email_form_rails | app demoes a email form | Application Framework library

Let’s generate a controller (here: "home") and an action (here: "index") that you want to use to display the email form. You will most certainly want to use a more suitable name for the controller in your app. Test your routing by running the rails server and opening http://localhost:3000/ in your browser. You should see a default index view page. Now let’s add a form for our message model using the simple form gem Now is the time to check out the [documentation of this nice gem](https://github.com/plataformatec/simple_form). Docs say we need to run a simple_form generator first, so let’s do that. We choose that our index view should contain the email form. In the controller action we need to create a new Message object we can pass to our corresponding view. Let’s use our home#index view to render the form to the user. The form should now get rendered on the page. If we submit it however, we run into trouble. The exception displayed tells us that simple_form automatically generates a url to submit the form to (the form action="…​" attribute) that cannot be found. We can fix this by supplying the form builder with a path set up to receive the form data. Let’s say we want to sumbit the form to "/email" via a post request. To have a look at the routes in our app we can run $ rake routes (you might need to restart your server for it to pick up this change). Great. Routing is set up. We now can provide this action path to our form builder. The way we have just set up our routes is matching a post request to "/email" to an action called "send_email_form" inside our home controller. We intend it to be designed to handle our form data and send the email. Let’s add it to our home controller in a way it will display the params object to see if the message is sent correctly. Let’s submit our form again. We should get an exception now showing the params[:message] object containing the values we just submitted. Great! The form is submitting properly. Now let’s add some logic that checks if the user entries are valid. If they are, the email should be sent (let’s leave a todo here for now) and the user should be notified that things went smoothly. If validation failed the form should be rerendered displaying proper error messages that help him fill out the form as expected. Play time! Let’s test the validation behaviour in the browser.