javascript - 当按钮具有特定值时，将类添加到按钮

Question

是否可以在按钮的值发生变化时向已经具有类的按钮添加类？

示例:

按钮值:Europe West --> 将 EuWest 类添加到当前按钮类。

所以它会显示<button class="buttonclass EuWest" value="Europe West">Europe West</button>

例如，每当值更改为 North America 时，EuWest 类就会删除并更改为 NorthAmerica。

我想这样做是因为稍后在搜索特定于服务器的 API 时，我相信这是某些事情所需要的。

在我当前的代码之下。

$(document).ready(function(){
  var regionDropDown = $('.region_dropdown_section'),
      regionButton = regionDropDown.find('button'),
      regionList = regionDropDown.find('.region_dropdown_content').children();

  $(regionList).on('click', function(e){
    var region = e.target;
    regionButton.text(region.text).val(region.text);
  });
});

html, body, div, span, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, code, del, dfn, em, img, q, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td {
  margin: 0;
  padding: 0;
  border: 0;
  font-size: 100%;
  font-family: 'Helvetica Neue', Helvetica, Arial, Sans-Serif;
  vertical-align: baseline;
  outline: none;
}

body {
  background: url(../images/background/body_background.png) no-repeat center center fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

.logo {
  width: 500px;
  height: 225px;
  margin: auto;
  display: block;
  margin-top: 50px;
  margin-bottom: 50px;
}

.SearchSummoners {
  margin: auto;
  width: 35%;
  padding: 10px;
  background-color: rgba(0, 0, 0, 0.7);
  border: 1px solid;

  -moz-border-image: -moz-linear-gradient(top, #006184 0%, #303142 100%);
  -webkit-border-image: -webkit-linear-gradient(top, #006184 0%, #303142 100%);
  border-image: linear-gradient(to bottom, #006184 0%, #303142 100%);
  border-image-slice: 1;
}

/* Dropdown Button */
.dropbtn {
background-color: #19A5D4;
color: white;
padding: 4px;
font-size: 12px;
border: none;
cursor: pointer;
height: 40px;
width: 100%;
}



/* Dropdown Content (Hidden by Default) */
.region_dropdown_content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    max-width: 335px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
}

.region_dropdown_section {
  overflow: hidden;
  width: 20%;
}

/* Links inside the dropdown */
.region_dropdown_content a {
    color: black;
    text-decoration: none;
    display: inline-block;
    width: 45%;
    margin: 0;
    vertical-align: top;
    padding: 10px 0px 10px 10px;
}

/* Change color of dropdown links on hover */
.region_dropdown_content a:hover {background-color: #f1f1f1}

/* Show the dropdown menu on hover */
.region_dropdown_section:hover .region_dropdown_content {
    display: block;
}

/* Change the background color of the dropdown button when the dropdown content is shown */
.region_dropdown_section:hover .dropbtn {
    background-color: #1491BA;
}

.Searchbox_Summoners {
  margin: auto;
  display: block;
  width: 65%;
}


#SearchBox {
    	margin-right: 0;
    	margin-left: 0;
    	width: 80%;
    	background-color: white;
    	height: 40px;
    	float: left;
    }

        .region_dropdown_section {
        	position: inherit;
        	display: inline-block;
        	max-width: 100% !important;
          overflow: hidden;
        }

#SearchInput{
		width: 92%;
		line-height: 40px;
		background: white;
		border: 0;
		outline: 0;
		margin: 0;
		padding: 0;
		margin-left: 20px;
    font-size: 24px;
	}

  /* Region Sprites */

.BR, .EUNE, .EUW, .JP, .KR, .LAN, .LAS, .NA, .OCEANIA, .RUS, .TURKEY{
	background: url(../images/icons/regions/regions.png) no-repeat;
  display: inline-block;
  overflow: hidden;
  vertical-align: middle;
  padding-right: 15px;
}

.BR{
	background-position: -2px -2px ;
	width: 26px;
	height: 28px;
}

.EUNE{
	background-position: -2px -35px ;
	width: 26px;
	height: 28px;
}

.EUW{
	background-position: -2px -70px ;
	width: 26px;
	height: 28px;
}

.JP{
	background-position: -2px -105px ;
	width: 26px;
	height: 28px;
}

.KR{
	background-position: -2px -140px ;
	width: 26px;
	height: 28px;
}

.LAN{
	background-position: -2px -175px ;
	width: 26px;
	height: 28px;
}

.LAS{
	background-position: -2px -210px ;
	width: 26px;
	height: 28px;
}

.NA{
	background-position: -2px -245px ;
	width: 26px;
	height: 28px;
}

.OCEANIA{
	background-position: -2px -280px ;
	width: 26px;
	height: 28px;
}

.RUS{
	background-position: -2px -315px ;
	width: 26px;
	height: 28px;
}

.TURKEY{
	background-position: -2px -350px ;
	width: 26px;
	height: 28px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<?php define('DeniedAccessFiles', TRUE); ?>

