pseudo-xpath-to-current-node'])" &gt;
                <xsl:text>
                    &amp;#10;&amp;#10;
                </xsl:text> <xsl:copy-of select="document('')/xsl:stylesheet/xsl:template[ @name='pseudo-xpath-to-current-node']"/>
                <xsl:text>
                    &amp;#10;&amp;#10;
                </xsl:text>
            </xsl:if>
        </gen:stylesheet>
    </xsl:template>
</xsl:stylesheet>

Note the usage of xsl:namespace-alias and the code for generating an xsl:stylesheet element in the result document.

I've included my efforts here - along with a simple books.xml, a books.xsl which generates a table and finally an instrument.xsl that instruments books.xsl to generate an instrumented version. Transforming books.xml with the instrumented xslt generates output that annotated with custom nodes that highlight which template got called when.

After I was mostly done with the code, I came across an article in IBM developerWorks which discusses the same topic. Rather than cover the same material again, you can find the article here. Stuff that's different is that I generate custom nodes (which I thought would be useful to view in XML IDE which allow a hierarchical display). I've also shamelessly borrowed the code to generate the Xpath of the node (part of what you see in the snippet).

I'm on a high. I've been stuck with this problem o...

I'm on a high. I've been stuck with this problem of trying to understand a HUGE xslt that operates on an even bigger XML. I sorely needed something that will let me trace through the xslt execution to understand the flow.

Tried a couple of IDEs - Stylus Studio (free edition) and Marrowsoft XSelerator. Stylus studio did a graceful exit, Xselerator went purple in the face and died a gruesome death :-(

Hmm... so after sometime I was wondering if I could annotate the XSL output with information on the templates matched it would atleast help partway. I was thinking of perl/C#/regular expressions and then suddenly the penny dropped "for each xsl:template node, include a comment with the template match/mode" - Hang on!!! looks like that sounds like a job for XSLT....

Anyway, there are a couple of quirks - the first one you hit will be when you try to output a template like this

<xsl:stylesheet version="1.0"  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" >

<xsl:template match="xsl:stylesheet" >

	<!-- generate an output xsl:stylesheet node -->

		<xsl:stylesheet>

		</xsl:stylesheet>

	</xsl:template>

</xsl:stylesheet>

Oops! The XSLT processor cribs (and with good reason too)! It doesn't know which xsl:template is for the current stylesheet vs which is intended to be output to the result document.There are a couple of approaches around this. One is to use xsl:element like this

    <xml:namespace prefix = xsl />

	<xsl:element name="xsl:template"></xsl:element>

But this results in enormously wordy documents. Thankfully there's a neater way out. You use something called . Basically, what it does is that it allows you to use a dummy namespace in your xslt. You set up the dummy namespace (let's say genxsl) to map to a real namespace in the result document (xsl). Then you basically use the dummy namespace in your XSLT. However, when generating output, the processor will replace all references to the dummy namespace in the result document with references to the real namespace. For ex.

<xsl:stylesheet version="1.0"

	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

	xmlns:gen="http://www.w3.org/1999/XSL/Transform/2">

<xsl:namespace-alias stylesheet-prefix="gen" result-prefix="xsl"/>

<xsl:template match="xsl:stylesheet">

	<gen:stylesheet>

		<xsl:for-each select="@*">

		<xsl:attribute name="{name(.)}">

		<xsl:value-of select="."/>

		</xsl:attribute>

	</xsl:for-each>

	<xsl:apply-templates></xsl:apply-templates>

	<xsl:if test="not(xsl:template[@name='pseudo-xpath-to-current-node'])" >

	<xsl:text></xsl:text>

	<xsl:copy-of select="document('')/xsl:stylesheet/xsl:template[ @name='pseudo-xpath-to-current-node']"/>

	<xsl:text></xsl:text>

	</xsl:if>

</gen:stylesheet>

</xsl:template>

Note the usage of xsl:namespace-alias and the code for generating an xsl:stylesheet element in the result document.

I've included my efforts here - along with a simple books.xml, a books.xsl which generates a table and finally an instrument.xsl that instruments books.xsl to generate an instrumented version. Transforming books.xml with the instrumented xslt generates output that annotated with custom nodes that highlight which template got called when.

After I was mostly done with the code, I came across an article in IBM developerWorks which discusses the same topic. Rather than cover the same material again, you can find the article here. Stuff that's different is that I generate custom nodes (which I thought would be useful to view in XML IDE which allow a hierarchical display). I've also shamelessly borrowed the code to generate the Xpath of the node (part of what you see in the snippet).

