We'll explore the purpose of views in a Sinatra application and will render them as separate files.
- Explain the advantage of storing HTML in a separate file from
app.rb
- Create
index.erb
in the views directory - Update your controller to render appropriate erb files
- Render multiple routes with multiple views
Rendering plain text is a great way to test the behaviors of our routes, but it
doesn't give us any control over how the content is displayed. We'd like to
structure our content using HTML and render that to the browser instead. The
most basic way to do this is to include html tags as a part of the string we're
rendering. If you haven't already, fork, clone, and open this lab. In the "/"
route of our app.rb
file, try the following:
get '/' do
"<h1>Hello World</h1>"
end
Run shotgun
and go to http://localhost:9393. Your
"Hello World" text should now appear as an <h1>
. Nice!
You can imagine that writing HTML this way would get very messy, very quickly. Luckily, most web frameworks include a templating engine that allows us to render HTML content from a different file. We call these files "views." Views represent what the user sees and comprise the "V" in "MVC."
By default, Sinatra uses a templating engine called ERB, or Embedded RuBy. Our
view files will use the extension .erb
and we can write HTML code there just
like in a plain old .html
file. Sinatra is also configured by default to look
for our .erb
files in a directory called views
.
Create a new file called index.erb
inside of the views
directory. Add the
following code into that file.
<!DOCTYPE html>
<html>
<head>
<title>My First View!!</title>
</head>
<body>
<h1>Hello World</h1>
<p>This HTML code is inside of a '.erb' file in the views directory, where it belongs.</p>
</body>
</html>
Now, we just need to update our controller to render the index.erb
file at the
"/" route. The syntax for this is as follows:
get '/' do
erb :index
end
This tells Sinatra to render a file called index.erb
inside of a directory
called views
. Save your files and refresh your preview to see your changes.
Awesome, right?
We can create as many routes and views as we want. Let's create a route called "/info" in our controller.
get '/' do
erb :index
end
get "/info" do
"Testing the info page"
end
With shotgun
running, head to
http://localhost:9393/info . You should see
"Testing the info page" rendered there. This lets us know that our route is
defined properly. Next, let's have this route render a separate file instead.
Inside of the views
directory, create a file called info.erb
. Add the
following code into that file, and whatever else you like.
<!DOCTYPE html>
<html>
<head>
<title>Info Page</title>
</head>
<body>
<h1>Info Page</h1>
<p>This is the info page: here's some information about me!</p>
</body>
</html>
Finally, update our controller to render that file.
get '/' do
erb :index
end
get "/info" do
erb :info
end
It's important to note that the name of the file doesn't have to match the name
of the route. For example, if we wanted our "/info" route to render a file
called dogs.erb
, we could do so like this:
get '/' do
erb :index
end
get "/info" do
erb :dogs
end
By convention though, we keep our routes and our erb files named the same. This makes it easier to keep track as our projects get bigger.