Redirect and render in Ruby on Rails - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does redirect_to do in Rails?

redirect_to sends the browser to a different URL, causing a new request. It does not render a view directly.

beginner

What is the difference between render and redirect_to in Rails?

render shows a view template without changing the URL or making a new request.<br>redirect_to sends a new request to a different URL, changing the browser's address.

intermediate

Can you use render and redirect_to together in the same controller action?

No, you should use only one. render displays a view, while redirect_to sends a new request. Using both causes errors.

intermediate

What happens if you call redirect_to after render in a Rails action?

Rails raises a DoubleRenderError because you can only send one response per request.

beginner

How do you redirect to a named route in Rails?

Use redirect_to with the route helper, like redirect_to posts_path to go to the posts index page.

What does render :edit do in a Rails controller?

A Redirects the browser to the edit URL

B Displays the edit view without changing the URL

C Reloads the current page

D Sends a JSON response

render :edit shows the edit template without a new request or URL change.

Which method causes the browser to make a new request to a different URL?

A redirect_to

B render

C flash

D params

redirect_to sends a new HTTP request to the specified URL.

What error occurs if you call both render and redirect_to in one action?

A NoMethodError

B ArgumentError

C SyntaxError

D DoubleRenderError

Rails raises DoubleRenderError because only one response is allowed per request.

How do you redirect to the root path in Rails?

A redirect_to root_path

B render root_path

C redirect root_path

D render_to root_path

Use redirect_to root_path to send the browser to the home page.

Which of these is true about render?

A It changes the browser URL

B It sends a new HTTP request

C It displays a view template without a new request

D It redirects to another controller

render shows a view template in the current request without changing the URL.

Explain in your own words the difference between redirect_to and render in Rails controllers.

Think about what the browser does after each method is called.

Describe what happens if you try to use both render and redirect_to in the same Rails action.

Rails does not allow sending two responses for one request.