I love the premise of Test Driven Development - I've even used it a few times in the line of duty ;-) (I do have to admit, I've been naughty and left out the step of  seeing the test case fail a few times )...Anyway, I end up working on web applications more often than not and while you can use TDD for your class libraries, a web app is a totally different animal. The fact that you can use TDD for class libraries makes the whole thing even more frustrating - you have a bit that works for sure (the class libraries with their tests) and then you hit this piece (aspx) on which you dont have the same level of confidence.

I've been working around it making sure that pages generate nice logs, so that during development, whenever I find a sticky piece, I put in an additional log statement. This thing works but at best is a poor cousin to automated testing ala nunit.

Enter NunitAsp - it promises to do for web applications what nunit does to class libraries - pretty stiff goal indeed! I've looked at this piece about an year ago for a similar project but had to decide against its use after going through the feature list. As a result, though I understand the aims, I havent got my hands into it. These days' I'm planning to do a dive-deep into it - just to make a more diligent evaluation if it'll actually work.

I love the premise of Test Driven Development -...

I love the premise of Test Driven Development - I've even used it a few times in the line of duty ;-) (I do have to admit, I've been naughty and left out the step of  seeing the test case fail a few times )...Anyway, I end up working on web applications more often than not and while you can use TDD for your class libraries, a web app is a totally different animal. The fact that you can use TDD for class libraries makes the whole thing even more frustrating - you have a bit that works for sure (the class libraries with their tests) and then you hit this piece (aspx) on which you dont have the same level of confidence.

I've been working around it making sure that pages generate nice logs, so that during development, whenever I find a sticky piece, I put in an additional log statement. This thing works but at best is a poor cousin to automated testing ala nunit.

Enter NunitAsp - it promises to do for web applications what nunit does to class libraries - pretty stiff goal indeed! I've looked at this piece about an year ago for a similar project but had to decide against its use after going through the feature list. As a result, though I understand the aims, I havent got my hands into it. These days' I'm planning to do a dive-deep into it - just to make a more diligent evaluation if it'll actually work.

For the most part, I find ASP.NET far more easier to use than Java. But the ONE BIG THING where I've found ASP.NET sorely lacking is in the support for page templates.

Page templates, if you need to brush up, allow you to define common layout and contents for a web site. Furthermore, once defined, its easy to change the layout and or move your default items around the place.

Basically, what you need is to be able to define a template page with the different areas (header, left pane, main content, footer etc). So the template page controls what is shown where. In addition, you also define the default content for all these areas.

Now each page in the application just overrides the content for the main area (assuming that the defaults are fine for the rest of it). WOW!!!

Java's had this quite some time - Jakarta Struts has something called Tiles which does exactly this.

For .NET, as I mentioned, the need's going to be fulfilled with v2.0 of ASP.NET. Meanwhile, if you feel the idea's great and there's no point in waiting for v2.0, release, do take a look at MasterPage as www.asp.net control gallery. Do note that since the asp.net team has released this control, there's a good chance that most of the features will end up in asp.net 2.0.

There are a few shortcomings of the control though - you'll get a hang of them if you read the posts. Paul Wilson has a version which overcomes these - and best of all, he releases the control with source :). You can find it here.

For the most part, I find ASP.NET far more easi...

For the most part, I find ASP.NET far more easier to use than Java. But the ONE BIG THING where I've found ASP.NET sorely lacking is in the support for page templates.

Page templates, if you need to brush up, allow you to define common layout and contents for a web site. Furthermore, once defined, its easy to change the layout and or move your default items around the place.

Basically, what you need is to be able to define a template page with the different areas (header, left pane, main content, footer etc). So the template page controls what is shown where. In addition, you also define the default content for all these areas.

Now each page in the application just overrides the content for the main area (assuming that the defaults are fine for the rest of it). WOW!!!

Java's had this quite some time - Jakarta Struts has something called Tiles which does exactly this.

For .NET, as I mentioned, the need's going to be fulfilled with v2.0 of ASP.NET. Meanwhile, if you feel the idea's great and there's no point in waiting for v2.0, release, do take a look at MasterPage as www.asp.net control gallery. Do note that since the asp.net team has released this control, there's a good chance that most of the features will end up in asp.net 2.0.

There are a few shortcomings of the control though - you'll get a hang of them if you read the posts. Paul Wilson has a version which overcomes these - and best of all, he releases the control with source :). You can find it here.

