HowToNewARailsProject.md

#How to new a rails project

1. mkdir rails_project

2. cd rails_project

3. rails new job_board -T

4. 如果有改過Gemfile, 都要bundle install

5. rail s啟動rails server

   • 啟動後可以到http://localhost:3000/rails/info查看routes資訊

6. 編輯route.rb i. REST類型懶人route-> resoueces :jobs i. 普通route-> rails g controller pages i. GET route-> get 'welcome/index' i. 終端機輸入rails generate controller job
   產生：
   > controllers/jobs_controller.erb
   views/jobs
   helpers/jobs_helper.erb
   assets/javascripts/jobs.js.coffee
   assets/stylesheets/jobs.css.scss

    1. controller加上  
    	```
    		def index
    		end
    	```
    2. view新增index.html.erb
    3. 就能到<http://localhost:3000/jobs>看首頁了
   

7. 新增資料庫 i. 終端機輸入rails g model job
   會新增 >db/migrate/時間戳記_create_jobs.rb
   models/job.rb i. 編輯 時間戳記_create_jobs.rb
   1. 在create_table :jobs do |t|下輸入你想增加的欄位
   例如t.text :title
   2. 儲存後終端機輸入rake db:migrate讓要新增的欄位寫進資料庫 i. 也可以rails g model group title:string description:string 再rake db:migrate

8. 要怎麼new一個job?

    #new.html.erb
    	<h1>Add a job</h1>
    	<%= form_for @job do |f| %>
    	<div>
    		<%= f.label :title %>
    		<%= f.text_field :title %>
    	</div>
    	<div>
     		<%= f.label :description %>
     		<%= f.text_field :description %>
    	</div>
     	<div>
       		<%= f.submit %>
     	</div>
    	<% end %>
    
    #jobs.controller.rb
    	def new
    		@job = Job.new
    	end
    	
    	def create
    		Job.create(job_params)
    		redirect_to jobs_path
    	end
   
    	private
    	def job_params
    		params.require(:job).permit(:title, :description)
    	end
   

   如果想查詢資料庫裡面有幾的Job
   可以在終端機輸入rails c(Rails console模式),接下來打Job.count系統會算給你
   要離開rails c模式,輸入exit

9. 顯示所有jobs
   controller

    @jobs = Job.all   
   

   view

    <% @jobs.each do |job| %>
    	<h3><%= job.title %></h3>
    	<p><%= job.description %></p>
    <% end %>
   

10. 我的new跟edit頁面差不多,想要DRY,怎麼辦?
    製作partial

    #app/views/jobs/_form.html.erb
    <%= form_for @job do |f| %>
    	<div>
    		<%= f.label :title %>
    		<%= f.text_field :title %>
    	</div>
    	<div>
    		<%= f.label :description %>
    		<%= f.text_area :description, size: '60x6' %>
    	</div>
    	<div>
    		<%= f.submit %>
    	</div>
    	<% end %>
    

    現在可以在new及edit裡面加上<%= render "form" %>引用form這個partial

---

非RESTful的route 新增controller: rails g controller pages

controller輸入

def welcome   
end

view新增welcome.html.erb

route輸入root :to => ""pages#welcome""

注意 controller、view、route都必須同樣命名welcome才能成功印出內容