Ruby on Rails Quick Learning Practice Guide chapter3

3-1-4 Use properly for each database environment

There are three types of environments in the database. A database is also allocated according to each task.

Environment type	Environmental system name	Use
Development environment	development	Check the operation during development
testing environment	test	Perform automated testing
Production environment	production	Make it available to users

At the time of development, we will use the development environment and the test environment. These two files are automatically created when you execute db: create.

3-1-5 Make it possible to use slim to write the view layer efficiently (how to use slim)

By default, if you change the template engine used in erb to a template engine called slim, you can easily write code.

How to write slim

How to write erb	How to write slim
<% name %>	- name
<%= name %>	= name
#comment	/comment
Hello </p＞	p Hello
＜a href='//example.com"＞image＜/a＞	a href="//example.com"image
＜div class="profile name"＞	.profile.name
＜div id="pam"＞	#pam

Slim is convenient when you get used to it, so it will be difficult until you get used to it.

3-2-2 Create a template for the task model

・ Create a model To create a model, enter what you want to create after rails g (this time model)

$ rails g model Task name:string description:text

By doing this ・ Task model can be created -Create a blueprint migration file that can create a table with name: string description: text -Create a file for automatic model testing

To create a table, db: migrate the migration file to create the table.

3-3 Controller and view

·routing Routing looks at the URL and HTTP method and assigns it to each action of the controller.

URL example	HTTP method	Action name	Function name	role
/tasks	GET	index	List display	Show all tasks
/tasks/17	GET	show	Detail View	Show tasks with a specific id
/tasks/new	GET	new	New registration screen	New registration screenを表示する
/tasks	POST	create	Registration	Registration処理を行う
/tasks/17/edit	GET	edit	Editing screen	Editing screenを表示する
/tasks/17	PATCH,PUT	update	update	update処理を行う
/tasks/17	DELETE	destory	Delete	Delete処理を行う

HTTP methods are important! !!

・ How to combine routing into one

get 'tasks/index'
get 'tasks/show'
get 'tasks/new'
get 'tasks/edit'

Summarize the above routing using resources

resource :tasks

The resources method can combine the seven actions of index, show, new, create, edit, update and destroy into one.

get "/" => "tasks#index"

root to: 'tasks#index'

Also, if you specify the initial screen of rails as root to, the view linked to that action will be the initial screen.

・ URL helper method You can also replace / tasks / new, / tasks / edit, etc. with helper methods

URL example	HTTP method	URL pattern name	URL helper method
/tasks	GET	tasks	tasks_path
/tasks/17	GET	task	task_path
/tasks/new	GET	new_task	new_task_path
/tasks	POST	tasks	tasks_path
/tasks/17/edit	GET	edit_task	edit_task_path
/tasks/17	PATCH、PUT	task	task_path
/tasks/17	DELETE	task	task_path

3-3-1-5 Implement the view of the new registration screen

New registration screen

`ruby:app/views/tasks/new.html.slim`


New registration of h1 task

.nav.justify-content-end
  = link_to 'List', tasks_path, class: 'nav-link'

=form_with model:@task,local:true do |f|
  .form-group
    =f.label :name 
    =f.text_field :name, class: 'form-control', id: 'task_name'

  .form-group
    =f.label :name 
    =f.text_area :description, rows: 5, class: 'form-control', id: 'task_description'
  =f.submit nil, class: 'btn btn-primary'

form_with is for creating a form. Fill out the required form using f. ・ Explanation .nav.justify-content-end: Code provided by Bootstrap f.label: name: Display the label corresponding to the input field Originally name, but since it has been translated into Japanese, it will be named name = f.text_field: name: Where to put the text class:'form-control: The class originally attached to bootstrap

3-3-1-6 Implement the registration action

`app/controllers/tasks_controller.rb`


def create
   task = Task.new(task_params)
   task.save!
   redirect_to tasks_url, notice: "task"#{task.name}Was registered"
end



private

def task_params
   params.require(:task).permit(:name,:description)
end

require (: task) .permit (: name,: description) means "create a new task by allowing only the name and description information". Get the created parameter with params.

3-3-3 Implement the detailed display function

tasks / [task id] can be expressed as task_path (task) using the URL helper method. The id is automatically determined from the argument task in rails.

3-3-3-2 Display task attribute information on the detail screen

simple_format(h(@task.description),{},sanitize: false, wrapper_tag: "div")

Sentences that include explanations, such as description, become long and require line breaks. Line breaks are easily performed by using simple_format.

Rails learning day 1 part 3