使用PHP在同一页面上的下拉菜单的所选项目

Question

i have created the drop down menu using php and i want to use the selected value of menu on url of the current page. How can i do this without redirecting to the next page. the code for creating dropdown menu is:

echo '<select name="Company">';
if($data['count']>0){
foreach($data['results'] as $key=>$value){
echo "<option value='".$value['CID']."'>".$value['Name']."</option>";
}
}
echo "</select>";

Answer 1

Hum? Dont know what you exactly want. You want to create a dropdown menu and use the selected value on the current php page?

That wont work. Ill show you how it works:

PHP renders page -> gives it to you.

When you see the page, the php-script is already done. So you have to call your page again and give it the value via $_POST ...

echo <form action="page.php" method="post">
echo '<select name="Company">';
if($data['count']>0) {
    foreach($data['results'] as $key=>$value){
        echo "<option value='".$value['CID']."'>".$value['Name']."</option>";
    }
}
echo "</select></form>";

... or $_GET (this only works in combination with JS!) ...

echo "<a href='page.php?company=companyname'>Im a link!</a>"

Answer 2

You need to get drop down value using javascript or JQuery

In Javascript:

<script type="text/javascript">
var myselect=document.getElementById("Company")
for (var i=0; i<myselect.options.length; i++){
 if (myselect.options[i].selected==true){
  alert("Selected Option's index: "+i)
  break
 }
}
</script>

In JQuery

$('select[name=Company]').val()

Answer 3

It's not entirely clear how you want to use this value, but you can refer to it on the same page using javascript. Consider the code below, which will update the line "Your company is:" whenever a new option is selected from the dropdown box.

<script type="application/javascript">
    function update_box() {
        selected_value = document.getElementById('company_dropdown').value;
        document.getElementById('your_company').innerText = selected_value;
    }
</script>

<form action="page.php" method="post" id="my_form" name="my_form" onchange="update_box()">
    <select name="company_dropdown" id="company_dropdown">
        <option value='A'>A</option>
        <option value='B'>B</option>
        <option value='C'>C</option>
    </select>
</form>


Your company is: <span id="your_company" name="your_company"></span>

Answer 4

If I am getting it right, you want to use the selected value from dropdown on the same page url via querystring. You can do that like following:-

echo '<select name="Company" onchange="location.href = location.href+'?var=' + this.value">';
if($data['count']>0){
foreach($data['results'] as $key=>$value){
    echo "<option value='".$value['CID']."'>".$value['Name']."</option>";
}
}
echo "</select>";

When you will change the value in dropdown, current page will refresh with the selected option value in querystring. You can use the querystring value as following:-

<?php echo isset($_GET['var']) ? $_GET['var'] : ''; ?>

Answer 5

You can also do it via use of hash value without refreshing the page

When ever you change the dropdown on the onchange event you can write the code

onchange="window.location.hash(this.value); "

it will set a hash value in the url and then you can write a function which will detect the change in the hash value as the page is not refreshing you need to track the change in the hash value and then you can show the selected menu on the basis oh the hash value.

use this to detect the change in the hash value

$(document).ready(function() {
    $(window).bind('hashchange', function(e) {
        var hashStr = window.location.hash;
        hashStr = hashStr.substring(1, hashStr.length);
        hashArray = hashStr.split('&');
        // here you will get the array of all the parameters you passed in the array 
    });
});