【发布时间】：2021-02-10 17:24:29
【问题描述】：
我只想在表格的第一行显示余额。
index.html.erb
<p id="notice"><%= notice %></p>
<h1>Expenses</h1>
<% balance = 0 %>
<style>
table, th, td {
border: 1px solid black;
border-collapse: collapse;
}
</style>
<div class="container">
<table id="table_id" style="width:100%">
<thead>
<tr>
<th>Date</th>
<th>Particulars</th>
<th>Debit</th>
<th>Credit</th>
<th>Balance</th>
</tr>
</thead>
<tbody>
<% @expenses.each do |expense| %>
<tr>
<td><%= expense.date.strftime('%d/%m/%Y') %></td>
<td><%= expense.particulars %></td>
<td class="pos"><%= expense.debit %></td>
<td class="neg"><%= expense.credit %></td>
<% balance += expense.debit.to_f-expense.credit.to_f %>
<% color = balance >= 0 ? "pos" : "neg" %>
<td class="<%= color %>"><%= number_with_precision(balance.abs, :delimiter => ",", :precision => 0) %></td>
<!--<td><%= link_to 'Show', expense %></td>-->
<!-- <td><%= link_to 'Edit', edit_expense_path(expense) %></td>-->
<!-- <td><%= link_to 'Destroy', expense, method: :delete, data: { confirm: 'Are you sure?' } %></td>-->
</tr>
<% end %>
</tbody>
</table>
</div>
<br>
<%= link_to 'New Expense', new_expense_path %>
expenses_controller.rb
class ExpensesController < ApplicationController
before_action :set_expense, only: %i[ show edit update destroy ]
# GET /expenses or /expenses.json
def index
@expenses = Expense.all
# @expenses = Expense.order("created_at ASC")
# @expenses = Expense.order("created_at DESC")
end
# GET /expenses/1 or /expenses/1.json
def show
end
# GET /expenses/new
def new
@expense = Expense.new
end
# GET /expenses/1/edit
def edit
end
# POST /expenses or /expenses.json
def create
@expense = Expense.new(expense_params)
respond_to do |format|
if @expense.save
format.html { redirect_to @expense, notice: "Expense was successfully created." }
format.json { render :show, status: :created, location: @expense }
else
format.html { render :new, status: :unprocessable_entity }
format.json { render json: @expense.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /expenses/1 or /expenses/1.json
def update
respond_to do |format|
if @expense.update(expense_params)
format.html { redirect_to @expense, notice: "Expense was successfully updated." }
format.json { render :show, status: :ok, location: @expense }
else
format.html { render :edit, status: :unprocessable_entity }
format.json { render json: @expense.errors, status: :unprocessable_entity }
end
end
end
# DELETE /expenses/1 or /expenses/1.json
def destroy
@expense.destroy
respond_to do |format|
format.html { redirect_to expenses_url, notice: "Expense was successfully destroyed." }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_expense
@expense = Expense.find(params[:id])
end
# Only allow a list of trusted parameters through.
def expense_params
params.require(:expense).permit(:date, :particulars, :debit, :credit)
end
end
我尝试在费用控制器中使用@expenses = Expense.order("created_at ASC") 和@expenses = Expense.order("created_at DESC")，但无法获得真正的余额。
实际上，我必须用适当的余额条目从下到上显示填充的条目。
欢迎提出任何建议。
提前谢谢你。
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