should i use git over subversion

I’ve heard good things about GIT and decided to see whether to use it over Subversion for a project.

The first few benefits of GIT I encountered:

  • Distributed nature/connectivity – you have access to the whole repository even if you don’t have network/internet connectivity
  • Bisect command – to see when a bug introduced
  • Disk space – GIT compresses data well so the whole repository doesn’t take up as much space as one would expect

Disadvantages of GIT:

  • Since it is so new, the tooling isn’t as mature as I’d like it to be before relying on a project.  (This may not be a project for work, but it’s not just version control on my own machine either.)  See below about GIT clients.

Things I’m not sure about yet:

  • Branch handling – “You can commit to your local repository without messing up things for your co-worker” – This seems like it flies in the face of continuous integration.  I want people to be committing to a shared space frequently so we find out about integration issues as early as possible.  This sounds like “developer branches” which I feel are a step backwards.
  • Audit – Where is the official copy?  If everyone has a copy of the repository, which is the official copy for auditing/protection against hackers/etc.

Git clients

  1. Command line.  The command line looks solid.  There is even a command comparison if you use Subversion.  You just download and install.
  2. GUI. (SmartGit) – While this is still in beta, it seems ready.  The official statement is “SmartGit is in pre-release state, but we consider its feature set (for the first release) rather complete. ”  It has been in public milestone status since August (2009.)  When I installed it, SmartGit said it “expires 12/30/09”.  I suppose this is so you don’t stay on the milestone build too long.
  3. Eclipse plugin. (EGit) – While you can get this from the Eclipse update site, it says “are only made available to help the EGit development team use the plugin to develop itself. ”  I tried anyway to see what would happen.  It installed, but I couldn’t find a perspective/view that had to do with GIT.

While the GUI is available for all operating systems (Windows, Linux, Mac’s OS X, etc), it is still technically in beta.

My conclusion

Git looks like it will be really good one day.  For playing with a version control tool. I think it is great.  However, I don’t think it’s a point to recommend using for the project I was thinking of for several reasons.  The two main ones are:

  • The GUI support isn’t there yet.  This project has a lot of new developers on it so I think a good GUI is critical.
  • I’m not yet comfortable with the idea of source control being so distributed.  If something is on one person’s machine, it doesn’t really exist.  Just like “if it isn’t in SVN it isn’t done.”

Further reading:

See the official GIT/SVN comparison

“head first” style aria

I attempted to give a Head First style speech at the Toastmasters humorous speech competition. As a moderator at JavaRanch, it seemed fitting to put a transcript of one iteration online. While it changes a bit each time I give it, this is the idea.. Shown here with a bit of organization.

This was given to a largely non-technical audience.   For the more technical readers here, ARIA actually has four levels: off, polite, assertive and rude.  This article on ARIA is an excellent read.  My audience tells me the concepts were memorable and the speech was funny.  So I guess I accomplished my goal.  I did win at my club and get to go on to the next level.  Which gives me the chance to give this speech in front of people I don’t know.

You no longer have to imagine the sock puppets :).  I had two – one for the browser and one (with glasses) for the screenreader.
screenreader puppet

Anyway, here we go:


Introduction
Me: When you think of technology, do you think of humor?  I do.  My goal is to teach you about a technical topic called ARIA – Accessible Rich Internet Applications.  Boring?  Just you wait.  I brought sock puppets.

Welcome the characters
Me: We all know what a browser is.  We use it every day to browse the web.  I’ll let you imagine that this sock puppet is IE 7.  You may not know what a screenreader is.  Imagine you can’t see the screen.  What does our browser friend here look like?  Well, the screenreader reads the words in the browser to you.  The glasses remind us of reading so it will be easy to remember that this guy is the screenreader.  Lets listen in on how things worked up until now.

