I want to populate a preferences table when a user is created. I can make a lash up version within the controller easily enough but would like something neater.
Can one do the same sort of thing with fixtures within a running application? If so how?
You could search for a gem. I've used https://github.com/FooBarWidget/default_value_for some time ago for a similar thing. It's a nice and clean solution.
In the end I simple defined an array in the model and array.each -ed it. Not perhaps the most elegant but still have all the values in one place for editing.
Related
It seems like a silly question, but anyway:
I have a model with lets say 10-12 fields (columns) added in different migrations.
When I write code now (model, view, tests) I want to have a list of the column names.
Is there a good way to do so? (other than going to the DB manually and getting the column names)
It seems like an action the developer does quite often, or is it just me
Simply use ActiveRecord::Base#column_names:
Model.column_names
You could do something like:
ModelName.new.attributes.keys
I need to have two (or maybe even more) different create (and update) methods in one controller. I already have views displaying the forms, so I basicaly only need to tell the submit which method to call in the controller. Is that possible? If so, how? Or can I only have one create method and have that method do different things depending on which view called the method?
Thanks
Ignoring the fact that this sounds like a really terrible idea, it's possible. You will need to add some more routes that will match the new actions in your controller. You won't be able to call them 'create' and 'update' because method names must be unique within the same class.
Having said that, I really beg you to rethink your approach. REST, as described in the Rails Getting Started guide, by far the standard for building Rails applications. If you're not familiar with it, I would recommend stopping where you are and reading up on it. Your application will be much easier to build and maintain, and you won't waste time asking structural questions. If you are familiar with it and are choosing to ignore it, then I wish you the best of luck.
you can use this command:
rails g scaffold_controller 'controller_name'
or if spastic method you can use this:
rails generate controller 'controller_name' add new
Let's say that you have an object Book. You can change values of Book in any method inside of your books_controller.rb as long as that method has access to #book.id.
def crazy_create_method
book.create (book_params)
book.save
end
That being said, try to stick to the default new/create methods and if you need to get weird later on it's always easy to call the code belong in whatever method you need. Rails bakes a lot of out of the box functionality into the default REST actions.
book.title = my_title
book.save
I am creating an application where I need to categorize one of my models. There are five categories and they will not change, at least not for now. The object can only have one category at once. My two ideas are:
Create a whole table for adding the categories and add them in the migration file. I would then store the category id in the db for my object. Read about this causing problems with testing so I'm not sure. And, it seems a bit overkill.
Add a constant hash in my model for hosting the categories. I would then store the int key in my object.
Is there any better way I have not thought about? Are there any plugins for creating enums in rails?
Thanks
I have used this plugin https://github.com/adzap/active_enum some time ago and I think it works OK. You should definitely try it.
I'd like to use Thinking Sphinx, but I keep having problems because I have a very large rails project and the search method is used in many of my models. These already existing search methods conflict with Thinking Sphinx's search method. Is there any way around this?
I'm talking thousands of lines of code I would have to change if I had to change my search method to something else. I can't seem to find a way to change the default search method in Thinking Sphinx though either.
Thanks.
Just answered this on the TS list, but happy to answer here as well :)
There isn't any inbuilt way to do this, but in theory it could be possible. Firstly - Thinking Sphinx adds the class-level search method when you call define_index on a model - so, if you define your own search method after that, it'll overwrite the Thinking Sphinx version.
This means you could just define a new method that does the same thing - here's the code for Model.search:
def self.search(*args)
ThinkingSphinx::Search.new *search_options(args)
end
Which you could easily rename to something else:
def self.sphinx_search(*args)
ThinkingSphinx::Search.new *search_options(args)
end
The one possible catch with this is that Thinking Sphinx may have expectations internally on the search method existing and behaving as normal. I'm not sure - but give this a spin and see how you go!
Update:
As it turns out, the above suggestion doesn't cover all situations and it's still buggy. So, I think the fallback solution is to fork Thinking Sphinx, change the method names, and use your version instead of the canonical one.
Normally rails loads data with a :select => "*" from the database. I know I could change this. But I'd like to go another way: always only select "id" and load the attributes automatically later on when they are needed.
Example:
accessing user.description should if it's been loaded yet. if not, trigger a "SELECT description FROM users WHERE id=#{self.id}" and set it.
Anyone know if there's a rails plugin which does this? Or how to implement it?
Thanks,
Corin
I wrote a Rails plugins that does exactly this lazy_columns. Notice that a much better approach is to create a new model with the big columns you want to load on demand (since Rails load related objects lazily by default).
A quick google search turned up this, but I'm with glongman. I can't imagine what kind of performance issue would require this...
It is wise to just refactor your main "huge blob" fields into a separate model (like BookBody) which is usually not needed when operating with models in bulk. Alternatively, you can use the :select option on finders
BookWithHugeBlobOfText.find(:first, :select=>"only,small,columns")
Records selected that way will be readonly since the Rails philosophy says (and rightfully so!) that you need to have all data on the model to validate it. Lazy loading would be a nice to have, but as it stands now I would discourage you from using monkeypatch plugins for this.
Another option would be to create a SQL view which would only contain the lightweight fields and run your ops from there.