CODEWITHSUNDEEP
ruby-on-railsruby
yamaoka
yamaoka

Reputation: 131

Can someone explain to me what this code is doing?

I am currently building an online course and I was having trouble accessing a lesson that is associated with a certain course.

A developer friend of mine solved the problem for me but I'm not really sure why this code works and if there are different ways, more of a Rails conventional way to write this code.

<% @courses.each do |course| %>
    <tr>
      <td><%= link_to course.title, "courses/#{course.id}" %></td>
    </tr>
  <% end %>

I am not sure what this part "courses/#{course.id}" is doing. Is there a way to write this using a more conventional seeming names route helper?

Upvotes: 1

Views: 82

Answers (3)

mantralux
mantralux

Reputation: 33

For some reason your friend did this:

<td><%= link_to course.title, "courses/#{course.id}" %></td>

...instead of this:

<td><%= link_to course.title, course %></td>

...and I have no idea why. The second example is how you use links in Rails. The first example doesn't safeguard you against possible future URL changes.

Upvotes: 0

Miron Marczuk
Miron Marczuk

Reputation: 81

As Ursus answer explains, courses/#{course.id} creates URL directing to specific course path by using string interpolation. For example, if @courses variable is an array with Course objects with ids: [1, 2, 3], then you will receive links directing to "course/1", "course/2", course/3".

To replace that interpolation, you can simply write 

<%= link_to course.title, course %>

It will create the same output as "courses/#{course.id}"

To learn more about string intepolation, you can start here: http://ruby-for-beginners.rubymonstas.org/bonus/string_interpolation.html

Upvotes: 0

Ursus
Ursus

Reputation: 30071

It should be the same as course_path(course)

This call just figure out the path for you. The expression in your code simply build this path putting together "courses/" and the id of the course (but using interpolation, not concatenation).

Upvotes: 4

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