Spree as a mountable engine - ruby-on-rails

So, we want to rearchitect a portion of our site as a Rails app. The original plan was to have a main "site" app, with a number of plugin apps (Rails 3.1 Engines) with compartmentalized functionality -- a store component, a social/forums/chat component, etc. Also, we wanted to put themes/styling in a gem so that our web designers could modify the site appearance and some minor layout tweaks without having to "know Rails." Initially, this was going well; we created the main architecture and plugins and the theme gem, and it was all playing nicely together; cross-cutting functionality like auth was put in the main "site" app and was consumable by the plugin apps, giving us a single sign-in for the site (a design requirement).
Our initial plan for the store component was to use the Spree (http://spreecommerce.com/) since it had, out of the box, 95% plus of the functionality we needed. However, there's a catch -- Spree is distributed as a mountable engine, but it's also an app. Meaning that not only does Spree mount inside an app (which is not a problem, in fact it's behavior we were counting on), but it depends upon being in control of the main app. Looking into the "why" for this behavior, it seems to depend upon two core pieces of functionality. The first chunk of functionality is some SEO permalink rewrite functionality that has to go into middleware; we could hack things so that our main app included this chunk of code (even though this would begin to entangle store functionality across our entire site, muddying the "Spree as a mountable engine" story... more on that in a moment).
More complicated is Spree's use of Deface to do theming and customization. While this is "clever" (note quotes), it really makes the integration of Spree kind of a nightmare; either you follow the path of least resistance and make Spree an entire store to itself (which completely breaks our story of "the store is just one part of our site, and plays nice with the rest of the site, including auth, theming, etc."), or you have to hack the hell out of Spree.
Not only that, but Spree doesn't follow the standard Rails Engine routing paradigm, where routes are isolated beneath an engine root (if you look in the lib's routes.rb file, you can see that it uses Rails.Application's routes, instead of an Engine's routes). This means that we couldn't have www.oursite.com/store/...all_the_spree_goodness, we'd have to have www.oursite.com/spree_owns_the_sites_routes...
So, has anyone else tried this? We LOVE Spree and would like to use it as our store. But it's starting to look that there's no real way to "integrate" it with the rest of our site aside from maybe some proxying magic with nginx or something like that (which is a separate nightmare, since we're hoping to host on Heroku, and then we have to figure out how to integrate multiple disparate apps into one DB -- for single sign-in auth -- and an HTTP front router).
Spree devs, we LOVE your code, but is there any work being done to make it an actual, for-real Rails Engine, as opposed to a stand-alone app that just happens to package all of its features into Engines? Without the ability to integrate it into an existing site (including not "owning" the app, being able to have all of its routes partitioned off, and so on), there's just no way we can use it :(
TIA.

I'm the Community Manager for Spree, so I think I may be able to answer your question.
Yes, there is work going on that will allow Spree to be a true Rails engine. In fact, that was my first task that I did when I was hired by Spree. The work is on the master branch (https://github.com/spree/spree) and we're looking to release this code as a 1.0.0.rc around Christmas time.
With this code, a couple of changes have been made. For starters, Spree is now a proper Rails engine meaning that you can now have it mounted at /spree or /shop or /whatever and Spree's cool with that. Secondly, all the models and other classes are namespaced so they won't conflict with anything in your application.
I'm not sure what you mean about Deface being "clever", though. What problems do you forsee with this? If you want to override an entire view you could do this by overriding the path in app/views/spree/products/show.html.erb. Mind you, this overrides the whole view, and if you only want to override a part of it that's when you'd use Deface.
Could you perhaps elaborate on the issues you're having with Deface? Would be interested to help you sort them out.
Thanks for using Spree!

