Skip to main content

RhoMobile - Ruby Development for Mobile

RhoMobile (http://rhomobile.com/) offers an open source framework which allows Ruby developers to write mobile apps using web technologies.

I have been using it for about a year now. You can find out the details of it on the website linked above, but I just wanted to go over some of the issues I have found and cover some of the pluses in minuses from a personal perspective to help you decide whether or not this is a technology you will want to exploit on your next project.

So what is it?

At a basic level, a Rhodes (http://rhomobile.com/products/rhodes/) app comprises of a small Ruby web server/framework and an embedded browser. Server is a little bit of a misnomer because it lives on the client, but essentially it's like a small Rails server which is only used by one client (though in theory you can connect to it from another client if you so choose).

Because the display is done in an embedded browser, you can mark it up in HTML and CSS and even (in some cases) use JavaScript to manipulate the display dynamically.

So why use Rhodes instead of creating a mobile web app?

Well, for one, you can package a Rhodes app and sell it in the app store, android market or app world.

It also (if you need it to) can sync with a sophisticated sync server known as RhoSync (http://rhomobile.com/products/rhosync/). As of the time of writing, RhoSync is built upon Sinatra and Redis (it used to be Rails and MySQL). This means that a user can manage and manipulate his/her data on their phone without the need for a constant internet connection and that data can be periodically synced with the back end. RhoSync manages all the potential data conflicts and only syncs the differences. It can connect to practically any kind of data store (databases, REST APIs, etc...).

So what are some of the limitations of Rhodes?

So, unfortunately, nothing in life is perfect. One limitation is that because it relies on embedded browsers, if your app does any fancy JavaScript or CSS3 you will have to write another set of HTML only views for BlackBerry (though apparently the latest BlackBerry versions use a WebKit browser. I have yet to try this personally though).

It also really is targeted at the high end smart phones. It is quite well optimised for iOS, but on slower Android devices (anything with less than a 600Mhz processor) it can be quite slow and sluggish.

Another thing to get one's head around is that even though the framework is Rails-like, it is not exactly the same as Rails (it is quite stripped down). The RhoMobile team have been busy adding features however so its ecosystem is growing. When I started using it, there were no models (only controllers and views). Since then, Model support has been added as well as MSpec for testing.

Once your product is done, adding it to the respective app markets is also quite a hassle. This is by no means the fault of RhoMobile or the Rhodes team, but it is something to consider when trying to decide between doing a web based app vs an installable one.

The other limitation is because Rhodes is designed to work with most of the major smart phones on the market, you haven't got access to all the available features on a specific mobile phone. There is limited camera and calendar support, but currently no audio or video recording (it's in the road map, but not yet available). So you are not going to be able to write an app like Shazam or Google Maps using the framework...

Conclusion
If you like Ruby, web technologies AND mobile apps then it's definitely worth taking a look at RhoMobile. It's especially suited for Enterprise App development where you may not need the latest fancy UI enhancements, but you do want to deploy on all the platforms that your team is using with a single code base.

More References

You can find more information on the app I developed at
http://rhologic.com/

Comments

Adam Blum said…
Hey Anthony,

Nice to see this post. Overall fair and balanced. What camera support do you think is missing? What about calendar support is missing?

- Adam
skuunk said…
Hi Adam,
You currently cannot choose the size of the photo taken by the camera. Also as each calendar item does not have a unique ID field, you cannot really sync all your CRM calendar items with your device (you can add individual calendar items, but it is up to the user to resolve any conflicts).
Anonymous said…
The rapid proliferation of smartphones and social media redefined the very meaning of "internet marketing." custom applications
ipad application development

Popular posts from this blog

Freezing Gems

What is a gem and why would you want to freeze it?

In Ruby, there are times when you want to access pieces of functionality that other people of written (3rd party libraries) and you normally have 2 options. You can install a plug in or install a gem. Normally the method you use is determined by which ever is made available by the author.

Gems are installed on the host machine and are pretty handy when you want to run things in the command line or else across lots of projects, but their downside is that if you use a gem in a Rails project there is no automatic publishing mechanism when you deploy your site. You will need to log onto the remote host machine and install the gem manually.

Plugins are specific to Rails and are similar to gems in that they are also 3rd party libraries. However they are associated with your Rails project as opposed to your machine so they will get posted to the server on a regular deploy.

Freezing a gem is the process of transforming a gem into a plug in. Essen…

Comparing Rails' Active Record Pattern with Phoenix/Elixir/Ecto

Rails has a very well established Active Record pattern for dealing with the database. You have an Active Record model which maps to the database table, the schema of the model comes directly from the database schema and you place your model specific methods on the Active Record model. This file is also where you set your model relationships (e.g. has_many, has_one, belongs_to). Your instance of the model has all the methods built in.

In Ecto/Phoenix it's a little different. First of all, the database schema doesn't automatically map to the "model". In fact we don't really have models (as Elixir is a functional paradigm). What happens in one file in Rails, happens in essentially two (or more). You have a schema file (where you have to list out all the attributes and relationships). Using the schema file, your "instance" is essentially a data structure (with no methods on it). If you want to transform the data on your struct, you would use a context modu…

Unit/Functional Testing RubyAMF

One of my current projects is using RubyAMF to communicate with Flash (http://rubyforge.org/projects/rubyamf/). On the whole this is really nice because it allows you to transfer Ruby objects directly to ActionScript ones (as opposed to translating the object into XML, sending the XML and then recreating the object in ActionScript).
However, Rails does not provide a built in transport mechanism for AMF, so we cannot run functional testing directly on the data call (as we could for an XML or HTML transport layer). This is a show stopper for a lot of people (Rails w/o Unit testing = a big mess of trouble when something goes wrong).
We can though serve both the HTML and the AMF formats depending on the request format. This means that we can test the object instantiation logic and make sure there are no errors in the controllers (though we cannot check the actual format of the data being served). In the controller, instead of rendering AMF alone, do the following respond_to do |format|