RoR - Restful Actions

Index:

用于检索所有条目

# index.json.jbuilder 

json.array!(@post) do |post|
    json.extract! post, :id, :title, :content
    json.url post_url(post, format: :json)
end

#/posts.json

Show&Destory:

1.根据id检索相应的条目

2.跳转到show.html.erb 提供相应

#example

localhost:3000/posts/1

#show.json.jbuilder 

json.extract! @post, :id, :title, :content, :created_at, :updated_at

localhost:3000/posts/2.json 

respond_to:  特定怎么去相应一个request

redirect_to:

# DELETE /posts/1
# DELETE /posts/1.json    

def destory
    @post.destory
    respond_to do |format|
        format.html {redirect_ to posts_url, notice: 'Post deleted' }
        format.json {head :no_content }
    end
end 

New&Create:

# GET /posts/new

def new
    @post = Post.new
end 

# Look for new.html.erb

Create Action 没有模板，它会试着将object存进数据库，如果成功的话重定向到show 模板

如果没有成功render new action

Flash:

# flash 

flash[:attribute] = value 

# :notice (good)  :alert (bad)
  

edit:

# GET /posts/1/edit 

before_action :set_post, only: [:show, :edit, :update, :destory]

def edit 

end 

private
    def set_post
        @psot = Post.find(params[:id])
    end
end 

update:

用id检索到需要update的object

用edit form里面的parameters去更新object

保存更新的数据到数据库

（默认）成功的话，重定向到show 模板

不成功，到edit

before_action :set_post, only: [:show, :edit, :update, :destory]

# PATCH/PUT /posts/1
# PATCH/PUT /posts/1.json

def update
    respond_to do |format|
            if @post.update(post_params)
                format.html {redirect_to @post, notice: 'Post was updated.' }
                format.json { render :show, status: :ok, location: @post }
            else
                format.html { render :edit }
                format.json {  render json: @post.errors, status: :unprocessable_entity}
            end
    end
end 

private
    def set_post
        @psot = Post.find(params[:id])
    end

    def post_params
        params.require(:post).permit(:title, :content)
    end
end 

Partials:

# partial start with _

<%= render @posts %> 

is equivalent to 

<% @posts.each do |post| %>
    <%= render post %>
<% end %>

Form Helpers and Layouts:

<%= form_for(@post) do |f| %>
    <% if @post.errors.any? %>
    <% end %>

    <div class="field">
        <%= f.label :title %> <br>
        <%= t.text_field :title %>
    </div>

    <div class="field">
        <%= f.label :content %> <br>
        <%= f.text_area :content %>
    </div>

    <div class= "actions">
        <%= f.submit %>
    </div>
<% end %>

如果想在controller里用model里的method，

首先defind self.method 在model里

接着用model.method 在controller里面