This is probably a Ruby questions but since my issue exists in a Rails
validation I thought I''d post here. I have the following validator
validates_each :thumbnail, :regular do |record, attribute, value|
unless value.nil? &&
value.valid?
record.errors.add(
attribute, value.errors.full_messages[0])
end
end
I''m getting a ''nil object when you didn''t expect it
error'' because the
condition is evaluating value.valid?. I was under the impression that if
the first condition (value.nil?) returned True then the second condition
would not be evaluated.
Does anyone know what I''m missing here?
If I rewrite it as:
validates_each :thumbnail, :regular do |record, attribute, value|
unless value.nil?
record.errors.add(
attribute, value.errors.full_messages[0]) unless value.valid?
end
end
it works fine.
Thanks for any education,
William
--
Posted via http://www.ruby-forum.com/.
William LeFevre wrote:> This is probably a Ruby questions but since my issue exists in a Rails > validation I thought I''d post here. I have the following validator > > validates_each :thumbnail, :regular do |record, attribute, value| > unless value.nil? && > value.valid? > record.errors.add( > attribute, value.errors.full_messages[0]) > end > end > > I''m getting a ''nil object when you didn''t expect it error'' because the > condition is evaluating value.valid?. I was under the impression that if > the first condition (value.nil?) returned True then the second condition > would not be evaluated.Logic error I believe. That is an AND condition, therefore if the LHS is true it has to evaluate the RHS. If the LHS was false then it would short circuit the evaluation of the RHS. You probably want a ! in there somewhere. -- Posted via http://www.ruby-forum.com/.
Logic error. Use OR instead of AND. -Derrick Spell On Feb 24, 2006, at 1:35 AM, William LeFevre wrote:> This is probably a Ruby questions but since my issue exists in a Rails > validation I thought I''d post here. I have the following validator > > validates_each :thumbnail, :regular do |record, attribute, value| > unless value.nil? && > value.valid? > record.errors.add( > attribute, value.errors.full_messages[0]) > end > end > > I''m getting a ''nil object when you didn''t expect it error'' because the > condition is evaluating value.valid?. I was under the impression > that if > the first condition (value.nil?) returned True then the second > condition > would not be evaluated. > > Does anyone know what I''m missing here? > > If I rewrite it as: > validates_each :thumbnail, :regular do |record, attribute, value| > unless value.nil? > record.errors.add( > attribute, value.errors.full_messages[0]) unless value.valid? > end > end > > it works fine. > > Thanks for any education, > William > > -- > Posted via http://www.ruby-forum.com/. > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >