On Dec 6, 2014, at 4:45 PM, Dave Castellano <[email protected]> wrote:
> Hi, > > Can anyone help... I am trying to understand how 2 different routes > like show and update seem to be the same. Both are > /questions/:id(.:format). > > GET /questions(.:format) > questions#index > POST /questions(.:format) > questions#create But the VERB (part in all caps) is different. REST uses these different action verbs to mean something specific, even if the apparent URL is the same. The HTTP specification describes a number of different verbs -- GET, POST, PATCH, PUT, and DELETE (probably more, these are the ones Rails cares about). Browsers, on the other hand, don't natively do anything except GET and POST. Rails-generated forms send along a form variable named _method with the other request types, so that when the Rails router receives them, it can translate an ordinary POST into a PUT or PATCH or DELETE as needed. When you post to the /questions URL, you are creating a new question and persisting it in the database (modulo any errors halting the save and redirect). When you GET from that same URL, you are requesting the index list of all questions. > GET /questions/new(.:format) > questions#new This one is a special snowflake -- it requests a object that does not exist yet, so you get an empty form to fill out and give that object its parameter values. > GET /questions/:id/edit(.:format) > questions#edit > GET /questions/:id(.:format) > questions#show > PATCH /questions/:id(.:format) > questions#update > PUT /questions/:id(.:format) > questions#update > DELETE /questions/:id(.:format) > questions#destroy It gets a little more subtle when you have saved your question. Now there are four different things you can do with the same saved object (show, edit, update, or delete) and two of those use the same URL and multiple verbs to differentiate what happens. GET with the ID (or another identifier) in the URL will show you the object. GET with the ID and /edit in the URL gets you a form populated with the current state of the object, ready to send back to the server for updating. Both PATCH and PUT will allow you to update an existing object with new data. DELETE does what it says. > > When I try to redirect an action to update, it actually goes to the show > method and I can not figure out how to redirect to the update action. You don't ever want to redirect to the update method* -- you should redirect to methods that respond with HTML content, like :index or :show or :new or :edit. The form you would see on an :edit view would know to PATCH or PUT to the /questions/:id path, which would trigger the update method in your controller. Your controller cannot (easily) make a PATCH request to another method in the same or a different controller. > > redirect_to :action => :update, :id => next_question_id ...instead > redirects to action "show". If you can describe what you're trying to do here, maybe someone can suggest a solution that doesn't step outside of the REST conventions. > > Thanks, > > Dave You're welcome, Walter *There's a really serious reason for this. You don't ever want a URL in your site to alter data just because it was requested. > > -- > Posted via http://www.ruby-forum.com/. > > -- > 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/6ba9e125d1f19b3bd58a024249c91399%40ruby-forum.com. > 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: 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/FE358448-DD66-423C-904F-BBC0A1315DCB%40wdstudio.com. For more options, visit https://groups.google.com/d/optout.
