CODEWITHSUNDEEP
htmlselectlimit
Hafizul Amri
Hafizul Amri

Reputation: 2663

HTML Multiselect Limit

Is it possible to set limit to multipleselect?

Below is an example code where user can select more than 1 value.

<select multiple="multiple" name="choose">
<option value="1">Value 1</option>
<option value="2">Value 2</option>
<option value="3">Value 3</option>
<option value="4">Value 4</option>
<option value="5">Value 5</option>
<option value="6">Value 6</option>
</select>

But, how to limit user to select not more than 3 value. Any idea?

Upvotes: 18

Views: 51011

Answers (4)

08Hawkeye
08Hawkeye

Reputation: 246

RedFilter has the right idea with validating by javascript. Haven't tested, but you could do something like:

var options = document.all.tags("option");
var selectedCounter = 0;
    
for (var i=0; i < options.length; i++) {
   if (options[i].selected) {
      selectedCounter++;
   }
   checkCounter();
}

function checkCounter() {
   //disable all options here
}

Upvotes: 0

arcyqwerty
arcyqwerty

Reputation: 10675

Script that will disallow more than 3 elements to be selected (as opposed to just validating it at submit time).

http://jsfiddle.net/v33sszgp/

var verified = [];
document.querySelector('select').onchange = function(e) {
  if (this.querySelectorAll('option:checked').length <= 3) {
      verified = Array.apply(null, this.querySelectorAll('option:checked'));
  } else {
    Array.apply(null, this.querySelectorAll('option')).forEach(function(e) {
        e.selected = verified.indexOf(e) > -1;
    });
  }
}

Note there's some additional complexity related to preventing the item from actually being selected on the select and that it rather validates a user's actions and reverts it if it's invalid.

Upvotes: 3

D&#39;Arcy Rittich
D&#39;Arcy Rittich

Reputation: 171371

You would do this via javascript on the client side, and then add a check on the server side as well in case the client has disabled javascript.

Here is some basic client side code to give you an idea:

<html>
    <body>
        <form onsubmit="validate()">
            <select multiple="multiple" id="choose" name="choose"> 
                <option value="1">Value 1</option> 
                <option value="2">Value 2</option> 
                <option value="3">Value 3</option> 
                <option value="4">Value 4</option> 
                <option value="5">Value 5</option> 
                <option value="6">Value 6</option> 
            </select><br>
            <input type="submit">
        </form>
        <script>
        function validate()
        {
            var selectChoose = document.getElementById('choose');
            var maxOptions = 2;
            var optionCount = 0;
            for (var i = 0; i < selectChoose.length; i++) {
                if (selectChoose[i].selected) {
                    optionCount++;
                    if (optionCount > maxOptions) {
                        alert("validation failed, not submitting")
                        return false;
                    }
                }
            }
            return true;
        }
        </script>
    </body>
</html>

Upvotes: 6

Alex Rashkov
Alex Rashkov

Reputation: 10015

You can use jQuery 

  $("select").change(function () {
      if($("select option:selected").length > 3) {
          //your code here
      }
  });

Upvotes: 16

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