Question

大家好我有关于params [：value]的问题。

我的模型必须由名为value的变量属性组成，我可以在控制器中使用此params [：value]吗？

我正在尝试从我的VIEW获取数据，但变量值仅用于1个函数。所以我在想是否有另一种方法可以做。

在我看来[这个问题与第二个radio_button =指定的ATGC数量有关]：

<%= form_for (@generator ) do |f| %>
  <% if @generator.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@generator.errors.count, "error") %> prohibited this generator from being saved:</h2>

      <ul>
      <% @generator.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <label>Primer Length</label><br>
       <%= f.number_field :primer_length , min: 3 %>
  </div>

    <label>Selection :</label><br>
<table>
    <thead>
      <tr>
        <th><label>Randomly</label>
        <%= radio_button_tag(:choice, 'Randomly', true )%></th>

        <th><label>Number of ATGC specified</label>
        <%= radio_button_tag(:choice,'No_of_ATGC')%> </th>
     </tr>
    </thead>

    <tbody>
        <tr>
            <td></td>
            <td><label>Number of A :</label>
            <%= number_field_tag 'No_of_A'%><br>
            <label>Number of T :</label>
            <%= number_field_tag 'No_of_T'%><br>
            <label>Number of G :</label>
            <%= number_field_tag 'No_of_G'%><br>
            <label>Number of C :</label>
            <%= number_field_tag 'No_of_C'%><br></td>
        </tr>
    </tbody>
</table>    

<%= button_to('Generate',generate_option_generator_path(@generator))%>
<% end %>

在GeneratorController中

class GeneratorsController < ApplicationController
  before_action :set_generator, only: [:show, :edit, :update, :destroy]
  after_action :generate_option, only: [:create, :update]
  # GET /generators
  # GET /generators.json
  def index
    @generators = Generator.all
  end

  # GET /generators/1
  # GET /generators/1.json
  def show
  end

  # GET /generators/new
  def new
    @generator = Generator.new
  end

  # GET /generators/1/edit
  def edit
  end

  # POST /generators
  # POST /generators.json
  def create    
    @generator = Generator.new(generator_params)

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

  # PATCH/PUT /generators/1
  # PATCH/PUT /generators/1.json
  def update
    respond_to do |format|
      if @generator.update(generator_params)
        format.html { redirect_to @generator, notice: 'Generator was successfully updated.' }
        format.json { head :no_content }
        #random_generate
        #@generator.save!
      else
        format.html { render action: 'edit' }
        format.json { render json: @generator.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /generators/1
  # DELETE /generators/1.json
  def destroy
    @generator.destroy
    respond_to do |format|
      format.html { redirect_to generators_url }
      format.json { head :no_content }
    end
  end

  def generate_option
    @generator.choice = params[:choice]
    if params[:choice] == 'Randomly'
        random_generate
    elsif params[:choice] == 'No_of_ATGC'

    end
    @generator.save!
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_generator
      @generator = Generator.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def generator_params
      params.require(:generator).permit(:primer_length, :choice, :random_primer_generated)
    end
end

在ApplicationController中：

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception 
  def random_generate
     length = @generator.primer_length
        chars = 'ATGC'
        seq = ''
        length.times { seq << chars[rand(chars.size)] }
       @generator.random_primer_generated = seq
  end

  def no_ATGC

    counts = {'a'=>no_of_a,'t'=>no_of_a,'g'=>no_of_a,'c'=>no_of_a}
    @generator.random_primer_generated = Bio::Sequence::NA.randomize(counts)

  end

end

基本上这就是我需要做的。我需要知道A的T的G和C有多少才能为用户生成一些东西。此外，我不确定宝石Bioruby是否可以在Rails中访问〜我不必担心RUby，但Rails架构很难。我在我的gemfile中定义了宝石Bioruby。希望它有效。

Answer 1

params包含从提交的表单中收到的信息。所以，这实际上取决于你是否在表单中有一个名称为“value”的字段（编辑框，选择框等）。因为，大多数Rails表单都是从Model生成的，通常意味着你的模型中有一个属性“value”。

Answer 2

如果您尝试使用参数创建/更新模型项，则会关注模型。您可以将任何内容作为参数传递给控制器，但如果您创建/更新模型项，则参数必须位于模型中。

params [：value]是模型变量还是本地变量

2 个答案: