Basically because http://en.wikipedia.org/wiki/Null_Object_pattern. It's often the case that systems have to deal with "N" possible changes, where N is between 0 and 1. e.g. I might have a procedure to gradually build up a list of things to change, starting with {} and appending to it if certain conditions are met. It wouldn't be an exceptional situation if none of those conditions are met.
On Thursday, 7 May 2015 18:24:50 UTC+1, Rafael Mendonça França wrote: > > Are not both cases invalid input? Why should we accept empty hashes? > > On Thu, May 7, 2015 at 2:14 PM Michael Mahemoff <[email protected] > <javascript:>> wrote: > >> The following will return an error: >> >> > Post.first.update_columns({}) >> ArgumentError: Empty list of attributes to change >> >> I think that's surprising, because I see update_columns as an analogue to >> update_attributes, just without callbacks happening. An empty hash for the >> latter is fine: >> >> > Post.first.update_attributes({}) >> true >> >> So shouldn't update_columns support an empty hash too? In the rare cases >> where callbacks should be avoided and this is needed, it would save having >> to make a special-case check to prevent the error. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Ruby on Rails: Core" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at http://groups.google.com/group/rubyonrails-core. >> For more options, visit https://groups.google.com/d/optout. >> > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/rubyonrails-core. For more options, visit https://groups.google.com/d/optout.