Related

Share code/configurations/conventions/gems between Rails apps

THE PROBLEM
First a little bit of context: I am currently working as a freelancer, developping webapps using Ruby on Rails. Because I am working solo, the need to optimize my workflow is pretty important.
That's why I have always had the same question since I begun working with Rails:
How can I share code/configuration/conventions/tests between my apps?
More precisely, I want to share:
common gems that I always use, with their configuration
common integration tests, to ensure some conventions
common view helpers, test helpers, extensions to the core classes, javascript/sass partials
common files: .gitignore, git hooks, .eslintrc, configuration files of my CI etc
Some concrete examples of what I need in all my apps:
disable turbolinks by default, to add it later if need be
use javascript instead of coffeescript
use slim instead of ERB
install/configure capistrano
install a CSS framework (bootstrap, bourbon + neat + refills)
So far I don't really have the need to share models nor controllers.
I don't want to share behavior or functional components of the system itself, I am not looking for a micro-services architecture.
I have found that so far when creating new applications, all this setup work does take me a lot of time. Also, I would like to apply it retro-actively to existing apps when I add something new.
I have done quite a bit of research, but I haven't found a lot of answers. Many people are trying to share models, but few people seem to want to share a common ground between all their apps. Finding the right keywords may have been the problem though.
It seems to me that Rails is really good at DRY within an application, not so easy when trying to DRY between applications.
POSSIBLE SOLUTIONS
1 - Rails application template
The solution I am using right now, described in the Rails Application Templates guide, using the same API than the Rails generators described in the Creating and Customizing Rails Generators & Templates guide.
That's the solution used by Thoughtbot, with their popular suspenders gem. In the case of Thoughbot though, they have years of experience to draw from, have many employees and their common setup does not change that much.
Pros:
saves a lot of time when creating a new application
really nice API
Cons:
a lot of duplication: all the apps have the same common code, with the problem of this code getting out-of-sync
not retroactive: useless to add a common feature to already created apps
heavy maintenance work: my current workflow is to go through the git log of my apps once per month, and for each commit that could be common to all the apps I have, add it to the application template, and add it to the other apps manually
So far this solution is not that bad, because I only have two applications. But once I will have more, I will suffer from more and more overhead.
A better solution would be maybe to create a generator/rake task for every common new feature, to be able to apply it quickly to existing apps, and call it directly in the application template for new apps.
I haven't tried it though, and I am not really sure it will work. For example what if I want to propagate a one-line change in an existing common file in all the apps?
2 - Rails Engine
I have tinkered a bit with the Rails Engines to share code.
I have not understood from the Getting Started with Engines guide if I should better use a --full engine or a --mountable one for this specific purpose.
Pros:
once I update the gem version, all the changes are made available to the app
DRY: all the common code is in a unique place (the gem)
Cons:
the gems I would like to share are put in the *.gemspec file, which has not as many features as the Gemfile (from what I understand)
overhead caused by the need to update the version of the gem in all the apps, migrate to the new API of helpers, etc
no way to share non-rails files (.gitignore, git hooks, .eslintrc)
This solution has too many important shortcomings.
3 - Hybrid solution: Rails Application Template + Rails Engine
Maybe the best would actually to use both the above solutions.
In the gem share helpers and tests, in the rails template share the gems, their configuration/files and other files (for git, linters, etc)
It is indeed adding more complexity and overhead...
4 - Use git subtrees
Some people use git subtrees to share folders between multiple webapps.
Cons:
one has to share whole folders, not easy to share everything I would need, in their different target directories in the rails app
seems a bit "hacky" to me
Conclusion
Is there another solution than the ones I mentionned above?
What do you think would be the best way to do it?
How about having a blank "Master" rails app in the git somewhere. With all the settings and configurations you'd like to share. When creating a new app from scratch, you can merge the "Master" into it to apply the defaults. When you have an existing app, same thing, just merge and resolve conflicts as needed.This also gives you the ability to override the merged code if needed to.
Few things I can see wrong with this approach though:
Rails application name could cause a lot of headaches
Any updates could cause merge conflicts
I created a tool to deal with this when working in nodejs projects. But the tool is really just a command line tool so you should be able to use it.
https://github.com/tomasbjerre/dictator-builder
It is a concept with creating a dictator that dictates parts of your code base.

