I've managed to figure out how to use Rails.
But I don't have enough coding ability.
When I go to another language, I don't think I can apply it ...
I thought, so
I decided to read the Rails source code.
I tried to refer to this. I read the Rails code
To read around Active record First, with shift command f def new Full text search
# frozen_string_literal: true
module ActiveRecord
# = Active Record \Relation
class Relation
MULTI_VALUE_METHODS = [:includes, :eager_load, :preload, :select, :group,
:order, :joins, :left_outer_joins, :references,
:extending, :unscope, :optimizer_hints, :annotate]
SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :reordering, :strict_loading,
:reverse_order, :distinct, :create_with, :skip_query_cache]
CLAUSE_METHODS = [:where, :having, :from]
INVALID_METHODS_FOR_DELETE_ALL = [:distinct, :group, :having]
VALUE_METHODS = MULTI_VALUE_METHODS + SINGLE_VALUE_METHODS + CLAUSE_METHODS
include Enumerable
include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation
attr_reader :table, :klass, :loaded, :predicate_builder
attr_accessor :skip_preloading_value
alias :model :klass
alias :loaded? :loaded
alias :locked? :lock_value
(And omission)
# Initializes new record from relation while maintaining the current
# scope.
#
# Expects arguments in the same format as {ActiveRecord::Base.new}[rdoc-ref:Core.new].
#
# users = User.where(name: 'DHH')
# user = users.new # => #<User id: nil, name: "DHH", created_at: nil, updated_at: nil>
#
# You can also pass a block to new with the new record as argument:
#
# user = users.new { |user| user.name = 'Oscar' }
# user.name # => Oscar
def new(attributes = nil, &block)
block = _deprecated_scope_block("new", &block)
scoping { klass.new(attributes, &block) }
end
alias build new
(Omitted)
def _deprecated_spawn(name)
spawn.tap { |scope| scope._deprecated_scope_source = name }
end
def _deprecated_scope_block(name, &block)
-> record do
klass.current_scope = _deprecated_spawn(name)
yield record if block_given?
end
end
def new(attributes = nil, &block)
block = _deprecated_scope_block("new", &block)
scoping { klass.new(attributes, &block) }
end
alias build new
First of all, vaguely understand
Since we will create a new record, the attribute is nil 2. I'm passing a block argument, where is the block? 3. The _deprecated_scope_block method is defined below, but I don't understand the meaning 4. What is klass?
The doubts are endless Let's search a little more
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