使用纯JavaScript禁用基于innerhtml的选择选项

Disable select option based on innerhtml with pure JavaScript

本文关键字：innerhtml 选项 选择 JavaScript      更新时间：2023-09-26

场景:用户通过HTML表单投票决定乘坐公共汽车进行实地考察。有三个选项:

    <select id="selectbox">
      <option>Berlin</option>
      <option>Munich</option>
      <option>Cologne</option>
    </select>
($tour是保存空闲座位的数组) 
<table class="status">
  <tr><td>Berlin: <span id="t1">available (<?php echo $tour[0]; ?> seats)</span></td></tr>
  <tr><td>Munich: <span id="t2">available (<?php echo $tour[1]; ?> seats)</span></td></tr>
  <tr><td>Cologne: <span id="t3">available (<?php echo $tour[2]; ?> seats)</span></td></tr>
</table>

如果空闲座位为0，我们使用普通JavaScript显示"对不起，已预订"信息:

// get content of status table
var t1 = document.getElementById("t1").innerHTML;
var t2 = document.getElementById("t2").innerHTML;
var t3 = document.getElementById("t3").innerHTML;
var bookedout = "sorry, booked out!"
    // check if condition is met
if (t1 == "available (0 seats)") {
    document.getElementById("t1").innerHTML = bookedout;
}
if (t2 == "available (0 seats)") {
    document.getElementById("t2").innerHTML = bookedout ;
}
if (t3 == "available (0 seats)") {
    document.getElementById("t3").innerHTML = bookedout ;
}

工作好。然而，现在到了我有点迷路的部分。上述条件还应该根据选项的innerHTML从#selectbox 中删除相应的选项。在jQuery中，我会使用#selectbox option:contains('stringhere')。

然而，我想用最纯粹的JavaScript来做。什么好主意吗?

这是相当直接的…

首先在你的html中给你的选项赋值:

<select id="selectbox">
  <option>Berlin</option>
  <option>Munich</option>
  <option>Cologne</option>
</select>

然后在js中:

var mySelect = document.getElementById("selectbox");
//function to get option values as array
function getOptionsArr() {
var optionsArray =[],options = mySelect.options; 
var i = 0, len = options.length;
// store the options value in an array
while (i < len)
{
  optionsArray.push(options[i++].value);
}
    return optionsArray;
}
var t1 = document.getElementById("t1").innerHTML;
var t2 = document.getElementById("t2").innerHTML;
var t3 = document.getElementById("t3").innerHTML;
var bookedout = "sorry, booked out!"
// check if condition is met
if (t1 == "available (0 seats)"){
    document.getElementById("t1").innerHTML = bookedout;
    //this will get the whole parent node and child node inner text we split at : and get the value
    var textArr = document.getElementById("t1").parentElement.innerText.split(':');
 // find the index of value from our array created above and remove that option from select
 mySelect.remove(getOptionsArr().indexOf(textArr [0]))
}
//repeat the same for other
if (t2 == "available (0 seats)"){
 document.getElementById("t2").innerHTML = bookedout ;
 var textArr = document.getElementById("t2").parentElement.innerText.split(':');
 mySelect.remove(getOptionsArr().indexOf(textArr [0]))
}
if (t3 == "available (0 seats)"){
document.getElementById("t3").innerHTML = bookedout ;
 var textArr = document.getElementById("t3").parentElement.innerText.split(':');
 mySelect.remove(getOptionsArr().indexOf(textArr [0]))
}

另外你可以用

来重构它
var mySelect = document.getElementById("selectbox");
//function to get option values as array
function getOptionsArr() {
var optionsArray =[],options = mySelect.options; 
var i = 0, len = options.length;
// store the options value in an array
while (i < len)
{
  optionsArray.push(options[i++].value);
}
    return optionsArray;
}
var t1 = document.getElementById("t1").innerHTML;
var t2 = document.getElementById("t2").innerHTML;
var t3 = document.getElementById("t3").innerHTML;
var bookedout = "sorry, booked out!"
// check if condition is met
if (t1 == "available (0 seats)"){
    doUpdateDOM("t1")
}
if (t2 == "available (0 seats)"){
doUpdateDOM("t2")
}
if (t3 == "available (0 seats)"){
doUpdateDOM("t3")
}
function doUpdateDOM(nodeID){
    document.getElementById(nodeID).innerHTML = bookedout;
    var textArr = document.getElementById(nodeID).parentElement.innerText.split(':');
 mySelect.remove(optionsArray.indexOf(textArr [0]))
}

假设select中选项的顺序与table元素中的顺序相对应，您可以简单地执行如下操作:

var select = document.getElementById('selectbox');
var table = document.getElementsByClassName('status').item(0);
var rows = table.rows;
var bookedout = " sorry, booked out!";
// check whether an option is bookedout
// and save its state to a new array.
var bookedOutState = [].slice.call(rows).map(function(row) {
  var match = row.children[0].textContent.match(/'d/);
  if (+match[0] === 0) {
    row.children[0].textContent = match['input'].substr(0, match['input'].indexOf(':') + 1) + bookedout;
    return false;
  }
  return true;
})
// go over the new created array and remove
// options from select according to the saved state.
bookedOutState.forEach(function(state, idx) {
  if (!state) {
    select.removeChild(select.children[idx])
  }
})
<select id="selectbox">
  <option>Berlin</option>
  <option>Munich</option>
  <option>Cologne</option>
</select>
<table class="status">
  <tr><td>Berlin: <span id="t1">available 0 seats</span></td></tr>
  <tr><td>Munich: <span id="t2">available 1 seats</span></td></tr>
  <tr><td>Cologne: <span id="t3">available 2 seats</span></td></tr>
</table>

相关文章：