Community contributions, tips, and corrections to the documentation. (1708 notes)
Nowadays all the functionalities in Rails are built as Ruby gems. For example we can use devise gem for the authentication part of the application. It’s like a package or library that is written in Ruby programming language. Moreover it can be imported and used by others in their programs.
Step 1 B...
There are basically two levels of accessing network services in case of rails .
The socket and network libraries are such important parts of integrating Ruby applications with the Internet and other communications-based environments.
One is through socket libraries provide low level access to conn...
It is also possible to specify that +add_foreign_key+ should be added to the schema: add_reference(:products, :supplier, foreign_key: true)
With activerecord-import, you’d just add your records to an array and call import:
records_to_import = pricing_data.map do |location, price|
Inventory.new(location: location, price: price)
end
Inventory.import records_to_import
Before v3.2.1, this method was in ActiveRecord::Base.create .
After v3.1.0, this method moved to ActiveRecord::Persistence::ClassMethods#create .
I use what @equivalent suggests a lot but be careful, you MUST state the direction otherwise methods like take/last/first will fail silently!
StatusChange.arel_table['created_at']. asc
not:
StatusChange.arel_table['created_at']
fruits = ['apple','orange'']
fruits.each do |fruit| puts "A fruit of type: #{fruit}" end
What's the intention for doing that?
If your value or text method requires a parameter, like to_s(:select) then you need to create a separate method that references that in your model, like:
def to_s_select
to_s(:select)
end
You can't pass it in as a string like 'to_s(:select)'....
keredson is still a little off on the behavior.
Where in reality this would grab the “first” record (say w/ email “[email protected]”), and change its email to “[email protected]”, a fairly surprising action that doesn’t obviously fail, leading to some pretty subtle bugs.
This isn't right, as if...
If a block exists, will return true if any records in the relation is true for the given block. Otherwise, returns true is there are any records.
Selects the first record within a relation if it exists, otherwise creates a new record with the optional attributes.
rajivekjain:
"A, B, and C" is correct in English, and is preferred by most style manuals. "A, B and C" is also correct in English. See https://en.wikipedia.org/wiki/Serial_comma
By default :on_update and :on_delete have :restrict value.
For ordering on the attribute of an associated model you can add joins to query and merge order scope: Product.joins(:category).merge(Category.order(priority: :desc))
Dino’s comment was almost certainly due to a misunderstanding of the API, a mistake I made myself the first time I used it, and one I've witnessed multiple others make as well.
The fact that this method takes an attributes parameter leads one to think the passed params are the criteria for the sele...
I very much doubt that dino's comment was ever correct, but it certainly isn't correct now. The behavior liantics describes is correct.
http://apidock.com/rails/ActionDispatch/Request/body <- request body link
There is way to have text values for enum. It is useful to have localized select options and latin values in database.