Scenario 1 – Before ARIA
Browser: I’m IE 7.  Who are you?
Screenreader: I’m a screenreader product called Jaws.
Browser: Ah!  A shark!  And I can’t see my users!  A shark ate my users!
Screenreader: Stop being so dramatic.  Your user is write here – safe and sound.  I help your user.
Browser: My user is just find without your help.
Screenreader: Want to be IE 7?  Watch what happens when a blind or vision impaired users tries to fill out a form without a standard called ARIA.
Browser: I’ll set the scene.  It was a dark and stormy night.
Screenreader: Get on with it.  I can’t read to the user until you get around to rendering the page.
Browser: Fine.  Here’s your page.
Screenreader: Ok.  User? I’ve got some questions on a form for you.  <hum as they go back and forth>
Browser: Uh oh.  The user entered a bad country.  I know because I checked with the website while the user was filling out the form.  I know!  I’ll put a big red message on the screen.  Surely the user will see that.
Screenreader: <back to humming>.  Submit.  My masterpiece.  All done now – time for a nap.
Browser: Wait a minute!  The country is still invalid.  Jaws – can sharks swim with their eyes close?  You’re falling asleep on the job.  I told you there was a message.
Screenreader: Did not!  You place a secret message and didn’t tell me it was there.  That’s like putting a note in a dictionary in a basement in Europe and claiming I should have seen it.
Browser/ Screenreader: Did not!  Did too!  Did not!  Did too!

Me: All right guys. Break it up.  Luckily this is a thing of the past.  Let’s upgrade to IE 8 and see how it looks now.  Ready IE 8?

Scenario 2 – Urgent Message with ARIA
Browser: Yes!  I’m all bright, shiny, new and upgraded.  My father was IE 7.  Parents are so backwards!  I’ll set the scene.  It was a dark and stormy night.
Screenreader: Just like you father.  Get on with it.
Browser: Where’s the fire?  Here’s your page.
Screenreader: <hum to user while fill out form>
Browser:  Uh oh.  The website says we can’t ship a book to North Korea.  I know!  I’ll set the rude ARIA property to tell the user.
Screenreader: I see the rube property is set.  The sky is falling!  The sky is falling!  I must tell the king, I mean the user.  User – Abort!  Abort! Urgent message – no books can go to North Korea.
Screenreader: Browser, that was a close one.  But we save the day – and the user – thanks to ARIA.  Remember what that stands for?
Browser: Yeah.  Accessible rich internet applications.  Accessible.  That would be you screenreader – reading to the user.  Internet Application.  That’s a website where we can fill out forms.  And rich.  That must mean the website has a pot o’gold.
Screenreader: Not quite.  Rich means dynamic and interactive.  Like gmail.  You can do things without reloading the whole page.

Interlude
Me: As you can see, IE 8 support is much better than IE 7.  But does this mean we have to interrupt the user for ever little thing.  Seems distracting.  T-O-P- Wait!  I have something unimportant to tell you. !  Let’s watch.  Browser?

Scenario 3 – Informational Message with ARIA
Browser: I’ll set the scene.  It was a dark and stormy night.
Screenreader:Oh for crying out loud!  Can’t we skip that prt?
Browser: Fine.  Here’s your page already.
Screenreader: <hum while fill out form>
Browser: Hmm.  The website says that city and zip code don’t match.  Probably a typo, but I should tell the user.  I’ll set the polite ARIA property.
Screenreader: Interesting.  I see the polite property has a message.  I’ll wait for a good time to tell the user.  <hum more>.  Perfect.  User, while you are between fields, can you check this?  Oh, it’s wrong?  I see.  Good, we get to fix our mistake.
Browser: That was nice and polite of you.

Conclusion
You came to hear  a funny speech.  You learned what ARIA – accessible rich internet applications are all about.  Without even feeling like you were learning.  My motivation for doing this was the Head First series of books which often teaches through humor, dialog and personification.  Remember ARIA may be rude or polite, but always helpful.  Just like Head First.

[edited to add sock puppet picture]

SCJP Java Programmer Plus Certification delayed

What happened to the SCJP Java Programmer Plus Certification?
It got delayed.  As Campbell noted late this year is likely overly optimistic.

Announcement e-mail follows:


Update!
Sun Java Programmer Plus Certification Beta

Dear Jeanne,

Thank you for your interest in the Sun Java Programmer Plus Certification – Sun’s first performance based Java Certification exam.

We wanted to inform you that the full beta for the new Sun Java Programmer Plus Certification has been delayed to later in this year based on the results from initial beta testing and to align more closely with the upcoming release of JDK 7. We will get back in touch with you as soon as we have revised dates for the full beta test.

If you have any questions or feedback, please send a message to sunlearninglink@sun.com

Thank you,
Sun Microsystems