method

with_scope

v2.0.1 - Show latest stable - 1 note - Class: ActiveRecord::Base

with_scope(method_scoping = {}, action = :merge, &block) protected

Scope parameters to method calls within the block. Takes a hash of method_name => parameters hash. method_name may be :find or :create. :find parameters may include the <tt>:conditions</tt>, <tt>:joins</tt>, <tt>:include</tt>, <tt>:offset</tt>, <tt>:limit</tt>, and <tt>:readonly</tt> options. :create parameters are an attributes hash. class Article < ActiveRecord::Base def self.create_with_scope with_scope(:find => { :conditions => "blog_id = 1" }, :create => { :blog_id => 1 }) do find(1) # => SELECT * from articles WHERE blog_id = 1 AND id = 1 a = create(1) a.blog_id # => 1 end end end In nested scopings, all previous parameters are overwritten by the innermost rule, with the exception of :conditions and :include options in :find, which are merged. class Article < ActiveRecord::Base def self.find_with_scope with_scope(:find => { :conditions => "blog_id = 1", :limit => 1 }, :create => { :blog_id => 1 }) do with_scope(:find => { :limit => 10}) find(:all) # => SELECT * from articles WHERE blog_id = 1 LIMIT 10 end with_scope(:find => { :conditions => "author_id = 3" }) find(:all) # => SELECT * from articles WHERE blog_id = 1 AND author_id = 3 LIMIT 1 end end end end You can ignore any previous scopings by using the <tt>with_exclusive_scope</tt> method. class Article < ActiveRecord::Base def self.find_with_exclusive_scope with_scope(:find => { :conditions => "blog_id = 1", :limit => 1 }) do with_exclusive_scope(:find => { :limit => 10 }) find(:all) # => SELECT * from articles LIMIT 10 end end end end

Show source

# File activerecord/lib/active_record/base.rb, line 1575
        def with_scope(method_scoping = {}, action = :merge, &block)
          method_scoping = method_scoping.method_scoping if method_scoping.respond_to?(:method_scoping)

          # Dup first and second level of hash (method and params).
          method_scoping = method_scoping.inject({}) do |hash, (method, params)|
            hash[method] = (params == true) ? params : params.dup
            hash
          end

          method_scoping.assert_valid_keys([ :find, :create ])

          if f = method_scoping[:find]
            f.assert_valid_keys(VALID_FIND_OPTIONS)
            set_readonly_option! f
          end

          # Merge scopings
          if action == :merge && current_scoped_methods
            method_scoping = current_scoped_methods.inject(method_scoping) do |hash, (method, params)|
              case hash[method]
                when Hash
                  if method == :find
                    (hash[method].keys + params.keys).uniq.each do |key|
                      merge = hash[method][key] && params[key] # merge if both scopes have the same key
                      if key == :conditions && merge
                        hash[method][key] = [params[key], hash[method][key]].collect{ |sql| "( %s )" % sanitize_sql(sql) }.join(" AND ")
                      elsif key == :include && merge
                        hash[method][key] = merge_includes(hash[method][key], params[key]).uniq
                      else
                        hash[method][key] = hash[method][key] || params[key]
                      end
                    end
                  else
                    hash[method] = params.merge(hash[method])
                  end
                else
                  hash[method] = params
              end
              hash
            end
          end

          self.scoped_methods << method_scoping

          begin
            yield
          ensure
            self.scoped_methods.pop
          end
        end

January 14, 2010

0 thanks

:find takes more keys than written

The documentation says that the :find keywords “may include the :conditions, :joins, :include, :offset, :limit, and :readonly options”. Note that this does not mean that only those options are supported. :sort also works like it should, for example.

with_scope

Related methods

:find takes more keys than written

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