如何从Ruby on Rails解析JSON数据或（JSON代码）

Question

I have an Ruby on rails source,code now i want to parse the data, and send the data.In my code,it will fetches the name from user and display it,How to parse the data in ROR.

This is my controller.rb code

def index
    @hotels = Hotel.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @hotels }
    end
  end

  # GET /hotels/1
  # GET /hotels/1.json
  def show
    @hotel = Hotel.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @hotel }
    end
  end

  # GET /hotels/new
  # GET /hotels/new.json
  def new
    @hotel = Hotel.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @hotel }
    end
  end

  # GET /hotels/1/edit
  def edit
    @hotel = Hotel.find(params[:id])
  end

  # POST /hotels
  # POST /hotels.json
  def create
    @hotel = Hotel.new(params[:hotel])

    respond_to do |format|
      if @hotel.save
        format.html { redirect_to @hotel, notice: 'Hotel was successfully created.' }
        format.json { render json: @hotel, status: :created, location: @hotel }
      else
        format.html { render action: "new" }
        format.json { render json: @hotel.errors, status: :unprocessable_entity }
      end
    end
  end

  # PUT /hotels/1
  # PUT /hotels/1.json
  def update
    @hotel = Hotel.find(params[:id])

    respond_to do |format|
      if @hotel.update_attributes(params[:hotel])
        format.html { redirect_to @hotel, notice: 'Hotel was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @hotel.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /hotels/1
  # DELETE /hotels/1.json
  def destroy
    @hotel = Hotel.find(params[:id])
    @hotel.destroy

    respond_to do |format|
      format.html { redirect_to hotels_url }
      format.json { head :no_content }
    end
  end

How to parse these data in ROR using Json HOw to write parsing json file for these data,how to do that one

Answer 1

    **Answer of my question**

This part we have to do in controller hotelscontroller.erb

  respond_to :json, :xml
      def index
        @hotels = Hotel.all

        respond_to do |format|
          format.html # show.html.erb
          format.json { render json: @hotels.to_json(:only => [ :id, :name ]) }
        end
      end

view/index.json.erb

[
  <% @hotels.each do |hotel| %>
    { 'id': <%= hotel.id %>, 'name': "<%= hotel.name %>" },
  <% end %>
]

routes.rb

get 'hotels' => 'hotels#index', :as => 'hotels'

Answer 2

You can covert a hash to json by to_json method. For reference please see http://apidock.com/rails/ActiveRecord/Serialization/to_json

for example, if you want to write all hotels to external file.

file = File.open("hotels.txt", "w")
file.puts Hotel.all.to_json
file.close

this will write all hotels in external file hotels.txt

Answer 3

There are many ways:

1. Create method to_json for each model

2. Create view named, ie hotels/index.json.erb and write JSON code using ERb templating engine

    [ <% @hotels.each do |hotel| %> { 'id': <%= hotel.id %>, 'name': "<%= hotel.name %>" }, <% end %> ] 

3. Use library like jbuilder (on the bottom of page is list of alternatives to JBuilder)

    # hotels/index.json.jbuilder json.array!(@hotels) do |hotel| json.id hotel.id json.name hotel.name end