Ruby on Rails执行

Question

I am new to Ruby on Rails. I am trying my best to learn it through the book Agile Web Development Using Rails . I got stuck trying to understand the concepts behind the execution.

I created a new project using rails_apps> rails demo . The book asked me to create a controller called Say (please note the capital "S") and the following happened:

1. there was a folder by the name say (please note the lowercase "s") inside a folder called "views"
2. there was a controller file :say_controller".

I then made a request through http://localhost/say/hello . I am really confused by the fact that, my project name demo is nowhere in the request. What happens if I create another controller in, say, another project and make the same request?

And why is that say has a lowercase s in the request instead of capital S? What's happening behind the curtains here?

Answer 1

When you run the command rails server it is launching a process that is only for the specific application. It sees the request from the browser for that application and serves the appropriate content.

If you made another application, you would not be able to run it on the same port at the same time as the original application. You would need to run rails server -p NEW_PORT where NEW_PORT is different from the already running rails application. Then you would be able to access the application from http://localhost:NEW_PORT

The multiple servers allow you to have the same controllers in different applications, because they are completely separate instances now.

Answer 2

Taking your questions one by one:

The "name" of your app (the parameter you provide to the rails script) is not used anywhere except for the name of the main directory. I find this provides freedom to not be locked in to the chosen name.

Another controller in another project will be completely independent. The two projects will run at different ports (when using the built-in webserver) or on different paths (when using another webserver like Apache.)

Capitalized (and "camel cased") vs. uncapitalized names are important in Rails, and are simply dictated by convention. Here's a post with some examples. http://itsignals.cascadia.com.au/?p=7