class ThinkingSphinx::Index::FauxColumn

Instances of this class represent database columns and the stack of associations that lead from the base model to them.

The name and stack are accessible through methods starting with __ to avoid conflicting with the #method_missing calls that build the stack.

Public Class Methods

coerce(columns) click to toggle source
# File lib/thinking_sphinx/index/faux_column.rb, line 18
def self.coerce(columns)
  case columns
  when Symbol, String
    FauxColumn.new(columns)
  when Array
    columns.collect { |col| FauxColumn.coerce(col) }
  when FauxColumn
    columns
  else
    nil
  end
end
new(*stack) click to toggle source

Create a new column with a pre-defined stack. The top element in the stack will get shifted to be the name value.

# File lib/thinking_sphinx/index/faux_column.rb, line 13
def initialize(*stack)
  @name  = stack.pop
  @stack = stack
end

Public Instance Methods

__name() click to toggle source

Can't use normal method name, as that could be an association or column name.

# File lib/thinking_sphinx/index/faux_column.rb, line 34
def __name
  @name
end
__path() click to toggle source
# File lib/thinking_sphinx/index/faux_column.rb, line 45
def __path
  @stack + [@name]
end
__stack() click to toggle source

Can't use normal method name, as that could be an association or column name.

# File lib/thinking_sphinx/index/faux_column.rb, line 41
def __stack
  @stack
end
is_string?() click to toggle source

Returns true if the stack is empty and if the name is a string - which is an indication that of raw SQL, as opposed to a value from a table's column.

# File lib/thinking_sphinx/index/faux_column.rb, line 53
def is_string?
  @name.is_a?(String) && @stack.empty?
end
method_missing(method, *args) click to toggle source

This handles any 'invalid' method calls and sets them as the name, and pushing the previous name into the stack. The object returns itself.

If there's a single argument, it becomes the name, and the method symbol goes into the stack as well. Multiple arguments means new columns with the original stack and new names (from each argument) gets returned.

Easier to explain with examples:

col = FauxColumn.new :a, :b, :c
col.__name  #=> :c
col.__stack #=> [:a, :b]

col.whatever #=> col
col.__name  #=> :whatever
col.__stack #=> [:a, :b, :c]

col.something(:id) #=> col
col.__name  #=> :id
col.__stack #=> [:a, :b, :c, :whatever, :something]

cols = col.short(:x, :y, :z)
cols[0].__name  #=> :x
cols[0].__stack #=> [:a, :b, :c, :whatever, :something, :short]
cols[1].__name  #=> :y
cols[1].__stack #=> [:a, :b, :c, :whatever, :something, :short]
cols[2].__name  #=> :z
cols[2].__stack #=> [:a, :b, :c, :whatever, :something, :short]

Also, this allows method chaining to build up a relevant stack:

col = FauxColumn.new :a, :b
col.__name  #=> :b
col.__stack #=> [:a]

col.one.two.three #=> col
col.__name  #=> :three
col.__stack #=> [:a, :b, :one, :two]
# File lib/thinking_sphinx/index/faux_column.rb, line 102
def method_missing(method, *args)
  @stack << @name
  @name   = method
  
  if (args.empty?)
    self
  elsif (args.length == 1)
    method_missing(args.first)
  else
    args.collect { |arg|
      FauxColumn.new(@stack + [@name, arg])
    }
  end
end
to_ary() click to toggle source
# File lib/thinking_sphinx/index/faux_column.rb, line 57
def to_ary
  [self]
end