Module: VestalVersions::Versions

Defined in:
lib/vestal_versions/versions.rb

Overview

An extension module for the has_many association with versions.

Instance Method Summary collapse

Instance Method Details

#after(value) ⇒ Object

Returns all version records created after the version associated with the given value.

This is useful for dissociating records during use of the reset_to! method.



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# File 'lib/vestal_versions/versions.rb', line 46

def after(value)
  return [] if (number = number_at(value)).nil?
  where("#{table_name}.#{connection.quote_column_name('number')} > #{number}").to_a
end

#at(value) ⇒ Object

Returns a single version associated with the given value. The following formats are valid:

  • A Date or Time object: When given, to_time is called on the value and the last version record in the history created before (or at) that time is returned.

  • A Numeric object: Typically a positive integer, these values correspond to version numbers and the associated version record is found by a version number equal to the given value rounded down to the nearest integer.

  • A String: A string value represents a version tag and the associated version is searched for by a matching tag value. Note: Be careful with string representations of numbers.

  • A Symbol: Symbols represent association class methods on the has_many versions association. While all of the built-in association methods require arguments, additional extension modules can be defined using the :extend option on the versioned method. See the versioned documentation for more information.

  • A Version object: If a version object is passed to the at method, it is simply returned untouched.



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# File 'lib/vestal_versions/versions.rb', line 65

def at(value)
  case value
    when Date, Time then where("#{table_name}.created_at <= ?", value.to_time).last
    when Numeric then find_by_number(value.floor)
    when String then find_by_tag(value)
    when Symbol then respond_to?(value) ? send(value) : nil
    when Version then value
  end
end

#before(value) ⇒ Object

Returns all version records created before the version associated with the given value.



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# File 'lib/vestal_versions/versions.rb', line 38

def before(value)
  return [] if (number = number_at(value)).nil?
  where("#{table_name}.#{connection.quote_column_name('number')} < #{number}").to_a
end

#between(from, to) ⇒ Object

Returns all versions between (and including) the two given arguments. See documentation for the at extension method for what arguments are valid. If either of the given arguments is invalid, an empty array is returned.

The between method preserves returns an array of version records, preserving the order given by the arguments. If the from value represents a version before that of the to value, the array will be ordered from earliest to latest. The reverse is also true.



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# File 'lib/vestal_versions/versions.rb', line 29

def between(from, to)
  from_number, to_number = number_at(from), number_at(to)
  return [] if from_number.nil? || to_number.nil?

  condition = (from_number == to_number) ? to_number : Range.new(*[from_number, to_number].sort)
  where(:number => condition).order("#{table_name}.#{connection.quote_column_name('number')} #{(from_number > to_number) ? 'DESC' : 'ASC'}").to_a
end

#number_at(value) ⇒ Object

Returns the version number associated with the given value. In many cases, this involves simply passing the value to the at method and then returning the subsequent version number. Hoever, for Numeric values, the version number can be returned directly and for Date/Time values, a default value of 1 is given to ensure that times prior to the first version still return a valid version number (useful for reversion).



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# File 'lib/vestal_versions/versions.rb', line 80

def number_at(value)
  case value
    when Date, Time then (v = at(value)) ? v.number : 1
    when Numeric then value.floor
    when String, Symbol then (v = at(value)) ? v.number : nil
    when Version then value.number
  end
end