Rails application architecture and common setup

So I am starting out on company project that will have several components:
At first...
Job list
Client profile creation and management
User administration and access (login, signup, roles, etc)
later...
Messaging
Schedule
Basic reporting
way later...
Deeper analysis and bi
I'm wondering if it makes sense for each bullet item to be its own rails project, self contained and modular (if that is indeed the case); or if it's just best for it to be in the same app. I could envision a situation where each module could operate so independently of each other that it wouldn't need the rest (except for the user funcionality) and another situation where all modules would be used together.
It seems like to me that many tasks can be handled with a lighter framework like Sinatra (and then situated physically under the rails app). It also seems like it would be a lot of overhead to have several rails apps running on a server. But I am not totally aware of all the pluses and minuses to operating each scenario.
I know this is kind of a general question that is bound to get a lot of "it depends" kind of responses (and rightfully so) I was looking for opinions/examples of how you setup this kind/your kind of project in rails. I am a quasi noob so be gentle.
Thanks in advance!
Generally speaking I would consider a website to be a suitable target for a Rails app. Each part of the app can have its own namespaces within the app, so the app has some structure internally, but they should all be one application. Consider things like sessions, where you want a user to login and use whatever features of the site you want. You want those sessions in one application without a user having to login to different sections.
Saying that, if there is complex or extended functionality that isn't part of the MVC architecture (say talking to an external API, data-mining etc), then you could offset that to a separate project and a include it as a Gem in your application. You would still have one main Rails application that includes those Gems.
You might also want to bundle together a section of your project into a reusable Rails engine that can be loaded into multiple projects. For example, Devise handles user login and management. It is a Rails engine, bundled as a Gem, that you include in your project.
Another example from Meducation (one of my sites). I'm in the process of extracting our email tracking system out into its own Rails engine as I feel its functionality sits alongside Meducation and is not a core part of it. I can then use it in other projects as well.
In your specific example, I think your requirements fit fine in one Rails application.

How to decompose a Rails app into different small apps ecosystem

My team has been developing a bunch of modules in a monolithic Rails app for internal use. The modules are for example leave request, staff info, tasks/todo etc. Each module has its own purpose but somehow is linked to common information such as staff profile and user authentication. Each module has a developer assigned and they commit code to the same Rails app. Currently, it's super hard to maintain the code and scale. Now, I'm doing my research to decompose the app into small distributed apps and make them an ecosystem. Here are the concept I'm looking for:
There should be a master app that maintain the views of other client apps. Better yet, it acts as a platform for other client apps to plug in to it. Staff logs in to this master app to access client app.
Master app should render views of client app using AJAX or other ways (not decided).
Although, I want to decompose the apps, but each app should still be able to query resources/data such as staff profile from other client app in the ecosystem.
Actually, I have not decided about the interaction of each app. Thinking to us RESTful (not decided).
It should support development environment where each developer can develop each app independently. Hence, maintaining their own code in their own git repository. This is probably the main purpose of decomposing the app in the first place.
I'm reading Service-Oriented Design with Ruby on Rails book, but it seems like they focus on decomposing an app into small different services, whereas I want to have small different apps. Just wondering if there's any other ways to do.
Sorry for a long question and asking too much. Just want to know if you have been in the same situation and can guide me to some articles, communities, books so that I can continue more on my research.
Ah the joys of refactoring. It can be a tricky dance trying to structure an application into logical groups so that parts can be decoupled.
I would strongly suggest looking into Engines, with the Engines vs Mountable being very informative. This allows you to build a mini Rails app (aka an Engine) that can be packaged as gem. The custom Engine gems are bundled into a Rails app, providing a complete set of configurable functionality (models, controllers, views, etc).
The usefulness of Service-Oriented Architecture depends a lot on what kind of data you are pushing and pulling around. That being said, Rails is really wired for RESTful, so you get a lot of bang for the buck with that route.

