Ruby 自学记录 8

In the other 7 lessons,I know the Ruby on Rails how to work using MVC pattern.
https://guides.rubyonrails.org/getting_started.html
In java,the generate model already have same tools to make it, like [MyBatis Generator].It will generate three layers in the project too.
And reading the Ruby stuff book,the exception will catch using :

begin
      //expression code
rescue
      puts "somethings wrong about that code"
end

Now,I wll update the "Article demo" with document.

https://guides.rubyonrails.org/getting_started.html#adding-some-validation

---

articles_controller.rb

class ArticlesController < ApplicationController
  # define a action the new page to create a new article [form]
  def new
    @article = Article.new
  end

  # index page will show all the articles
  def index
    @articles = Article.all
  end

    # after the article submit redirect to this show page
  def show
    @article = Article.find(params[:id])
  end

  # action create
  def create
    # render show the parameters
    # render plain: params[:article].inspect

    # we need to change the create action to use
    #
    ## params[:article] contains the attributes we're interested in
    @article = Article.new(article_params)
    ## saving the model in the database .save will return boolean
    # if the save saved redirectTo article page
    if @article.save
      redirect_to @article
    else
      # else render page new
      render 'new'
    end
  end

  private
  def article_params
    params.require(:article).permit(:title,:text)
  end
end

index.html.erb

<h1>Listing Articles</h1>

<h1>Hello, Rails!</h1>
<%= link_to 'My Blog', "https://www.cnblogs.com/ukzq" ,:target=>"_blank" %>
<br>
<%= link_to 'Create New Article', new_article_url %>

<table>
  <tr>
    <th>Title</th>
    <th>Text</th>
    <th></th>
  </tr>

  <% @articles.each do |article| %>
    <tr>
      <td><%= article.title %></td>
      <td><%= article.text %></td>
      <td><%= link_to 'Show', article_path(article) %></td>
    </tr>
  <% end %>
</table>

I'll come again when I'm full
to be continued

This time we point the form to the update action,which is not defined yet but will be very soon.


Finally, we want to show a link to the edit action in the list of all the articles,
so let's add that now to index.html.erb to make it appear next to the "Show" link:

<table>
  <tr>
    <th>Title</th>
    <th>Text</th>
    <th></th>
  </tr>

  <% @articles.each do |article| %>
    <tr>
      <td><%= article.title %></td>
      <td><%= article.text %></td>
      <td><%= link_to 'Show', article_path(article) %></td>
      <td><%= link_to 'Edit', edit_article_path(article) %></td>
    </tr>
  <% end %>
</table>

define a action in controller too:

  def edit
    @article = Article.find(params[:id])
  end

Now, looks like that ↑.