Rails 7

One of the best places to see help for Ruby programming language is the Ruby mailing list. Visit https://www.ruby-lang.org/en/community/mailing-lists/, scroll down to see a form like this:

Fill in your email and submit it to join the mailing list.

Ruby on Rails has a discussion forum, one can find it here https://discuss.rubyonrails.org/, register and try to answer people who have doubts, and ask questions about Rails here.

If you are a programmer, you would have heard about stack overflow https://stackoerflow.com, you can ask your doubts there too. Personally I would prefer Ruby mailing list and Ruby on Rails forum.

Reddit has a passionate Ruby community https://www.reddit.com/r/ruby/ and Rails community https://www.reddit.com/r/rails/, you can discuss and ask doubts here too.

You might get doubt, or find a way to do something short using Ruby or Rails, both Ruby language and Rails framework has got a rich set of API. One can find Ruby API here https://ruby-doc.org/ and Rails api here https://api.rubyonrails.org/. These links will be useful when you are well acquainted with Ruby and Rails.

One should know to write code if you want to start to learn Rails. Don’t think that by not even knowing how to write code, and not having prior experience of writing code, you can somehow get started with Rails. It does not work.

You must have knowledge of GNU/Linux, have a good GNU/Linux system, and try to learn about it. You can learn GNU/Linux from this excellent website https://linuxjourney.com

You need to know how to create web pages to start learning Rails. You need to know about HTML and CSS, one can learn about HTML here https://www.w3schools.com/html/ and CSS here https://www.w3schools.com/CSS/

JavaScript is the only practical language that works on browser now. There is another thing called web assembly, but for today it’s just a curiosity. You can learn JavaScript here https://www.w3schools.com/js/, or get this book JavaScript: The Definitive Guide here https://www.amazon.in/dp/B088P9Q6BB/

Rails is used to create webpages with Database (DB) backend. For that you need to know SQL, you may learn it here https://www.w3schools.com/sql/

I would also one to install PostgreSQL https://www.w3schools.com/sql/ on ones system and practice it.

Finally, Ruby programming language is the hero of Ruby on Rails. Rails is built using this language. I would recommend my book I Love Ruby https://i-love-ruby.gitlab.io/ to learn it.

Today almost no one codes in isolation, you need to work with some one, you may make a big mistake in your code which need to be reversed. git is tool initially created by Linus Tovarlds, the same guy who created GNU/Linux, and its the version control tool for programmers. You can learn git here https://www.tutorialspoint.com/git/index.htm

step_0

When you execute the above command, you will see a lot of output generated as shown below, never mind them.

Once that’s done, cd into hello_rails you can run rails s or rails server in the terminal and open https://localhost:3000 in terminal and you will get the Rails first screen as shown below.

Press Ctrl+C to exit Rails in terminal.

Let’s create something called static pages, that is these are web pages who’s content does not change with time. for that type this in the terminal.

You should be getting an output like the one shown below.

Now start the rails server by punching rails s in terminal, and visit http://localhost:3000/welcome/hello and you will be getting a screen like this one.

When you visit the url http://localhost:3000/welcome/wish, you will be getting a display as shown below in the browser.

step_2

Now let’s change our view files and link then so that we have some form of navigation. Open app app/views/welcome/hello.html.erb, and change it as shown:

Notice the <%= link_to "Wish Me", {action: :wish} %>, the file name is hello.html.erb, here the .html says it will be rendered as HTML, but the .erb means Embedded Ruby. So we can put a valid Ruby between <%= and %>, and it will be embedded in the web page.

We put the following thing link_to "Wish Me", {action: :wish} in it, this is nothing but link_to method that’s defined in the rails gem, you can get its documentation here https://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-link_to.

The first argument we pass to link to the text that must appear in the web page here its "Wish Me", the second argument should be the URL, so here we tell it to navigate to action wish by passing this hash {action: :wish} , we embed the code in HTML using this ERB syntax: <%= link_to "Wish Me", {action: :wish} %>. This generates a web page as shown:

Similarly in app/views/welcome/wish.html.erb, let’s put the following content into it:

Here <%= link_to "Go Back", {action: :hello} %> generates a hyperlink with text Go Bak, and it will be linked to action hello.

Fire up your rails server in terminal by typing rails s, when you hit the URL http://localhost:3000/welcome/hello, you will see a page as shown:

When you click Wish Me, you will be taken to a page that displays the content in wish me as shown below:

You could click Go Back to go to your hello page once again.

step_3

In the last section we have seen how to add static pages to Rails applications. Static pages are web pages that do not change with time, but what if we want to show pages who content is dynamic? We will see that here.

To do that open routes.rb and add this get 'welcome/time' as shown below:

We tell Rails to respond to another route which is http://localhost:3000/welcome/time, when user hits that URL from his browser we will show him tthe time.

Now let’s add an action called time in WelcomeController as shown.

Once added app/controllers/welcome_controller.rb should look as shown above.

Now create a file called app/views/welcome/time.html.erb as shown below

Note these lines:

In the above piece of code note <%= Time.now %>, we are getting an instance of Time using Time.now and embedding into the web page by placing it between <%= and %>.

Now visit http://localhost:3000/welcome/time, you should be getting output similar to the image shown below:

Refresh the page, the time should have changed. We created a dynamic page using Rails.

step_4

It’s okay to have some code in view, but views should be more of pure views as much as possible, it’s better to move any code in view to corresponding action in the controller. So delete <%= Time.now %> in app/views/welcome/time.html.erb and replace it with <%= @time %>

As you see @time is an instance variable, and where do we define it? We define it in action time in WelcomeController as shown below:

Once done, refresh the page, the functionality would be the same.

But do remember that you have made the code bit better.

step_5

When you visit http://localhost:3000/welcome/home, you get a link to navigate to wish page and when you visit wish page, you get a link to go back to home. Now we have added a page to show time too, we have increased complexity of our app. It would be great if we have a common navigation in all pages where we can jump to any other page.

So in app/views/welcome/, create a file called _nav.html.erb, and fill it with content as shown below:

So in the code above we have put three link_to which point to all three actions. The file has an underscore at the beginning to denote that it’s a partial. That is this not a a full view code, but it’s a piece code that can be reused in other places.

Now let’s embed this _nav.html.erb in hello.html.erb as shown:

Notice the <%= render 'nav' %> which looks for _nav.html.erb in app/views/welcome/ and embeds its content between the <p> and </p> tags.

Similarly let’s embed _nav.html.erb in time.html.erb

and in wish.html.erb as shown:

Now when you visit http://localhost:3000/welcome/hello, you will see a screen with navigation links as shown:

These links appear in http://localhost:3000/welcome/wish

and in http://localhost:3000/welcome/time as shown:

Happy hoppin pages!

step_6

When you type https://localhost:3000 in your browser, you get default Rails 7 page as shown:

Won’t it be great if it directly routs to welcome/hello when we type https://localhost:3000 in browser?

To do that add root "welcome#hello" in routes.rb as shown below:

Now type https://localhost:3000 or refresh the browser and you will get hello page displayed as shown: