Extending an existing Rails application that wasn’t meant to be extended

I am modifying an existing open source rails 4.2 app and wanted to keep my changes (some of which are to models, some to controllers, some to views) as separate as I can, so that when a new release of the app comes out, I won’t be in (too much) merge hell.

This app was not designed to be extended, which makes things more interesting.

For the views, I’m just doing partials with a prefix (_xxx_user_cta.haml).

For the models and controllers, I started out hacking the code directly, but after some digging around I discovered how to monkey patch (I believe that is what it is called) the classes.

In the config/application.rb file, I added the following code:

config.to_prepare do
Dir.glob(Rails.root + "app/decorators/**/*_decorator*.rb").each do |c|
require_dependency(c)
end
end

And then, if I want to make a change to app/models/person.rb, I add the file app/decorators/models/person_decorator.rb. In that file is something like this:

Person.class_eval do
# ... changes
end

This lets me add additional relations, helper methods, and other classes to extend existing functionality. I try to prefix things with a unique identifier (xxx_set_timezone rather than set_timezone) to lessen the chances of a collision, because if a method is added to the Person class with the same name as a method in the decorator, the decorator will win.

Write tests around this new functionality so that if anything changes, I’m aware and can more easily troubleshoot.

The downsides of this approach is that it is harder to track logic, because instead of everything in one file, it is now in two. (I don’t know if there are memory or performance implications.) However, that is a tradeoff I’m willing to make to make it easier to keep up with the upstream development and to pull said development in as often as possible.

I’m still fairly new to rails and didn’t know if this is the only or best way, but thought I’d share.


Early Product Lessons

fence-238475_640I wanted to jot down some lessons I’ve learned being an early stage technical founder of an unfunded startup, from no product or revenue -> product and revenue. (Of The Food Corridor, if you’re interested in the startup.) I had the luxury of a co-founder who had spent years immersed in the problem space and months researching the niche. If you can find that, it really really helps in product development.

That said, here are some other lessons. For an idea of our timeline, we did a build or buy or both evaluation in March, started building in April, did beta testing in May and launched June 1.

 

Determine features through demand/pull, rather than push

Once you have a product that you can show users, show it to them!

It will be embarrassing.  Record all their feedback and note patterns (we did a month of beta testing, as noted above). Then, let the user requests pull features from you, rather than push features to them. This serves a couple of purposes:

  • people will know that you are hearing them, and will be more forgiving of inevitable issues
  • you will build features that people want to use
  • you’ll develop a sense of users needs
  • you’ll learn to politely say no to requests that are off base/only useful to one user

Everything is broken

Everything is borked, all the time. At an early stage startup you just don’t have time to do everything right (nor should you, because the wrong thing perfectly engineered is a waste). So there will be features that are half done, or edge cases unhandled, or undocumented build systems. Do the best you can, and realize that it gets better, but make your priority getting something out that users can give feedback from. “Usage is like oxygen for ideas.” – Matt Mullenweg

You have to walk a fine line between building something quickly and building something that you can build on later.  Get used to ambiguity and brokenness and apologizing to the customer.  (But not too used to the apologies!)

UX/UI polish is relative

Our app is a number of open source gems smashed together with some scaffolded ruby code.  The underlying framework had a decent look and feel, but there are definitely some UI and UX holes.  I thought I’d have to spend some time working on those, but our customers thought the product was beautiful and useful.  My standards were different than their standards.

That doesn’t mean that the app can look horrible, but a plain old bootstrap theme or one of the other common CSS themes is ok. You need to know your audience–many people are stuck using a mix of software and are used to navigating clunky user interfaces. If your interface is just decent, but still solves the problem, you’ll be OK.  Of course, you’ll want to solve gross UX issues eventually, but a startup is all about balance.  A friend of mine gave me the advice: “don’t allow your users to make any mistakes”.

Favor manual process for complex edge cases

There have been a couple of situations during the build where a lot of work was needed to handle an edge case. For example, prorating monthly plans. Once you start thinking about prorating in depth, it turns out to be a really interesting problem with a lot of edge cases. But guess what?  For your startup, edge cases can be a wild goose chase.

When an edge case rears its head, you should consider the following options (in preferential order).

  • can you outsource the complexity (Stripe handles proration, for example, and I guarantee you they handle edge cases you don’t).
  • can you make it a manual process? If it doesn’t happen that often and/or a real time response is unneeded, you can often get by with a manual solution. This may be partly automated, for example, an SQL query that generates an email to a human who can handle the exceptional situation.
  • if neither of the above apply, can you defer it? Maybe for a few months, maybe for just a few weeks. But sometimes requirements change and you learn things from users that may make this edge case less important.
  • if all of the above don’t apply, you may need to bite the bullet and write code.

Back end and front end development doesn’t have to be synchronized

Most users equate the front end with the complete product. Most developers know that, just like an iceberg, there’s a lot of back end processing hidden in any project. But guess what? When you are getting feedback from users, some of the backend processes need to work, but many don’t. For example, we had a billing system that handled monthly invoices. We didn’t need to build the billing system while we were getting feedback from users on what type of charges they needed to handle. We did, however, need to know that we could build it. So make sure you can build the backend system to support your front end system, perhaps by building one path through, but defer the full build-out until you have to.

What about you?  Any tips for early stage product engineering?



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