I want to create a sms payment engine and reuse it in several applications. It would be best to be able to just copy/paste one directory, maybe configure some minor stuff and just have it working (with views, controllers, etc.).
What's the best way to do this? Of course I'm not asking about this sms thing but about the way to create an isolated piece of application. It's something like a helper application inside of the major application.
There a three ways to build Rails extensions : plain-old ruby code, Railties and Engines.
Railties and Engines allow you to interact with the Rails framework during the initialization using hooks and therefore extend Rails. Actually, every major Rails component (ActiveRecord, ActionPack, etc.) is a Railtie.
The main difference between a railtie and a Rails engine is that an engine can define its own configuration, models, controllers and views. In a way, an engine is a Rails application you can deploy in another one. In your case, I guess a Rails Engine would be the right choice.
Whatever the option you use, you will have to build a gem to distribute your extension and share it across projects.
Here is a gist explaining both the Railtie and Engine concepts
A guide to starting your own rails engine.
Enginex, a command line tool which creates a Rails 3 Engine
I guess the best way to reuse your code is putting them to a gem, then install that gem.
I think the best way to extract reusable part of your application is to create a RubyGem. You can find a tutorial about creating RubyGems here. And there is a Jeweler, a very nice tool to create RubyGems. More about Jeweler, you can find here
Related
I have installed CKeditor for my Rails app and while doing the Formatting, the Formatted code does not display in the screen, instead, HTML is rendered, like this
<h2><strong>In this project</strong> you’ll create a simple blog system and learn the basics of Ruby on Rails including: Models, Views, and Controllers (MVC) Data Structures & Relationships Routing Migrations Views with forms, partials, and helpers RESTful design Using Rails plugins/gems The project will be developed in five iterations. I0: Up and Running Part of the reason Ruby on Rails became popular quickly is that it takes a lot of the hard work off your hands, and that’s especially true in starting up a project. Rails practices the idea of "sensible defaults" and will, with one command, create a working application ready for your customization. Setting the Stage First we need to make sure everything is set up and installed. See the Environment Setup page for instructions on setting up and verifying your Ruby, Rails, and add-ons. This tutorial was created with Rails 4.0.0, and may need slight adaptations for other versions of Rails. Let us know if you find something strange! From the command line, switch to the folder that will store your projects. For instance, I use /Users/jcasimir/projects/. Within that folder, run the rails command:</h2>
Use the html_safe method
So, something like:
puts my_variable.html_safe
Lots more info here: http://yehudakatz.com/2010/02/01/safebuffers-and-rails-3-0/
I have a number of view helpers I use on almost every project, a set of useful rake tasks, minor extensions to active record, extensions to some gems (inherited_resources).
I'm wondering, what would be a good way to manage these 'snippets'? I wouldn't want to manage a gem for each snippet, or even a gem for each 'type' of snippet. Would it suffice to bundle this into a personal gem? Maybe add the option to specify which helpers/extensions to include in the project?
I could use a 'template' application which I could bundle with this code, but the problem here is if I update a snippet on one project, I want to be able to rollout that update on all projects with minimal effort (i.e. bundle update).
With your requirements, I would bundle it all in a base-zenph-gem and use it in every one o your projects, as it is the best way to have synchronized code over different projects.
Also, make a good documentation for it, as if anyone inherits one of those projects would love to know what is going on.
Instead of a gem with Rails you can create an engine which contains reusable functionality, then you can specify the use of the engine within your applications.
You can read more about it in the Rails documentation: Rails Engines
What is the difference between the two and when one should be used instead of the other?
An Engine in rails terminology is a actually a subapplication of a web-application. For instance, something like a blog, a forum, or simple authentication: these are not full-blown applications, but pages/views/controllers/models that can be added to any rails application.
In rails2 this would be done using a plugin. Now since rails3 an engine can be packaged in a gem.
A gem is a ruby library, which can be found on http://rubygems.org and it is the standard (only) way to package and distribute ruby code to other rubyists.
So to conclude:
A gem: is a generic library, which can be easily installed, which are version-managed, have dependencies and such.
