[RUBY] Task management application creation procedure

1. Preparation for application creation

1-1. Think about the content of the application to be created

1-2. Decide the application name and create a template

rails new application name[option]

#Example)

rails new taskmanage -d postgresql

1-3. Create db

Go to the directory where you created the application and create a db

rails db:create

1-4. Try starting the server

Hit the following command, 「http://localhost:3000」 Go to and see if the rails default page is displayed

rails s

2. Create a model

Model components

--Ruby class corresponding to the model Camel case

--Database table corresponding to the model Snake case with multiple model class names

2-1. Design the attributes of the model

2-2. Create a model template

rails g model [Model name] [Attribute name:Data typeAttribute name:Data type...] [option]

#Example)

rails g model Task name:string description:text

2-3. Migrate and add table to db

Check the created migration file and execute ** rails db: migrate **

3. Create controller and view

rails g controller controller name[Action name Action name...] [option]

#Example)

rails g controller tasks index show new edit

Rails.application.routes.draw do
 root to: 'tasks#index'
 resources :tasks
end

3. Implementation of new registration function

3-1. Added a link to the new registration page on the list screen

= link_to 'sign up', new_task_path

3-2. Implemented actions for new registration screen

tasks_controller.rb

def new
 @task = Task.new
end

3-3. Implemented new registration page view

slim:new.html.slim

= form_with model: @task, local: true do |f|
 .form-group
  = f.label :name #label =Focus the input field by displaying the name of the input field and clicking the label part
  = f.text_field :name
 .form-group
  = f.label :description
  = f.text_area :description
 = f.submit nil

3-4. Implementation of registration action

** create action ** = "Save the data sent from the registration form in the db and move to the list screen"

tasks_controller.rb

def create
 @task= Task.new(task_params)
 task.save
 redirect_to tasks_url, notice:"task"#{task.name}Has been registered."
end
private
 def task_params #Strong parameters = Information sent from the form as request parameters is as expected{task: {...}}The role of checking if it is in the form of and extracting only the necessary information
  params.require(:task).permit(:name, :description)
 end

Difference between render and Redirect_to

flash message

Deliver a bit of data to the next request when redirecting

 redirect_to tasks_url, notice:"task"#{task.name}Has been registered."
#Means to redirect after sending a task registration completion message

flash.now[:alert] = "Alert immediately"
#If in the same request, flash.now

4. Implementation of list display function

4-1. Implemented actions for new registration screen

tasks_controller.rb

def index
 @tasks = Task.all
end

4-2. Display all tasks on the list page

@tasks.each do |task|
 task.name
 task.created_at

5. Implementation of detailed display function

5-1. Added a link from the list page to the detail page

ruby:index.html.slim

link_to task.name, task_path(task)

5-2. Get the selected task with the detail display action

tasks_controller.rb

def show
 @task = Task.find(params[:id])
end

5-3. Get the selected task with the detail view action

ruby:show.html.slim

@task.id
@task.name
@task.created_at
@task.updated_at

6. Implementation of editing function

6-1. Added a link to the edit page on the list page and detail page

ruby:index.html.slim

link_to 'Edit', edit_task_path(task)

ruby:show.html.slim

link_to 'Edit', edit_task_path

6-2. Define edit and update actions

tasks_controller.rb

def edit
 @task = Task.find(params[:id])
end

def update
 task = Task.find(params[:id])
 task.update!(task_params)
 redirect_to tasks_url, notice: "task"#{task.name}"The has been updated."
end

6-3. Implemented edit page view

slim:new.html.slim

= form_with model: @task, local: true do |f|
 .form-group
  = f.label :name #label =Focus the input field by displaying the name of the input field and clicking the label part
  = f.text_field :name
 .form-group
  = f.label :description
  = f.text_area :description
 = f.submit nil

Commonality using partial templates

Use a partial template to put together the common parts of the new registration page and the edit page

ruby:_form.html.slim

= form_with model: task, local: true do |f|
 .form-group
  = f.label :name 
  = f.text_field :name
 .form-group
  = f.label :description
  = f.text_area :description
 = f.submit nil

Partial template call

ruby:new.html.slim

= render partial: 'form'. locals: {task: @task} #"Instance variables@Pass task as a local variable task in a partial "

ruby:edit.html.slim

= render partial: 'form'. locals: {task: @task}

7. Implementation of delete function

7-1. Added a cut button to the list page and detail page

ruby:index.html.slim

= link_to 'Delete', task, method: :delete, date: { confirm: "task"#{task.name}」をDeleteします。よろしいですか？"}

ruby:show.html.slim

= link_to 'Delete', @task, method: :delete, date: { confirm: "task"#{task.name}」をDeleteします。よろしいですか？"}

7-2. Define the destroy action

tasks_controller.rb

def destroy
 task = Task.find(params[:id])
 task.destroy
 redirect_to tasks_url, notice: "task"#{task.name}Was deleted."
end

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