Multi domain rails app. How to intelligently use MVC?

Background:
We have app a, b, and plan to add more apps into this same application. The apps are similar enough they could share many views, assets, and actions. Currently a,b live in a single rails app(2.3.10). c will be similar enough that it could also be in this rails app.
The problem:
As we continue to add more apps to this one app, there's going to be too much case logic that the app will soon become a nightmare to maintain. There will also be potential namespace issues. However, the apps are very similar in function and layout, it also makes sense to keep them in one app so that it's one app to maintain(since roughly 50% of site look/functionality will be shared).
What we are trying to do is keep this as clean as possible so it's easy for multiple teams to work on and easy to maintain.
Some things we've thought about/are trying:
Engines. Make each app an engine. This would let us base routes on the domain. It also allows us to pull out controllers, models and views for the specific app. This solution does not seem ideal as we won't be reusing the apps any time soon. And explicitly stating the host in the routes doesn't seem right.
Skinning/themes. The auth logic would be different between the apps. Each user model would be different. So it's not just a skinning problem.
In app/view add folder sitea for sitea views, siteb for siteb views and so on. Do the same for controllers and models. This is still pretty messy and since it didn't follow naming conventions, it did not work with rails so nicely and made much of the code messier.
Making another rails app. We just didn't want to maintain the same controller or view in 2 apps if they are identical.
What we want to do is make the app intelligently use a controller based on the host. So there would be a sessions controller for each app, and perhaps some parent session controller for shared logic(not needed now). In each of these session controllers, it handles authentication for that specific app. So if the domain is a.mysite.com, it would use session controller for app a and know to use app a's views,models,controllers. And if the domain is b.mysite, it would use the session controller for b. And there would be a user model for a and user model for b, which also would be determined by the domain.
Does anyone have any suggestions or experience with this situation? And ideally using rails 2.3.x as updating to rails 3 isn't an option right now.
Devise does exactly this. You would do well to check out its architecture and apply that architecture to your own case.
You will have multiple separate Rails applications. The shared code will be a separate project, perhaps distributed as a gem or at least a separate Git repository. The shared code will include many controller actions and many view templates that are there to be sensible defaults, and which will be overridden in some apps but not in others.
All the custom code for application A will belong in a project solely devoted to containing the custom code for application A. It will be its own fully-functioning Rails application and will depend heavily on the majority of the sensible defaults provided by the shared code in the shared-code project.
I've used the theme support plugin before and dynamically set the theme based on the request uri:
http://mattmccray.com/svn/rails/plugins/theme_support
It will probably need some work to support Rails 2.3.
Update: Looks like there's a rewrite: https://github.com/dasil003/rails-multisite
Sounds like you want to make the 'base' app a plugin and use that in each of your site apps. You can use something like svn-extern so it's automatically updated whenever something changes.

Is it possible to create sub-applications in Ruby on Rails 3 or something like slices from Merb?

Does Rails 3 have anything akin to slices in Merb, or areas in Django where there is a layer of organization above the controller? I heard at some point that they may allow hosting one rails app within another but I can't find any information on that in the pre-release material. Any hints on how to do something like this?
You're right there doesn't seem to be a lot of official documentation on it yet. But yes, you can have application slices -- they're called engines in Rails. Actually they've been available in Rails since 2.3. Currently, you basically make a plugin that has a complete application structure and set up your routes in there to "mount" your app against a specific URL. In Rails 3, engines are basically first-class objects in the Rails stack. I believe they can still be plugins but you will also be able keep it away from your application in a separate gem and require it in your application much more easily. You should be able to find stuff pretty easily on teh Google, but here's an oft-linked but informative reference: https://gist.github.com/af7e572c2dc973add221

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