An engine: is a sub-application of a Rails application, and since Rails 3 these are distributed as a gem (which is awesome!).
So when will you use one or the other:
create a gem if you want to share ruby-functionality
create an engine (and package it in a gem) if you have parts of your rails application that can be used more generally.
Hope this helps.
I'm trying to understand what exactly the above (in my question's Title) means? This is taken directly from the SpreeCommerce.com project:
If you’re an experienced Rails developer you may be wondering where your app directory is. Spree actually runs as an embedded Rails app inside of your gem. How do you customize things then? We’ll cover that later in extensions.
Source: http://spreecommerce.com/documentation/getting_started.html
Can someone further explain what exactly it means when a Rails app is run "inside of your gem"
With the gem spree, you can install your application and use it. A lot of application need download complete package to install it. When the gem spree, you don't. So it's more easier to install spree on your server.
The phrase you quote is poorly written and not particularly useful. What you should take away is that Spree is structured different from the majority of Rails plugins.
Typical plugin:
your rails app <-- plugin functionality
A Spree app:
spree rails app <-- your site specific code
Typically, most Rails plugins are installed in the vendor/plugins directory of your Rails app. Some additional functionality is added by classes and modules that you can then reference in your code (subclassing a ResourceController, for instance).
Spree does not work in this way. Because, presumably, there is so much configuration code for Spree, each Spree instance creates a separate Rails app -- one that's missing some of the more important parts of a Rails app (such as the app directory). All of your site specific code goes in the vendor/extensions/site directory. This means you don't have to worry about editing any of the Spree-specific code (since it's all in a different directory) and you can more easily put your own code under source control.
As a Rails developer I feel a bit stupid asking this question but hopefully I will learn something new and someone can put me out of my misery! In my rails applications I use (other peoples) gems all the time, I also use plugins from the community or my own.
I understand the benefits of use gems over plugins as they are version-able, segmented, system wide, easier to manage and share etc etc but I don't really know how to go about making a gem for my rails apps!?
Do you always start with a plugin and convert it to a gem, I've seen the words 'package it as Gem'. Also the gem I'm thinking of building would be no good in a normal ruby program, it's only useful to rails apps. I'm not even sure if the semantics of that make sense, 'RubyGem' that will only work in a rails application!?
I would like to create a gem (if that's what I should use?) for a discrete piece of functionality for my rails apps. It will need to add a database migration, new routes and provide controllers and views or useful view helpers. I'm know I can achieve this via a plug-in but would just like to know how/why to do it as a 'Ruby Gem'?
To avoid the risk of Over-engineering, I usually start with the feature I need directly into the application. Then, as soon as I need to use the same feature into another project, I check whether it is worth to extract it into a plugin or even a separate application providing an API.
Plugins and Gems are often interchangeable. Gems provides several significant advantages in terms of reusability and maintainability.
On the other side, there are some specific known issue. For instance, a Rails app actually can't load rake tasks defined into a plugin packaged as a Gem.
Almost every Rails plugin can be packaged as a Gem.
For instance, take my tabs_on_rails plugin.
You can install it as a Gem specifying the dependency on environment.rb. Or you can use script/plugin install command as you would expect.
If you want to achieve the same result, make sure to follow the standard Gem layout and provide the init.rb initialization script required by Rails.
Also, you might want to create an install.rb and uninstall.rb file to include the post-install and post-uninstall hooks when the plugin is installed as a standard Rails plugin.
Last but not least, if you package a plugin as Gem you can reuse it in non-Rails projects and provide Rails-specific initializations using the init.rb file. Non-Rails applications will simply ignore it.
If you want to make a plugin for Rails, https://peepcode.com/products/rails-2-plugin-patterns gives you a good start. After that, make the plugin into a gem.
To make a gem, this resource http://railscasts.com/episodes/183-gemcutter-jeweler will be helpful.
As of 2013 you'll want to use Bundler and the following tutorials:
#245 New Gem with Bundler -
RailsCasts
Make your own gem - RubyGems
Guides
Take a look at Jeweler. Jeweler gives you a set of rake tasks to make gem versioning and building very easy.