在Rails应用中使用Javascript显示和隐藏

show and hide using Javascript in a Rails app

本文关键字：Javascript 显示 隐藏 Rails 应用      更新时间：2023-09-26

我是JavaScript和rails的新手。我正在建立一个网站在rails上的ruby和我试图在视图中使用JavaScript。我需要隐藏和显示一个表的一些元素，我有一些脚本任务下来，它只适用于表的第一行。有更好的方法吗?谢谢你的帮助。我需要每个按钮显示或隐藏表

中的相应元素。

application.html 

    <!DOCTYPE html>
<script>
function changeColor(newColor) {
    document.getElementById("para1").style.display = "none"
    document.getElementById("para2").style.display = "none"
    document.getElementById("para3").style.display = "none"
    document.getElementById("para4").style.display = "block"
    document.getElementById("para5").style.display = "none"
  }

  function show(newColor) {
    document.getElementById("para1").style.display = "block"
    document.getElementById("para2").style.display = "block"
    document.getElementById("para3").style.display = "block"
    document.getElementById("para4").style.display = "none"
    document.getElementById("para5").style.display = "block"
  }
  </script>
<html>
<head>
  <title>VincentricData</title>
  <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track' => true %>
  <%= stylesheet_link_tag    "defaults", media: "all", "data-turbolinks-track" => true %>
  <%= csrf_meta_tags %>
</head>
<body>
<%= yield %>
</body>
</html>

index . html 

<h1>Listing vehicles</h1>

    <table>
      <thead>
        <tr>
          <th>Year</th>
          <th>Make</th>
          <th>Model</th>
          <th>Msrp</th>
          <th>Rating</th>
          <th>Total operating costs</th>
          <th colspan="3"></th>
        </tr>
      </thead>
      <tbody>
        <% @vehicles.each do |vehicle| %>
          <tr>
            <td><%= vehicle.year %></td>
            <td><%= vehicle.make %></td>
            <td><%= vehicle.model %></td>
            <td><div id="para1" ><%= vehicle.msrp %></div></td>
            <td><div id="para2" ><%= vehicle.rating %></div></td>
            <td><div id="para3" ><%= vehicle.total_operating_costs %></div></td>
            <td><div id="para4" ><button onclick="show('#00FFFF');">Show</button></div></td>
            <td><div id="para5" ><button onclick="changeColor('#00FFFF');">hide</button></div></td>
            <td><%= link_to 'Edit', edit_vehicle_path(vehicle) %></td>
            <td><%= link_to 'Destroy', vehicle, method: :delete, data: { confirm: 'Are you sure?' } %></td>
          </tr>
        <% end %>
      </tbody>
    </table>
    <br>
    <%= link_to 'New Vehicle', new_vehicle_path %>

首先，如果行处于循环中，则不能为元素提供硬编码ID，因为会有多个具有相同ID的HTML元素，这绝对是非常糟糕的。给你的元素一个类，你可以想复制多少次就复制多少次。

第二，您可以(如果可能的话，也许应该)使用jQuery来完成这类事情。它真的，真的比纯javascript更直观，更容易。

<script src='/somewhere/jquery.min.js'></script>
<script>
    (function ($) {
        // Here you are sure that jQuery is included in your HTML page
        $(function () {
            // Now the DOM is fully loaded, you can use some javascript without problem
            // Listen a click on each ".para4" element : (class='para4')
            $('.para4').on('click', function (event) {
                // Get the parent <tr> element
                var $tr = $(this).closest('tr');
                // On this parent <tr>, display all .para elements
                $tr.find('.para').show();
                /*
                This is equivalent to :
                $tr.find('.para').css('display', 'block');
                */
                // Then hide the .para4 one only.
                $tr.find('.para4').hide();
                /*
                This is equivalent to :
                $tr.find('.para4').css('display', 'none');
                */
            });
            // Listen a click on each ".para5" element : (class='para5')
            $('.para5').on('click', function (event) {
                // Get the parent <tr> element
                var $tr = $(this).closest('tr');
                // On this parent <tr>, hide all .para elements
                $tr.find('.para').hide();
                /*
                This is equivalent to :
                $tr.find('.para').css('display', 'none');
                */
                // Then display the .para4 one only.
                $tr.find('.para4').show();
                /*
                This is equivalent to :
                $tr.find('.para4').css('display', 'block');
                */
            });
        });
    })(window.jQuery);
</script>

小提琴:http://jsfiddle.net/9uRps/

如果没有jQuery，你必须使用循环和事件监听器: 
// Find all your .para4 elements
var para4Array = document.getElementsByClassName('para4');
var para4Length = para4Array.length;
// For each of them, listen for a click event
while (para4Length--) {
    para4Array[para4Length].addEventListener('click', function (event) {
        // Find the parent's <tr>
        var tr = this.parentNode.parentNode;
        // Display all .para children of this <tr>
        tr.querySelectorAll('.para').style.display = 'block';
        // Then hide the .para4 one
        tr.querySelectorAll('.para4').style.display = 'none';
    });
}
// Find all your .para5 elements
var para5Array = document.getElementsByClassName('para5');
var para5Length = para5Array.length;
// For each of them, listen for a click event
while (para5Length--) {
    para5Array[para5Length].addEventListener('click', function (event) {
        // Find the parent's <tr>
        var tr = this.parentNode.parentNode;
        // Hide all .para children of this <tr>
        tr.querySelectorAll('.para').style.display = 'none';
        // Then display the .para4 one
        tr.querySelectorAll('.para4').style.display = 'block';
    });
}
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