IE + Rails Javascript Caching Gotcha

Posted by: on Apr 30, 2010 in Blog | Tags: , | No Comments

Rails supports a simple method of asset bundling with javascript_include_tag by way of the :cache option:

<%= javascript_include_tag 'first', 'second', 'third', :cache => true %>

There’s a gotcha hiding here that you may not find until you deploy to production and visit your site in IE.

Admittedly, this is a bug, but if you happen to have a second javascript_include_tag with the :cache argument in the same page, IE will choke on lots of the script, telling you “object doesn’t support this property or method,” among other things.

The problem is that Rails can’t resolve multiple tags using the same value for :cache, and it emits two <script> tags referencing the same Javascript file. IE gets confused by the second one (perhaps loading it twice?). Every other browser I’ve used handles it fine.

The solution: either don’t use :cache more than once or make sure you use explicit, unique bundle names instead of just true.

Xcode User Defaults

Posted by: on Apr 29, 2010 in Blog | Tags: , | No Comments

Xcode as a development environment matches my working style fairly well, but there are two things about it that have bothered me. The first is a warning when I try to undo edits across a file save event. Since I have Xcode set up to save all files before a build, this happens often when I try an experiment and don’t like it.

The second is code completion for language constructs such as if statements. Xcode wants to do this:

if (condition) {
}

While I used this style a long time ago, today I want the opening brace on its own line:

if (condition)
{
}

No amount of digging in the preferences will provide a way to change these behaviors, however there is a lot of customizability hidden in the Xcode User Defaults. My two issues are solved quite easily:

$ defaults write com.apple.Xcode XCShowUndoPastSaveWarning NO
$ defaults write com.apple.Xcode XCCodeSenseFormattingOptions -dict BlockSeparator "\n"