Protocol :: TrasmissionMeansController中的ActionController :: ParameterMissing＃create

Question

我對此代碼有問題。

這是控制器：

def create 
    @mean = TrasmissionMean.new(trasmission_mean_params) 
    if @mean.save 
    flash[:success] = "Mezzo di Trasmissione #{@mean.description}" 
    else 
    flash[:error] = "Error #{@mean.errors.full_messages}" 
    render :action => 'new' 
    end 
end 

def trasmission_mean_params 
    params.require(:mean).permit(:description) 
end 

我有一個問題與此代碼。

這是視圖，呈現形式：

<div class="row"> 
    <div class="col-md-10 col-md-offset-1"> 
    <%= form_for @mean, :html => {:class => "form-horizontal" },:url => url_for(:controller => "trasmission_means", :action => "create") do |f| %> 
     <hr> 
     <%= render partial: "form", :locals => { :@mean => @mean, :f => f } %> 
     <hr> 
     <%= f.submit "Aggiungi", class: 'btn btn-success btn-lg pull-right' %> 
    <% end %> 
    </div> 
</div> 

呈現形式：

<div class="form-group"> 
    <div class="col-lg-12"> 
    <%= f.text_area :description, :rows => 4, class: 'form-control ', placeholder: 'Descrizione' %> 
    </div> 
</div> 

，這是錯誤。我不明白問題出在哪裏

ActionController::ParameterMissing in Protocol::TrasmissionMeansController#create 參數是丟失或爲空值：是指

Answer 1

的參數是基於類

def trasmission_mean_params 
    params.require(:mean).permit(:description) 
end 

是params哈希表尋找均值但你的類被稱爲TransmissionMean這意味着它應該是

def trasmission_mean_params 
    params.require(:transmission_mean).permit(:description) 
end