tekin.co.uk - Ruby on Rails developer, Tekin Suleyman, Manchester UK

New in Rails 2.3 - Disabled option tags and lambdas for selecting and disabling options from collections

2009-03-06T00:00:00+00:00

As it seems to have slipped through the usual channels, I thought I’d document a couple of enhancements to the form option helpers here.

Disabled option tags

The form option helpers have been updated so that you can now specify disabled option tags:

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Disabled option tags appear greyed out and cannot be selected by the user (or at least they do in normal browsers – see below).

Lambdas for selecting and disabling option tags from collections

You can now use anonymous functions to specify which members of a collection should be selected or disabled in the resultant option tags. For example, you may want to disable product sizes that are out of stock:

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This works exactly the same for selecting values, simply pass your anonymous function in as :selected.

A word of caution – always coding defensively

Although disabled option tags are part of the HTML specification, Internet Explorer 6 and 7 do not support them and will display disabled option tags as selectable. And although there are hacks to get IE to behave, you can never guarantee that disabled values will not be submitted by someone constructing a html post. Therefor, it’s always best to code defensively and guard against the potential selection of disabled values in your controller actions.

Disabled option tags in rails forms

2009-01-05T00:00:00+00:00

Update: My patch has now been accepted into core, which means that as of Rails 2.3, this plugin should no longer be necessary. More details here.

Ever wanted to disable options in a form select in rails? I have; it feels more useable to me to disable out of stock product sizes:

The rails Form Option Helpers won’t let you do this as they currently stand. So until things change in core, I’ve put together the option_tags_will_disable plugin.

Simply specify the disabled values when calling options_for_select:

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You can do the same when working with collections, but more interestingly, you can also give a Proc to identify which elements should be disabled:

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And as an added bonus, selected options can also be identified with a Proc!

Rails gets some engines love

2008-11-26T00:00:00+00:00

No sooner is Rails 2.2 out the door than edge Rails gets exciting again!

A tasty little commit hints at some major changes to the way Rails handles plugins. Finally, the awesome features of the engines plugin (lovingly crafted by James Adams) will be creeping into core.

I’m not one to speculate what brought about the change in heart, I’m just glad Rails is finally drinking the engines Kool-Aid!

Engines? Wha?

As it says in the README: “The engines plugin enhances Rails’ own plugin framework, making it simple to share controllers, helpers, models, public, assets, routes and migrations in plugins”.

In a nutshell, you get to create slices of apps as plugins which makes it a piece of cake to to share common functionality between multiple applications. In my case, I’ve been able to put together several e-commerce websites with practically all the core functionality provided by a set of plugins. The beauty of it is, you can easily override views, actions, etc, in your app to make each site it’s own. And when you fix a bug, or add a new feature, all the sites can benefit!

What comes next?

It’s still early days and it’s not yet clear just how much of this is getting rolled into Rails, but James has hinted that much will make it across, including migrations, routes and asset management.

In the mean time, if you want to see what all the fuss is about, check out the engines plugin which, thanks to the hard work of everyone involved, now runs happily on Rails 2.2!

Update

The commits are coming thick and fast now. I’m certainly looking forward to road testing these new feature as they take shape.

Rails and git submodules can play nice

2008-08-11T00:00:00+01:00

I use git submodules to track plugins that I have under active development. This way, I can make changes to the main repository as well as the plugins with minimum fuss. There’s a great tutorial on working with submodules, which includes a couple of gotchas that may explain why submodules have got such a bad rep from some quarters.

Gotcha No. 1 – Always commit changes in your submodules before commiting your main repository

If you make any changes to a submodule, be sure to commit and publish these changes before you commit anything in the main repository, otherwise you and others will have issues trying to clone the repository.

Gotcha No 2 – Check you’re on a branch before making changes

If you are cloning a repo with a submodule and run git submodule init/update, be aware that the submodule has been checked out at a specific commit as apposed to the head of a branch meaning you have to checkout a branch before you make any changes.

Passenger/mod_rails 2.0 RC1

2008-06-12T00:00:00+01:00

The guys at Phusion have been hard at work improving mod_rails and a release candidate for 2.0 is now available. This includes: rack support; faster graceful restarts; less memory usage; fair load balancing; upload buffering; better stability and much more. Upgrade now for an instant win!

Update: if you have problems installing from the gem, get the latest version from github.

mod_rails and apache on OS X Leopard

2008-06-02T00:00:00+01:00

I was going to write up my experience rolling mod_rails on the default install of Apache to tidy up my development environment, but someone beat me to it!

There’s only one thing I did differently – I like to keep my apps in the Sites folder to keep things tidy – so in the spirit of keeping things DRY I won’t duplicate an already good write-up, but I will add a couple of points that caught me out.

Apache 2 and NameVirtualHost

If you find that Apache will only serve up the first of your virtual hosts, check you’ve correctly specified the NameVirtualHost directive.

Beware, FileVault and permissions

If you’re running FileVault, you might have a bit of fiddling to do with your file permissions.

Rails plugins and the move to gems

2008-05-31T00:00:00+01:00

This week, I made my first contribution to core which made installing plugins from git repositories over ssh work. It was a pretty small, mangy little patch – nothing more than fixing a typo in the end – but it felt good giving something back to a framework that has given me so much.

Now that I’m newly freelance, I’m hoping to be able to spend more time giving back to the Rails ecosystem, and the first port of call might have to be the plugin management system. I know plugins are becoming decidedly unfashionable with a lot of smart people saying they you should be using gems instead. And with the recent additions to rails this makes even more sense and you really should be removing those plugins from your apps in favour of loading them as gem dependencies. But in some scenarios, a plugin is all that will do.

In my case, I make use of the engines plugin (another unfashionable and often misunderstood bit of rails goodness) to share common application structure between a few apps, and here the whole plugin-as-gem thing just doesn’t fit.

Having been underwhelmed with the Piston equivalents for git, I’ve found myself using ./script/plugin install again, and although this now works with git repositories, ./script/plugin update doesn’t. Can it be that hard? Time to find out…

My blog is born

2008-05-27T00:00:00+01:00

Finally after much twiddling with WordPress themes (so glad I don’t work with php anymore) here is my new blog! Because every freelance Rails developer worth his salt needs a blog, right!?

Thanks to Sophie for the great design. Now all I need is some actual content…