On 2 July 2015 at 11:07, Federicko <[email protected]> wrote: > OK, so I have modified the code following Colin's suggestion. > Check it out: > > In the controller, my action is as follows: > > def rank > @this_article = Article.find(params[:id]) > > if (params[:rank] == 'up') > @this_article.rankup(params[:rank]) > else > @this_article.rankdown(params[:rank]) > end > > redirect_to articles_path() > end > > > In my model, I have rankup and rankdown instance methods then I have a > private method: > > def rankup(rank) > swap_rank(self.id, self.ranking, rank) > > self.ranking = self.ranking - 1 > self.save > end > > def rankdown(rank) > swap_rank(self.id, self.ranking, rank) > > self.ranking = self.ranking + 1 > self.save > end > > private > > def swap_rank(id, ranking, rank) > if (rank == 'up') > @affected_article = Article.find_by(ranking: ranking.to_i-1) > @affected_article.ranking = @affected_article.ranking + 1 > else > @affected_article = Article.find_by(ranking: ranking.to_i+1) > @affected_article.ranking = @affected_article.ranking - 1 > end > > @affected_article.save > end > > I like this way. It is clean and simple. > All the code that make changes to the db resides in the model and the > controller simply determines which model method to call. >
A few points. What happens if params[:rank] is not specified or is not valid? What would the effect be if self.save in rankup failed (a validation failure for example), or the affected_article.save failed? What would the affect be if your app or the server crashed between the two saves? As I previously suggested wrap the whole thing in a transaction in order to recover from this sort of problem. In order to do that change swap_rank to do the complete operation including both saves, possibly by passing it the two articles to be swapped. Colin -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAL%3D0gLu8wSSx8F0SqUR6fBxnZb9XD%3DHX3LAHwppi5vDYiMj2Xw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
