Getting the option value without submitting a form [duplicate]

Question

I want to use the user selected option value without submitting a form. Here is my HTML code

Combo Box<br>
<select name="select1">
<option value="IVP" selected>IVP</option>
<option value="SURTEK">SURTEK</option>
<option value="GUITARTUNER">GUITARTUNER</option>
<option value="OTHER">OTHER</option>
</select>

I want to take the selected option value to a php variable, so that according to option value a new set of data could be displayed. Thanks

Naryl · Accepted Answer

as other people suggested, you should use AJAX. I'd recommend looking into javascript/Jquery examples of a AJAX call.

I guess you want to modify a portion of the web depending on the option the user selects, the best way to do this is have a separate PHP script that receives the selected option (captured in javascript/JQuery) and returns the new HTML you want to display.

For example in Jquery to get the selected option:

var selected_option_value=$("#select1 option:selected").val();

Also in Jquery to do a AJAX call, passing the value using POST:

  $.post("script_that_receives_value.php", {option_value: selected_option_value},
      function(data){ //this will be executed once the `script_that_receives_value.php` ends its execution, `data` contains everything said script echoed.
          $("#place_where_you_want_the_new_html").html(data);
      }
  );

Hope this helps!

EDIT: let's give a bit more of detail to the example above:

let's say you have a index.html page where you have the <select name="select1">given in your question:

the first step would be to link an event when someone select one of the options, how to do this:

1- First way to do it:

<select name='select1' id='select1' onchange='load_new_content()'>

This way when someone changes the selected value of the <select> list the javascript function load_new_content() will be executed. Notice I have added id='select1' to the tag, this is used to search this element in javascript/JQuery, you should always use the id attribute if you need to use that tag in javascript/JQuery.

2- Second way, link the event using JQuery:

To do this you should have a <script> tag inside the <head> of index.html. Inside this <script> tag you should have:

$(document).ready(function(){
      // everything here will be executed once index.html has finished loading, so at the start when the user is yet to do anything.
      $("#select1").change(load_new_content()); //this translates to: "when the element with id='select1' changes its value execute load_new_content() function"
});

Regardless the option you want to use you now need this load_new_content() function. It should also be declared inside the <script> tag of the <head> tag, just like the $(document).ready function.

function load_new_content(){
     var selected_option_value=$("#select1 option:selected").val(); //get the value of the current selected option.

     $.post("script_that_receives_value.php", {option_value: selected_option_value},
         function(data){ //this will be executed once the `script_that_receives_value.php` ends its execution, `data` contains everything said script echoed.
              $("#place_where_you_want_the_new_html").html(data);
              alert(data); //just to see what it returns
         }
     );
}

Now the only thing left is this script_that_receives_value.php:

<?php
     $selected_option=$_POST['option_value'];

     //Do what you need with this value, then echo what you want to be returned.

     echo "you have selected the option with value=$selected_option";
?>

Prasanth Bendra · Answer

Use AJAX, while selecting a option in dropdown trigger a jQuery function and send values to server page by AJAX

HTML page :

<html>
<head>
<script>
function showUser(str)
{
if (str=="")
  {
  document.getElementById("txtHint").innerHTML="";
  return;
  }
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","getuser.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>

<form>
<select name="users" onchange="showUser(this.value)">
<option value="">Select a person:</option>
<option value="1">Peter Griffin</option>
<option value="2">Lois Griffin</option>
<option value="3">Glenn Quagmire</option>
<option value="4">Joseph Swanson</option>
</select>
</form>
<br>
<div id="txtHint"><b>Person info will be listed here.</b></div>

</body>
</html>

PHP page (getuser.php) :

<?php
$q=$_GET["q"];

$con = mysql_connect('localhost', 'peter', 'abc123');
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("ajax_demo", $con);

$sql="SELECT * FROM user WHERE id = '".$q."'";

$result = mysql_query($sql);

echo "<table border='1'>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Age</th>
<th>Hometown</th>
<th>Job</th>
</tr>";

while($row = mysql_fetch_array($result))
  {
  echo "<tr>";
  echo "<td>" . $row['FirstName'] . "</td>";
  echo "<td>" . $row['LastName'] . "</td>";
  echo "<td>" . $row['Age'] . "</td>";
  echo "<td>" . $row['Hometown'] . "</td>";
  echo "<td>" . $row['Job'] . "</td>";
  echo "</tr>";
  }
echo "</table>";

mysql_close($con);
?>

Ref: http://www.w3schools.com/php/php_ajax_database.asp

Getting the option value without submitting a form [duplicate]

Tags:

html

php

HaK

Video Answer

2 Answers

Naryl

Prasanth Bendra

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Getting the option value without submitting a form [duplicate]

Tags:

html

php

HaK

Video Answer

2 Answers

Naryl

Prasanth Bendra

Related questions

Recent Activity

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