We're back on the rails log again.

Rails controllers insert load of model data into a view

to create a response for the browser.

The view is responsible for displaying data to your users.

Views usually though not always take the form of HTML templates with Ruby

expressions embedded in them.

Those expressions refer to data loaded from the model

to populate an HTML page with data.

This line in our controller renders the view.

And remember,

even if we remove this line again the same thing would happen by default.

This layout application parameter here instructs

Rails to load App > Views > Layouts > application.html.erb.

This is an ERB template.

ERB stands for embedded ruby.

It's a plain text file with ruby code embedded inside it.

Between the opening HTML tag and

the closing HTML tag is an HTML document which gets rendered as a web page.

The head tag contains information about the entire document.

Like the title that the browser should display.

And here is the most important part of the layout.

Within the body HTML tag is an ERB tag with the yield keyword.

This will render another template and insert the result into this layout.

Rails creates files from view templates in the app > views sub directory.

Since this is a view for post resources, it will be within the posts sub directory.

And since this is a view for the index controller action,

it will be in the index.html.erb file.

The template has a bunch of HTML tags that'll be inserted

verbatim into the HTML page.

ERB tags began with angle bracket percent sign and

contain ruby code that gets interpreted.

The result gets inserted into the HTML.

Remember the back in the controller we assigned a collection of

post objects to be post instance variable.

The call to post.each processes

each of those posts adding a table row with the post title to the output HTML

you can see the resulting HTML if we open our browsers developer tools.

You'll be working with HTML templates a lot in Rails.

If you don't have a firm understanding of HTML yet

I'd recommend checking the teachers notes to learn more.

So when a browser requests a page Rails receives the request,

routes it to the appropriate controller class and action method.

The controller retrieve some model data and

then the controller embeds the model data within a view.

The results of rendering that view then gets returned to the browser

as a response.

Now you have an overview of how Rails handles a request from beginning to end.

Over the remainder of this course we'll look at the components Rails uses

in more detail.

We'll start with models, and that's up next.