Populating the View8:57 with Jay McGavren
We've set up our controller's "index" method to load all "Page" objects into the "@pages" instance variable. We've also created some "Page" records for it to load. That was only part of the problem, though; we still don't see any page data. That's because we haven't set up the our view template to display the pages we've loaded. To do that, we're going to use ERB to embed some Ruby code into our HTML.
Most text in an ERB template is copied to the output verbatim.
<p>I'll appear in the output exactly as I do here.</p>
But Ruby code within ERB tags gets evaluated instead of being copied directly to the output.
Code within output ERB tags (
<%= %>) is evaluated, and the result is embedded into the output. This code will output the current time:
<p>The current time is: <%= Time.now %></p>
Code within regular ERB tags (
<% %>, without an equals sign) is also evaluated, but is not included directly in the output. It can be used to influence the result of output tags.
If you place a conditional within regular tags, text within the conditional will only be output if the condition is true. This code will include
You passed! in the output:
<% grade = 97 %> <% if grade > 60 %> You passed! <% end %>
This code will not:
<% grade = 54 %> <% if grade > 60 %> You passed! <% end %>
If you place a loop in regular ERB tags, text within the loop will be output repeatedly. This code will output 4
<p> elements with the text
2 fish, and
<% 4.times do |index| %> <p><%= index %> fish</p> <% end %>
@pages contains a collection of
Page objects, this code will output the title of each
<% @pages.each do |page| %> <p> <%= page.title %> </p> <% end %>
Want to learn about looping over the values in a collection with
each? Check out our Ruby Loops course.
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