The ASP.NET validation summary is great for displaying all the errors in the page. It would be nice though to be able to use a validation summary to display errors that occur on the server side.

A typical scenario is when you have a page that does a search and then displays the results of the search. For the case where no results are found, it would be nice to be able to display the results in our custom validation summary control. It takes away the need to handle the display of the error message in a validation summary control.

This is what you can do about it - implement the IValidator class

public
class CustomErrorMessage:IValidator
    {
        privatestring message;
        public CustomErrorMessage()
        {
            //
            // TODO: Add constructor logic here
            //
        }
        #region IValidator Members

        publicvoid Validate()
        {
            // TODO: Add CustomErrorMessage.Validate implementation
        }

        publicbool IsValid
        {
            get
            {
                returnfalse;
            }
            set
            {
                
            }
        }

        publicstring ErrorMessage
        {
            get
            {
                
                return message;
            }
            set
            {
                this.message = value;
            }
        }

        #endregion
    }

And here's code to use the validator at runtime in response to a server side error.

CustomErrorMessage msg = new CustomErrorMessage();
msg.ErrorMessage = "No rows found";
ServerErrors.Visible =true;
ValidationSummary1.Visible = false;
Page.Validators.Add(msg);

Page.Validate();

The ASP.NET validation summary is great for displaying all the errors in the page. It would be nice though to be able to use a validation summary to display errors that occur on the server side.

A typical scenario is when you have a page that does a search and then displays the results of the search. For the case where no results are found, it would be nice to be able to display the results in our custom validation summary control. It takes away the need to handle the display of the error message in a validation summary control.

This is what you can do about it - implement the IValidator class

public
class CustomErrorMessage:IValidator
    {
        privatestring message;
        public CustomErrorMessage()
        {
            //
            // TODO: Add constructor logic here
            //
        }
        #region IValidator Members

        publicvoid Validate()
        {
            // TODO: Add CustomErrorMessage.Validate implementation
        }

        publicbool IsValid
        {
            get
            {
                returnfalse;
            }
            set
            {
                
            }
        }

        publicstring ErrorMessage
        {
            get
            {
                
                return message;
            }
            set
            {
                this.message = value;
            }
        }

        #endregion
    }

Been tinkering with getting a nice paging algorithm out. To get a basic hang of the problem, do take a look at

Many ASP developers create their own search engines that return back the results to the web browser one page at a time

Do take a look at the second query given. I've modified it a little bit so that you can sort by a given field and removed a bit of the cruft (the au_lname like '%A%' bit). Here the table used is called Pager - with a column called Name.

Some of my bare bones requirements for a paging system are:

1. Should allow sorting

2. Should not impose any requirements on the table schema/ resultset.

3. Should be done on SQL Server as much as possible. Definitely not default paging that results in all rows being sent to the middle layer.

4. Ideally, should not require dynamic queries. (Though note that this conflicts with 1 & 3 as these two requirements almost make dynamic queries mandatory).

5. Should not use temp tables.

declare @pagenum int
declare @pageSize int

set rowcount  @pagesize

select * 
   from Pager P
where
    (select count(*)
    from Pager P2
    where P2.Name <= P.name) > @pagesize * @pagenum
order by
       p.name

 

The ASP.NET validation summary is great for dis...

The ASP.NET validation summary is great for displaying all the errors in the page. It would be nice though to be able to use a validation summary to display errors that occur on the server side.

A typical scenario is when you have a page that does a search and then displays the results of the search. For the case where no results are found, it would be nice to be able to display the results in our custom validation summary control. It takes away the need to handle the display of the error message in a validation summary control.

This is what you can do about it - implement the IValidator class

public
class CustomErrorMessage:IValidator
    {
        privatestring message;
        public CustomErrorMessage()
        {
            //
            // TODO: Add constructor logic here
            //
        }
        #region IValidator Members

        publicvoid Validate()
        {
            // TODO: Add CustomErrorMessage.Validate implementation
        }

        publicbool IsValid
        {
            get
            {
                returnfalse;
            }
            set
            {
                
            }
        }

        publicstring ErrorMessage
        {
            get
            {
                
                return message;
            }
            set
            {
                this.message = value;
            }
        }

        #endregion
    }

And here's code to use the validator at runtime in response to a server side error.

CustomErrorMessage msg = new CustomErrorMessage();
msg.ErrorMessage = "No rows found";
ServerErrors.Visible =true;
ValidationSummary1.Visible = false;
Page.Validators.Add(msg);

Page.Validate();