I am using Ruby on Rails 3.2.9 and Ruby 1.9.3-p125. After my previous question I ended up that I have an issue on metaprogramming a self-implemented acts_as_customizable plugin since the related code has side effects on other classes than that "acting as customizable".
To summarize the issue: the acts_as_customizable method stated for an Article model "internally" (through metaprogramming) adds a customize method to a Comment model and, in order to save time, Rails doesn't load all those classes on startup making the application to raise a NoMethodError - undefined method 'customize' for #<Comment:0x0...> until the Article class is loaded.
A proposed solution was to require_dependency 'article' in the Comment model, but I am looking for another way (maybe, better of the proposed one) to have the application to work as it is doing right now, but without any issue as-like that explained in this question. That is, I would like to keep a *short code** and the same behavior but using a more "appropriate" way to make things, maybe changing the loading process of classes or planning a big refactoring for the whole code, if necessary.
How should I handle this situation? What do you think about?
Update: After some study, I discovered that the problem arises only in development mode since the config.cache_classes is set to false making classes to be reloaded on every request.
Note: I want point out that metaprogramming is very usefull in my case and Article and Comment classes are highly related one to another in the aspect of my conception of "customization". So I would like to find a solution alleviating changes to the underling behavior.
* In my case, metaprogramming (even if it has side effects) makes me to avoid a lot of code statements.
Related
I'm reading active_support documentation and it says that whenever there's a controller action called, rails searches for corresponding helper class. If there's no such class, an exception is thrown, caught and possibly rethrown.
I'm curious how (in)efficient is this and should I just have empty helper classes for the sake of not throwing exceptions in the background of my code?
I'm not trying to do any kind of premature optimization, I'm just looking into internals of rails and was curious as to why would they make it so that it always throws exception when there's no helper defined.
Here's the related documentation:
http://guides.rubyonrails.org/active_support_core_extensions.html#extensions-to-nameerror
Any insights and more details would be appreciated.
Thanks!
I'm going to answer from a place of "wishful thinking", not from any particular knowledge about Rails internal code. I know (and love) that Rails was built with the busy developer in mind: it was designed by someone who hates repeating himself, with an ethos of DRY code and sensible defaults in mind.
So given that, it sounds like a horrible idea to worry about setting up empty helper classes just for the sake of making the Rails startup code more efficient. That's very opposite to the intentions that Rails was built on, and I think you can count on the community holding to those intentions going forward.
I'm rewriting one old app - Rails 1.2.6 :)) - completely in Rails 4... so you can imagine the information overload.
It's going quite well so far but I'm currently struggling with one task that should be pretty obvious but it lacks proper documentation and there are just too many blogs with different solutions to this issue.
I have a custom class with custom text conversion functionality (using Redcloth, autolinker, Sanitize etc.), let's call it Textilize class. It's used in models as well as controllers so I guess the best solution would be to create a gem from it. I want to attack gem creation later though since it's just a simple one-file class.
So for now I just added textilize.rb file to /lib directory and added config.autoload_paths += %W(#{config.root}/lib).
It works fine and I can now use it in the app without requiring it in the models and controllers.
Is this a good practice in Rails 4? Is it thread-safe?
If not, is there a way to refactor it without creating a complete gem for now?
Thanks!
"Is this a good practice?" I think it is.
"Is it thread-safe?" I don't know
Any other way? I will use your solution if the lib is crossing Model and Controller and it is simple. If it get rather complex, I will create a plugin. If it is complex and can be extended to be useful on other apps, I will create a gem.
I've finally started making a Rails app from scratch and I'm getting the hang of it, but the only problem is that making all the models/controllers is getting really repetitive and totally throwing the whole DRY concept out of the window as I'm basically copying controllers and renaming them/adding/disabling fields. I have:
Projects
People
Tasks
Messages
etc and the first three need to pretty much have the same layout and CRUD. Is the only way of not having to manually create all of the actions/views each time scaffolding? If so, what other things does scaffolding generate that I need to be aware of. I've been cautious of using it in the past because I wanted to know how my application worked in the tutorials.
In my opinion scaffolding is not for new rails programmers, it should only be used after you figured out rails yourself and with a criticizing approach. It may generate whole files that you have no need, define unneeded routes etc...
