How to nest a Rails application into another rails application - ruby-on-rails

Lets say have a main app, that also has a blog, I like to keep the "blog" part of the app as a separate rails app and re-use it in other rails apps as well.
How should I do it?

The currently popular method to do what you are trying to achieve is to use Engines. Engines basically let you mount one application inside another, allowing you to do anything from add a method or two, to adding a complete blog. The official guides have a very nice step-by-step guide to getting started, and there are many good unofficial guides, as well. An engine basically consists of a little bit of initialization code, the application code, and a dummy application for testing and development. It might look intimidating, at first, but it's much easier than it sounds, at first. Good luck

Related

How to make a blog application that plugs into other rails applications?

I want to have a blog functionality for some of the applications I have, Instead of developing and maintaining them as part of each application, I would like to develop a blog application and plug it right into other applications and maintain a single code base.
What approach should I take to accomplish this? Or Is there a gem that already does this?
Thanks.
A Rails engine sounds like your best bet. An engine is an application that provides functionality to its host application. Getting Started with Engines guide is a great place to start and just so happens to guide you through the process of creating a blog engine. There are such engines that exist in the wild, such as Blogit. Whatever you decide, running through the engine guide would give you a good understanding of how engines work.

Spree as a mountable engine

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!

Rails Ruby Gems vs Pure Development When Generating A Rich Blog

Some ruby gems like jekyll, toto and webby offer out of the box blog-type integration into your ruby app. Another way of developing a rich web blog-type application is to build and model the application yourself using pure ruby and rails practices. (e.g creating an Article and User model). The first offers out of the box features the 2nd option offers more customization and control.
In people's experience on Stack Overflow, which would be the best route and what would people consider when making the decision to use a gem out of the box versus going alone?
All of the gems you mentioned take static, markdown/textile/etc files and turn them into HTML websites. They take different approaches to it, with jekyll spitting out the finished website for hosting, toto doing the converting and routing on request, and webby doing the same as jekyll mostly.
If you're using Rails, it's important to note that none of these will integrate into your application well. They're built to more-or-less operate on their own.
Generally speaking, if a gem has the functionality you need, use it. They are not equivalent to plugins you find for Wordpress and Drupal where they are typically low-quality, buggy, poorly documented, etc. More often than not, gems simply add a couple modules that you can integrate into your application how you like.
On the other hand, a basic blog is pretty quick and simple in Rails, especially considering you've got a handy walkthrough guide straight from the Rails documentation on how to do it.
If you're new to Rails and want tight integration with your app, it's probably best to bake your own blog features.
This will take some time to do, but its worth it to learn how things really work.
If you're more seasoned, just look at the gem's API and documentation and decide if it does what you want it to do and if you're comfortable with how to integrate it. If so, it'll save you time.
One other consideration: who will be using the blog? Is it for internal use, and programmers will be the ones updating it? If that's the case, then you can make it very easy by not worrying about a lot of aesthetic polish in the back-end. Conversely, if you're making an app that includes a blogging component for the general public you might want it to feel more polished. In this case a gem might save you a lot of time.
It depends on your application.

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

Does a "vertical" framework for RoR make sense?

I have been spending some time creating what I called a framework.
It was aimed at the creation of quiz likes games. It was supposed to have two players syncronized and present them a question to solve, etc.
I would like it to be fully customizable so I tried to develop components that can be put in or out of the pages. In the end the elements became slim ruby methods to add a whole bunch of Javascript and CSS to the pages.
Still the Javascript needs to connect to Ruby so methods supporting it are created but they will only be present when the component is present. Some components depend on one another making everything overly complex.
And after this attempt I wonder, is there is not a better and easier way to make a framework aimed to one kind of application on RoR? Or is the concept flawed or RoR in some way flawed?
Ruby on Rails is a framework on its own accord and is "opinionated software". This means that the writers of Rails looked at what would make most sense for creating a web application to them. Many people support the original developers views and so use Rails for their projects as well.
I think your concept of creating a quiz is a good one, but first you need to understand the rails stack. Depending on what you need exactly, you can create either an engine, plugin or whatever.
What I have seen a lot is that you specify what you need in your controller. (How you do that is up to you). All that information is stored in a class variable and transferred to the view where you can render everything you need with some helpers. The hard part is making it all generic enough to be reusable.
But, maybe Rails isn't the right tool for you. Maybe you need something more lightweight like Merb or even Sinatra.
There is no 'flaw' in Rails. Rails is not the 10**1000-in-one tool Java is. It's a framework that tries to do one way very good in a particular way. I think Rails can be the right tool for you, but you need to be skilled enough to wield the tool :)

Resources