Why does Rails flash [: notice] = "msg" work where: notice => "msg" is not?

Question

Why does Rails flash [: notice] = "msg" work where: notice => "msg" is not? A notification is displayed if I use the following code:

# Case 1 (this works) flash[:notice] = 'Candidate was successfully registered.' format.html { redirect_to :action => "show_matches", :id => @trial.id } 

This does not work:

 # Case 2 (this doesn't) format.html { redirect_to :action => "show_matches", :id => @trial.id, :notice => "Candidate was successfully registered."} 

But in other areas of my application, the described technique works very well:

 # Case 3 (this works) format.html { redirect_to @candidate, :notice => 'Candidate was successfully created.' } 

My layout includes:

 <section id="middle_content"> <% flash.each do |key, value| -%> <div id="info_messages" class="flash <%= key %>"><%= value %></div> <br/> <% end -%> <%= yield -%> </section> 

So my question is why use :notice => "" works in one case, but not in another?

I understand that I did not give you much context, but I believe that my problem is actually very simple.

ps This is similar to this question .

Answer 1

Redirect_to method takes two arguments as per documentation

The second argument is the key :notice .

However, in your case, 2 ruby ​​cannot determine if there is one or more hashes. Only one hash is considered passed to the redirect_to method.

You can force ruby ​​to pass a second hash by explicitly placing brackets around each hash:

 format.html { redirect_to({:action => "show_matches", :id => @trial.id}, {:notice => "Candidate was successfully registered."}) } 

Case 3 works because there is no ambiguous hash situation.