Class: AWS::Record::HashModel::Scope

Inherits:
Scope
  • Object
show all
Defined in:
lib/aws/record/hash_model/scope.rb

Overview

The primary interface for finding records with AWS::Record::HashModel.

Getting a Scope Object

You should normally never need to construct a Scope object directly. Scope objects are returned from the AWS::Record::HashModel finder methods # (e.g. shard and limit).

books = Book.limit(100)
books.class #=> AWS::Record::HashModel::Scope

Scopes are also returned from methods defined with the scope method.

class Book < AWS::Record::HashModel
   scope :sampling, limit(10)
end

Book.sampling #=> returns a scope that limits to 10

Chaining Scopes

Scope objects represent a request, but do not actualy make a request until required. This allows you to chain requests

# no request made by the following 2 statements
books = Book.shard('books-1') # what table to search
books = books.limit(10) # how many records to fetch

books.each do |book|
  # yields up to 10 books from the table 'books-1'
end

The following methods returns a scope that can be chained.

Terminating Scopes

To terminate a scope you can enumerate it or call #first.

# terminate a scope by enumerating
Book.limit(10).each {|book| ... }

# terminate a scope by getting the first record
Book.shard('books-1').first

Instance Attribute Summary

Attributes inherited from Scope

#base_class

Method Summary

Methods inherited from Scope

#count, #each, #find, #first, #limit, #new, #shard

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class AWS::Record::Scope