Monday, August 17, 2009

Agile, TDD and upfront desing

As TDD and agile software development are emerging as more and more used technologies for software development lot of software developers are jumping into it without having real knowledge.

From my point of view one of the misconceptions about TDD and agile is that you don't need any design and architecture upfront. TDD with refactoring will give me the right architecture in all cases.

Although I am big fun of agile software development I don't believe this is idea of the agile. Agile is here to help develop better software for better customer satisfaction. But it in no cases claims that you should forget about big picture, about documentation and about having at least basic understanding of your system design.

From my point of view you need to do basic design at least at the high level. Then for important parts you need to go to lower levels (if really necessary). And then agile together with TDD will help you to really get it right. To separate concerns, to make separation between domain objects in different tiers and so on.

So as conclusion, agile does not mean no more thinking. Agile means think about the problem, do basic planning and then use TDD and other agile tools to get it right.

Monday, August 10, 2009

g:form, g:actionSubmit and Internet Explorer 8

While working on my latest grails powered web site things to do with kids I have noticed that one form performs ok in Firefox and Chrome but not in Internet Explorer. If this would be case with grails tutorials I wouldn't care too much because majority of visitors have Firefox or Chrome. But my statistics for things to do with kids are showing that there is more visitors using IE than other browsers.

The problem was following. E.g. on the home page of things to do with kids you enter the city name and then press enter on your keyboard. In Firefox and Chrome you get the list of places to visit but in IE8 nothing happened.

But if you used tab to move focus on the Show Me button then everything worked also in IE.

The initial code looked like this:

<g:form controller="home" method="GET">
<input name="locationName" class="span-10 last" />
<g:actionSubmit value="Show me" action="placesAroundLocation" />

After some investigation I noticed that closure called from IE was actually index in the HomeController. So this means that in IE8 when enter is pressed while focus is in the input box default action of the controller is called while in Firefox and Chrome action of the button was called.

So to fix the problem with the IE I have slightly change the code. I added form default action so now it looks like this:

<g:form controller="home" action="placesAroundLocation" method="GET">
<input name="locationName" class="span-10 last" />
<g:actionSubmit value="Show me" action="placesAroundLocation" />

I didn't check behavior in other versions of IE but if you have similar problem this may help you.