<?php include 'header.php'; ?>
<div class="logo">
    <a href="<?php echo "http://" . $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI']; ?>"><img src="images/logo.png"></a>
</div>
  <div class="SearchSummoners">
      <div id="SearchBox">
        <form method="POST" autocomplete="off">
          <input id="SearchInput" value="Enter Summoners Name"  onfocus="if(this.value  == 'Enter Summoners Name') { this.value = ''; } " onblur="if(this.value == '') { this.value = 'Enter Summoners Name'; }"  type="text" name="SummonerName"></input>
        </form>
      </div>
      <div class="region_dropdown_section">
        <button class="dropbtn">Select Region</button>
        <div class="region_dropdown_content">
          <a href="?link=NA"><span class="NA"></span>North America</a>
          <a href="?link=EUW"><span class="EUW"></span>Europe West</a>
          <a href="?link=EUNE"><span class="EUNE"></span>Europe NE</a>
          <a href="?link=LAN"><span class="LAN"></span>LAN</a>
          <a href="?link=LAS"><span class="LAS"></span>LAS</a>
          <a href="?Link=OC"><span class="OCEANIA"></span>Oceania</a>
          <a href="?link=BR"><span class="BR"></span>Brazil</a>
          <a href="?link=KR"><span class="KR"></span>Korea</a>
          <a href="?link=JP"><span class="JP"></span>Japan</a>
          <a href="?link=TUR"><span class="TURKEY"></span>Turkey</a>
          <a href="?link=RUS"><span class="RUS"></span>Russia</a>
        </div>
      </div>
  </div>
<?php include 'footer.php'; ?>

Answer 1

要使此脚本正常工作，您需要进行一些更改。我会添加 data字段到 <a href>单击标签时，jQuery 知道该做什么。然后我会实现 ajax，这样页面就不会重新加载(否则您需要在此页面上执行一些 PHP 以在重新加载时保留设置)。看看这是否是您想要做的:

演示: https://jsfiddle.net/rtasdses/

表格:

<form method="POST" autocomplete="off">
  <div class="SearchSummoners">
      <div id="SearchBox">
          <input id="SearchInput" placeholder="Enter the Summoner Name" name="SummonerName" />
      </div>
      <div class="region_dropdown_section">
        <button class="dropbtn">Select Region</button>
        <div class="region_dropdown_content">
          <a href="#" data-addclass="selected"><span class="NA"></span>North America</a>
          <a href="#" data-addclass="blue"><span class="EUW"></span>Europe West</a>
          <a href="#" data-addclass="pink"><span class="EUNE"></span>Europe NE</a>
          <a href="#" data-addclass="green"><span class="LAN"></span>LAN</a>
          <a href="#" data-addclass="blue"><span class="LAS"></span>LAS</a>
          <a href="#" data-addclass="selected"><span class="OCEANIA"></span>Oceania</a>
          <a href="#" data-addclass="blue"><span class="BR"></span>Brazil</a>
          <a href="#" data-addclass="pink"><span class="KR"></span>Korea</a>
          <a href="#" data-addclass="blue"><span class="JP"></span>Japan</a>
          <a href="#" data-addclass="green"><span class="TURKEY"></span>Turkey</a>
          <a href="#" data-addclass="blue"><span class="RUS"></span>Russia</a>
        </div>
      </div>
  </div>
</form>
<div id="section2"></div>

jQuery:

$(document).ready(function(){
    // Set the current class
    var currClass = false;
    // On click
    $('.region_dropdown_content > a').click(function(e){
        // Stop (just incase)
        e.preventDefault();
        // Assign current class
        var addClass    =   $(this).data('addclass');
        // Extract the text from the a tag
        var thisTxt     =   $(this).text();
        // If not empty, remove it
        if(currClass) {
            $('.dropbtn').removeClass(currClass);
            $('.SearchSummoners').removeClass(currClass);
        }
        // Now assign the current class to save
        currClass   =   addClass;
        // Add the extracted <a> text into the button tag to change name
        $('.dropbtn').addClass(addClass).text(thisTxt);
        // Add the class to the button
        $('.SearchSummoners').addClass(addClass);
        // this will send your request to whatever page
        // that will run your search
        $.ajax({
            // Url of the page that searches
            url:'/url/to/ajax/dispatcher.php',
            // This will submit to the above page using post
            data: {
                "search": addClass,
                "term": $("#SearchInput").val()
            },
            type: 'post',
            // This will place the response (html possibly) into a container
            success: function(response) {
                // Put html back into placeholder
                $('#section2').html(response);
            }
        });
    });
});

CSS(我只是将这部分添加到底部以进行演示):

.selected {
    background-color: orange;
}
.blue  {
    background-color: red;
}
.pink  {
    background-color: pink;
}
.green  {
    background-color: green;
}