Rails Hash Ordering

My expectation was that when I create a hash it’s going to act like a queue and be sorted in the order in which I inserted things. As I found out today, that is definitely not the case.

There is a very easy way that Rails offers to give a hash this behavior and it’s the OrderedHash function found in the ActiveSupport libraries.

my_hash = ActiveSupport::OrderedHash.new

After that initialization, your hash will be maintained in the order you insert things. Something to watch out for.

A couple of Ruby on Rails v1.2 gotchas

I recently upgraded a few projects to Rails v.1.2 and had a couple of issues arise.

Disappearing objects when dropped using drag and drop in Safari

For one project I use the drag and drop re-ordering provided by the Scriptaculous library. Not sure what did it, possibly even a Safari update, but only in Safari, once you let go of a dragged object, that object would disappear. It would come back when you refreshed the page and would have successfully triggered its intended action.

I did update my javascript files upon upgrading to v.1.2.1, but had not upon the upgrade to v1.2.2 since I wasn’t aware of any changes. I think the release of Scriptaculous on its actual site is newer (v1.7 right now) than that included in Rails so I updated my scripts and that solved the problem.

Model attributes not in the database were inaccessible

I wasn’t able to figure this one out, but was able to get around it. I have a model which has some methods to send/receive messages to a device. I had a

attr_accessor :last_response

which is an attribute that’s not in the database. It was simple a place to temporarily store the full message of the last response for use later on in the code. After the upgrade to v1.2.1 things were fine. However after updating to v.1.2.2, I started getting “Method not defined” errors. It seems like other people have hit this one, too.

My solution was simply to remove the property and change it to @last_response which worked for my limited use of it.

I’m still scratching my head though, since similar attributes work fine in other classes. The problem class, however, is unique in that instead of having ActiveRecord:Base as its parent, the actual parent is a generic class whose parent is ActiveRecord:Base.

Keep up with your Rails tests

I haven’t updated my progress on the project I’ve been working on in a while. This is somewhat due to simply getting caught up in the development of it. I’ve also been working the past few weeks on creating the CSS/HTML based on the delivered design. Here’s two things I’ve learned about my experience since last time…

Don’t forget about running your tests

While I think I did a good job creating unit tests, I definitely let my functional tests slide. I have also not been religiously running my existing tests, so it wasn’t much of a surprise that a number of them were failing when I ran them again recently. As I fix them up, I’ll be keeping track of where they would have helped me out.

One thing I do know is where I need to have functional tests. I’m not nearly as concerned with pages which do nothing but display information, mostly ones where it would change, or redirect you based on security.

IE7 is much easier to style than IE6, but still not quite as good

Okay, This isn’t really Ruby on Rails specific. This assumes you create styles like I do. Create your CSS to work in Firefox and Safari and then get it to work in IE. I did run into some IE7 weirdness, but overall, there will be far less tweaks with it than you’d have with IE6. I created separate stylesheets with IE6 and IE7 fixes and the IE7 one is roughly 80% smaller than the one for IE6.

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