Scope Builder

Build up named scopes conditionally.

Install

First specify it in your Rails config.

config.gem 'ryanb-scope-builder', :lib => 'scope_builder', :source => 'gems.github.com'

And then install it.

rake gems:install

Rails 2.1 or later required.

Usage

This gem adds the scope_builder method to all Active Record models. A builder behaves exactly like any other named scope except that calling other named scopes on it will alter the builder itself rather than returning a new named scope.

builder = Product.scope_builder
builder.released.visible # call a couple named scopes to change builder
builder.cheap if only_show_cheap_products? # build scopes conditionally

The scope_builder method can also take a block which will return the builder. This is useful when you are using the builder in a model search method.

# in product model
def self.search(options)
  scope_builder do |builder|
    builder.released.visible
    builder.cheap if options[:cheap]
  end
end

The scope_builder method can also be called on an existing scope.

products = Product.released.visible
builder = products.scope_builder
builder.cheap if only_show_cheap_products?

Development

This project can be found on github at the following URL.

github.com/ryanb/scope-builder/

If you would like to contribute to this project, please fork the repository and send me a pull request.