May 2008 Archives

RailsConf 2008 is almost upon us. This will be an ideal opportunity for members of the Spree community to meet face to face and discuss all things Rails commerce. We have no official sessions planned and I have decided against organizing an official BOF this year. I’ve been really busy lately with client work and trying to get Spree ready for its first official beta. I’d rather use the remaining time that we have to make progress on that front instead of organizing a formal BOF.

One of the things about conferences that I enjoy most is meeting fellow developers. So if you want to get together for coffee, breakfast, lunch, dinner, beers, etc. let me know. If there is sufficient interest we could also schedule an official Spree happy hour and meet up at a local watering hole. Just drop me an email or ping me on IRC if you would like to meet up.

Just a quick writeup for those of you you who have a Spree fork and you want to grab the latest changes (since the point of your fork.) Run the following git commands from inside your local fork.

git remote add spree-github git://github.com/schof/spree.git
git checkout -b spree-official/master
git pull spree-github master
git checkout master
git merge spree-official/master

This creates a branch before merging. That’s the absolute safest way to do it. If there are conflicts and you don’t want to deal with them you can just switch back to your main branch and delete the spree-official/master branch.

The shortcut way to do this (with no special branch) is as follows

git remote add spree-github git://github.com/schof/spree.git
git pull spree-github master

You can find this and other git cheats in the brand new Git Cheat Sheet.

I have just checked in a major improvement to the payment_gateway extension (part of the core Spree functionality.) You can now use /admin/gateways to configure your payment gateway (the old method involved editing environment.rb). So far the only gateways supported are the Bogus Gateway and LinkPoint. Not a lot of choices but that is easily fixed. We just need to test each of the ActiveMerchant gateways with Spree and then add them to the extension.

In development mode, you will always use the BogusGateway no matter what gateway you have chosen. In test mode you will get your chosen gateway but it will be set to test mode. ActiveMerchant handles what exactly test mode implies for each gateway, but it usually involves a special test URL for your gateway and possibly passing other parameters to indicate a test. Production mode will use the live gateway in the manner your would expect.

Besides adding a useful feature, this was also a nice test of the extension mechanism. This also makes a good example to look at for those of you contemplating making your own extensions. The only real problem I have noticed is that the routes introduced by an extension do not automatically reload in development mode. So that stuff required restarting the server every time I wanted to change the route. Rails has spoiled me to the point that a single reload of my server annoys me. I’ll track this down and fix it shortly.

Today on the #spree channel two different people asked how to run locally from the source. I took that as a sign that we could use some documentation in this area. As a result, I have written up some basic instructions on doing just that. There have been some other additions and improvements to the documentation including a noteworthy write up on extensions.

We’ll be doing our best to provide more documentation over the coming days. Keep in mind that the documentation is all in the wiki. That means that any of you can help us with the editing or with new entries. Perhaps you might want to write up your own tutorial?

Now that the basic extension mechanism is in place I am experimenting with the concept of so-called “core extensions.” These are extensions that will ship with the gem and provide core functionality. They reside in #{SPREE_ROOT}/vendor/extensions. NOTE: This is not the same as #{RAILS_ROOT}/vendor/extensions. So far we have a PaymentGateway and TaxCalculator extension. The idea behind core extensions is to make it easier for developers to customize Spree to fit their own needs. Taxes in particular are likely to differ depending on your client and/or location. It will soon be a simple matter of turning off the default extension and dropping in your own replacement.

The payment gateway extension is not very interesting at the moment. Right now it always returns the BogusGateway, but in another day or two it will be possible to configure the ÅctiveMerchant gateway of your choice through a nice admin interface. No more configuring the gateways in environment.rb! The other cool thing it does is to mixin a payment_gateway method into Spree::BaseController. This is the method that returns the gateway to be used for processing credit cards. If for some reason you don’t want to use ActiveMerchant to talk to your gateway you could plug in something else here.

While it’s unlikely you will need to scrap ActiveMerchant (since you can always write your own ActiveMerchant implementation for your new gateway), you will probably have a definite need to customize your tax logic. The current TaxCalculator extension will allow you to set tax rates for individual states. If the order ships to that state then all items will be taxed at that rate. There is no admin menu item for this yet, but you can see the rate interface at admin/tax_rates if you are running the latest source (demo has yet to be upgraded.)

Although this is fairly crude, it’s also pretty much what you’re stuck with in many of the existing commerce platforms. Even though we will be adding to this basic calculator over time, we fully expect that your needs will go beyond this. This is where you unfortunately have to earn your money as a programmer and do a little programming. Its a fairly easy process to create your own extension. Documentation on extensions is ongoing but there is an in-progress tutorial in the Developer’s Guide. Stay tuned for more information on making your own extensions. We are also working on some interesting taxonomy features that should make it possible to mark only certain items as being taxable.

The latest source code now includes basic support for extensions. For those who don’t already know, extensions provide the means for developers to provide new (or override existing) models, views and controllers. They are a standard way of extending basic Spree functionality and are intended to allow individual developers a mechanism for customizing Spree while minimizing the likelihood of problems when upgrading to a subsequent release.

In the near future, Spree will also include several built in extensions. One such extension will provide for basic tax calculation. The idea is that Spree users will write and share their own extensions within the community. Such cooperation is now easier then even with the advent of git and github.

A word of warning on the current state of extensions. The code is very rough. It has been subjected to only minimum testing. We will be working out most of the issues the next few weeks as we prepare for the first beta release. Now that we have multiple contributors actively working on the project I wanted to make sure the code was made available ASAP. So consider extensions a work in progress at the moment. For those who are curious to see what they look like, they’re now available for your consideration. Stay tuned to the slowly expanding documentation featured in the developer’s guide for more information.