You can have a look at the full details of what scaffold creates here
As for the repetitive controllers you are making I could suggest using the gem InheritedResources which eliminates a lot of this duplication (at least while you are at the basic CRUD controller operations)
InheritedResources sets the basic controller index/show/destroy/create/edit actions for you, all you have to do is to inherit from it using:
class ProjectsController < InheritedResources::Base
end
In case you have to, you can override actions by defining them yourself.
It's an excellent point. You generally want to keep your controllers as thin as possible, and certainly thinner than what the scaffolding gives you.
The way I like to think of the scaffolding is that it's good to use for your first feature in a new Rails app as an example of the current best practices and things you might want to know about. After that, however, write your controllers yourself, and factor out any duplication.
For additional ideas, you might want to read/watch...
Objects on Rails
Hexagonal Rails
Architecture the Lost Years
I've been using Rails for a few months now, and I'm quite comfortable writing up a project & manipulating Rails to my needs, etc.
Recently I've been trying to get a little more advanced, so I've attempted to modify/add to the existing rails codebase: add new form helper methods, add a responds_to :pdf method, etc...and I've been having a lot of problems.
The difficulty is learning which code I need to modify; where that code is located, and how to ensure I don't miss related code in other files. I'm guessing there's a way people learn to do this, but at the moment I'm mostly just guessing-and-hoping.
I guess my question is, how do Rails folks go about learning where the code they need to modify is edited & the approach to editing it? It seems like it's just something you need to know from prior familiarity, but I'm guessing there has to be a simple method for understanding where (and what) to edit.
Any ideas appreciated...cheers
I highly recommend Jose Valim's Crafting Rails Applications
You go through advanced projects, building out the types of engines and customizations that will take you to the next level in your Rails development.
From the site:
This book will help you understand Rails 3’s inner workings, including
generators, template handlers, internationalization, routing, and
responders.
What you are asking for is how MVC works. Basicly you can say:
1.) Put logic to the model! The model is the pivot everything turns around.
2.) The Controller is a middleman between the model and the view. You dont put any logic here that isnt related to selecting data from the database that should be displayed in the view. If you use one selection logic more than once create a scope in the Model and use it in the Controller.
3.) The View is only there to display things! You dont put any logic here! All the logic comes from the model and the data comes from the controller. The only logic your using here are loops through arrays of data that should be displayed.
Then you have some things missing. If you have a task that is related to an external service like lets say a SOAP Service you write a class for that too! Just whithout using ActiveRecord::Base inheritance like its generated by the scaffolder. You can call this Class in other models. Dont put this to the controller or copy the code in every class that needs it! Stay DRY (Dont Repeat Yourself). Just write a class for it and include it in the other models!
Another thing thats a Database basic: Dont store data that could be calculated from other fields from the database! You can add methods that calculate the stuff you need but dont start with duplicates.
Just learning rails, developing first app and having trouble finding a straight answer to this question!
I want to keep my models as lean as possible and really only want to use them to represent objects that I might want to render in my views. Therefore, I want to remove some of the logic from one particular model and store it in a separate file. I have seen numerous guides (on this site and others) that suggest the following;
never "require" anything from inside a rails app
Store additional files in the lib folder - they used to be auto loaded in older rails releases but now you need to add an extra line in a config file to get this to happen (Example.
So I added the line, stuck the file in the lib folder, and it all worked fine. So on to the question;
I can't shake the feeling that the fact that I had to go and put some bespoke code into the config file means I'm doing this wrong (given convention over configuration). Why are people having to faff around editing configuration files to get rails to do something so basic?
Is that the best way or are there additional considerations that I'm just not seeing? Should I in fact be creating an "extras" directory rather than still sticking things in lib?
If anyone can point me in the direction of a definitive article on the matter I'd be much obliged!
There is nothing wrong with having non active record models in the model folder. If your domain is best modeled by a business logic layer and a persistence layer, then model it that way in your model folder with appropriate naming conventions. Personally I wouldn't be overly concerned with getting it perfect. Try something and see how you like it.. learn from your mistakes and keep getting better! Above all, enjoy the process.
what I do is this: keep the model logic in the model and keep the controllers as thin as possible
If there are things that should belong to your model but are somewhat distant to it (for example you have an Account model and you're working on some payments system which relates to the Account - for example you might want to call account.has_subscription?, you could use a gem called concerned_with which would split your model's main actions from others like the ones handling payments (this is just an example I recently had to take care of).