Javascript显示/隐藏基于下拉菜单 [英] Javascript show/hide based on dropdown
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问题描述
我已经有了下面的代码来显示/隐藏两个基于下拉选择的表单元素。它在使用ID的页面上有一个表单的单个实例时起作用。现在有多种形式，它们使用类。我试过 getElementsByClass 但由于某种原因，它不起作用。
这里是Javascript：
function Toggle（obj）{
var val = obj.value;
if（！obj.m）{obj.m =''; }
if（！obj.m.match（val））{obj.m + ='，'+ val +'，'; }
var hide = obj.m.split（'，'）;
for（var zxc0 = 0; zxc0< hide.length; zxc0 ++）{
if（document.getElementsByClassName（hide [zxc0]））{
document.getElementsByClassName（hide [zxc0]）的style.display = '无';
}
}
var show = val.split（'，'）;
for（var zxc1 = 0; zxc1< show.length; zxc1 ++）{
if（document.getElementsByClassName（show [zxc1]））{
document.getElementsByClassName（show [zxc1]）的style.display = '';
和HTML：
< form class =contactname =contactaction =＃method =post>
< label>您是如何知道我们的：< / label>
< div id =style-select>
< select name =howonChange =Toggle（this）;类= 下拉菜单 >
< option value =互联网搜索>互联网搜索< /选项>
< option value =Facebook> Facebook< / option>
< option value =Twitter> Twitter< / option>
< option value =LinkedIN> LinkedIN< / option>
< option value =Referral，Referral2> Referral< / option>
< option value =Other，Other2>其他< / option>
< / select>
< / div>
< label class =Referralstyle =display：none;>推荐人：< / label>
< input name =Referral2style =display：none; class =hidden-txt Referral2>
< label class =其他style =display：none;>请指定：< / label>
< input name =Other2value =style =display：none; class =hidden-txt Other2>
...
< / form>
从下拉列表中选择引荐时，标签 class = Referral 并输入 class = Referral2 应该出现。当选择Other时，标签 class = Other 并且输入 class = Other2 应该出现（并且引用应该隐藏）。
解决方案
我认为使用JQuery可能会更快/更容易，除非需要纯JS。
工作示例： http://jsfiddle.net/p8ARq / 2 /
JQuery
$（select）。change（function（）{
//隐藏所有可选元素。 （$（this）.val（）==Referral）{
$（select option：selected）。 （'.referral'）.css（'display'，'block'）;
} else if（$（this）.val（）==Other）{
$（'。other '）.css（'display'，'block'）;
}
}）;
}）;
HTML
< form class =contactname =contactaction =＃method =post>
< label>您是如何知道我们的：< / label>
< div id =style-select>
< select name =howclass =dropdown>
< option value =互联网搜索>互联网搜索< /选项>
< option value =Facebook> Facebook< / option>
< option value =Twitter> Twitter< / option>
< option value =LinkedIN> LinkedIN< / option>
< option value =Referral> Referral< / option>
< option value =其他>其他< / option>
< / select>
< / div>
< label class =optional referralstyle =display：none;> Referred By：< / label>
< input class =optional referralname =Referral2style =display：none;类= 隐藏-TXT >
< label class =optional otherstyle =display：none;>请指定：< / label>
< input class =optional othername =Other2value =style =display：none;类= 隐藏-TXT >
< label for =注册class =text-checkbox>将我添加到您的电子邮件列表< / label>
< input type =checkboxname =signupvalue =Yesclass =checkbox>
< button class =send>提交< / button>
< / form>
I already have the following code to show/hide two form elements based on a dropdown selection. It worked when there was a single instance of a form on the page using IDs. Now there's multiple forms, which use classes. I've tried getElementsByClass but for some reason it's not working.
Here is the Javascript:
function Toggle(obj){
var val=obj.value;
if (!obj.m){ obj.m=''; }
if (!obj.m.match(val)){ obj.m+=','+val+','; }
var hide=obj.m.split(',');
for (var zxc0=0;zxc0<hide.length;zxc0++){
if (document.getElementsByClassName(hide[zxc0])){
document.getElementsByClassName(hide[zxc0]).style.display='none';
}
}
var show=val.split(',');
for (var zxc1=0;zxc1<show.length;zxc1++){
if (document.getElementsByClassName(show[zxc1])){
document.getElementsByClassName(show[zxc1]).style.display='';
}
}
}
And the HTML:
<form class="contact" name="contact" action="#" method="post">
<label>How did you hear about us:</label>
<div id="styled-select">
<select name="how" onChange="Toggle(this);" class="dropdown">
<option value="Internet Search">Internet Search</option>
<option value="Facebook" >Facebook</option>
<option value="Twitter" >Twitter</option>
<option value="LinkedIN" >LinkedIN</option>
<option value="Referral,Referral2" >Referral</option>
<option value="Other,Other2">Other</option>
</select>
</div>
<label class="Referral" style="display:none;">Referred By:</label>
<input name="Referral2" style="display:none;" class="hidden-txt Referral2">
<label class="Other" style="display:none;">Please Specify:</label>
<input name="Other2" value="" style="display:none;" class="hidden-txt Other2">
...
</form>
When referral is selected from the dropdown, the label class=Referral and input class=Referral2 should appear. Upon selection of Other, label class=Other and input class=Other2 should appear (and referral should hide).
解决方案
I think it might be quicker/easier to use JQuery unless pure JS is a requirement.
Working Example: http://jsfiddle.net/p8ARq/2/
JQuery
$("select").change(function () {
// hide all optional elements
$('.optional').css('display','none');
$("select option:selected").each(function () {
if($(this).val() == "Referral") {
$('.referral').css('display','block');
} else if($(this).val() == "Other") {
$('.other').css('display','block');
}
});
});
HTML
<form class="contact" name="contact" action="#" method="post">
<label>How did you hear about us:</label>
<div id="styled-select">
<select name="how" class="dropdown">
<option value="Internet Search">Internet Search</option>
<option value="Facebook" >Facebook</option>
<option value="Twitter" >Twitter</option>
<option value="LinkedIN" >LinkedIN</option>
<option value="Referral" >Referral</option>
<option value="Other">Other</option>
</select>
</div>
<label class="optional referral" style="display:none;">Referred By:</label>
<input class="optional referral" name="Referral2" style="display:none;" class="hidden-txt">
<label class="optional other" style="display:none;">Please Specify:</label>
<input class="optional other" name="Other2" value="" style="display:none;" class="hidden-txt">
<label for="signup" class="text-checkbox">Add me to your email list</label>
<input type="checkbox" name="signup" value="Yes" class="checkbox">
<button class="send">Submit</button>
</form>
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