Question

我对ROR很新，我偶然发现了一个问题。我认为这是一个新手问题，但我不确定是不是。我建立这个应用程序是用户应该能够输入他们的业务中的纸张使用量，并从那里应用程序计算他们的生态足迹，所以说。

在登录时，用户输入他们的员工编号。工作人员编号用于分隔paper_weight等（参见视图示例）。

我知道它基本上按现在的方式工作，但我知道这不是最好的做法。

我还想将包含运行总计的div移动到application.html.erb，但我不能这样做，因为我的计算是在View中而不是在Model中。

这是指向github repo https://github.com/DadiHall/SprettaEMS1.5

的链接

还有其他方法吗？有人可以告诉我吗？

我的index.html.erb视图

<div class="row">
<div class="col-md-10  ">

    <h1>Pappírsnotkun</h1>
    <table class=" well table table-hover">

        <thead>
            <tr>
                <th>Dags</th>
                <th>Tegund</th>
                <th>Þyngd</th>
                <th>Kostnaður</th>
                <th>Þar af umhvm. pappír</th>
                <th>Pappírs magn m.v. Stöðugildi</th>
                <th>Hl.f. Umhvm. Pappírs</th>
                <th>Fjöldi trjáa m.v. magn pappírs</th>
            </tr>
        </thead>

            <tbody>     
                    <% paper_total_cost = 0 %>
                    <% paper_total_trees = 0 %>
                    <% paper_total_staff_ratio = 0 %>   
                <% @papers.each do |paper| %>
                    <tr>
                        <td><%= paper.date.strftime("%Y/%m/%d") %></td>
                        <td><%= paper.paper_type %></td>
                        <td><%= paper.paper_weight %> -kg.</td>
                        <td><%= paper.paper_cost %> -kr.</td>
                        <td><%= paper.env_paper_weight %> -kg.</td>
                        <td><%= (paper.paper_weight.to_i / current_user.staff) %> kg/stöðugildi </td>
                        <td><%= (( paper.env_paper_weight / paper.paper_weight)* 100) %>%</td>  
                        <td><%= (( paper.paper_weight.to_f/1000)*15) %></td>

                        <td><%= link_to 'Sýna', paper, class: 'btn btn-xs btn-info' %></td>
                        <td><%= link_to 'Uppfæra', edit_paper_path(paper), class: 'btn btn-xs btn-warning' %></td>
                        <td><%= link_to 'Eyða', paper, method: :delete, class: 'btn btn-xs btn-danger', data: { confirm: 'Are you sure?' } %></td>
                         <% paper_total_cost = paper_total_cost + (paper.paper_cost.to_i) %>
                         <% paper_total_trees = paper_total_trees + (( paper.paper_weight.to_f/1000)*15) %>
                         <% paper_total_staff_ratio = paper_total_staff_ratio + (paper.paper_weight.to_i / current_user.staff) %> 
                    </tr>   
                <% end %>
            </tbody>

    </table>
</div>          

                <div class="row">
                    <div class=" col-md-2 panel panel-default pull-right" >
                        <div class="panel panel-heading ">
                            <h5 class="user-name">User: <% if current_user && current_user %> 
                            <%= current_user.name %>, 
                            Staff: <%= current_user.staff %>
                             <% end %>  
                          </h5>   
                        </div>     
                        <div class="panel-body">         
                            <h6 class="pull-right">Pappír Kostnaður Samtals:<%= number_with_precision(paper_total_cost.to_f, precision: 2) %> kr </h6><br>
                            <h6 class="pull-right">Fjöldi Trjáa vegna Pappírs notkunar:<%= number_with_precision(paper_total_trees.to_f, precision: 2) %> Tré </h6><br>
                             <h6 class="pull-right">Magn Pappírs f. hvert stöðugildi:<%= number_with_precision(paper_total_staff_ratio.to_f, precision: 2) %> Kg </h6>
                        </div>
                    </div>  
                </div>  

                <%= link_to 'New Paper', new_paper_path %>

我的papers_controller.rb

class PapersController < ApplicationController
before_action :set_paper, only: [:edit, :update, :show, :destroy]


def index
    @papers = Paper.all

end

def create
    @paper = Paper.new(paper_params)

    if @paper.save
        flash[:success] = "Messages sent."
        redirect_to paper_path(@paper)
    else
        flash[:danger] = "Error occured, message has not been sent."
        redirect_to new_paper_path
    end     


end

def new
    @paper = Paper.new
end

def edit
end

def show
end

def update
        if @paper.update(paper_params)
        flash[:success] = "Line was successfully updated"
        redirect_to papers_path(@paper)
    else
        render 'edit'
    end     

end

def destroy
    @paper.destroy
    flash[:danger] = "Line was successfully destroyed"
    redirect_to papers_path
end


private

def set_paper
    @paper = Paper.find(params[:id])
end
def paper_params
    params.require(:paper).permit(:paper_type, :date, :paper_weight, :paper_cost, :env_paper_weight)
end


end

my paper.rb Model

class Paper < ActiveRecord::Base
has_many :users 

end

Answer 1

您可以通过定义模型中的函数将计算移动到模型中。

第一个计算使用current_user，默认情况下不在模型中，因此必须是参数。另外两个只是使用纸张的属性;请原谅我糟糕的命名，我不清楚后两个指标是什么。

class Paper
  has_many :users

  def paper_weight_per_capita(current_user)
    paper_weight.to_i / current_user.staff
  end

  def paper_weight_metric1
    ( env_paper_weight / paper_weight)* 100)
  end

  def paper_weight_metric2
    (( paper_weight.to_f/1000)*15)
  end
end

在你看来

<%= paper.paper_weight_per_capita(current_user) %>
<%= paper.paper_weight_metric1 %>

如果您想要布局中的运行总计，那么您需要在每个页面上加载纸质对象。您可以使用application_controller before_action执行此操作，但some folks don't like this approach和here，但我认为这对您来说是合理的方式。

class ApplicationController < ActionController::Base
  before_action :load_running_totals

  def load_running_totals
    # method 1. Similar to how the calculation is done in the view.
    # @paper_weight_per_capita = Papers.all.map(&:paper_weight_per_capita, current_user).reduce(&:+)

    # method 2. does the summation in the database without having to load all the records into ruby. (weight needs to be a number in the db.)
    @paper_weight_per_capita = Papers.sum(:weight) / current_user.staff
  end
end

现在在任何视图（包括你的布局）中：

<%= @paper_weight_per_capita %>

如何在View to Model中移动计算？

1 个答案: