Question

Textbox in jsp that allows only text numbers and comma.

this is to seperate userids.

each userid has to be 8 chars in length and i need to enter multiple userids in the textbox.

eg:

correct format is below

asakthi1,psubhadr,tpradee4

it should not end like(with a comma at the end.)(incorrect format)

asakthi1,psubhadr,tpradee4,

this i need to do using javascript.(No Jquery please.)

am scratching my head on this..Any help would be appreciated.

Answer 1

You could attach an onchange event handler to the <input type="text"> that will perform the validation using a regular expression like, for instance, this one: ^(([A-Za-z0-9]{8}),)*[A-Za-z0-9]{8}$.

If a username is a combination of 8 letters or numbers, this expression would accept any number of usernames followed by comma, and at least one final username without a comma. Notice the {8} element forces a match of exactly 8 characters.

If validation fails, it’s up to you how to show it to the user. This example will be showing an alert and clearing the input.

<input type="text" onchange="if (!validate(this.value)) { alert('incorrect value'); this.value = ''; }">

<script>
function validate​(value){
    return value.match(new RegExp("^(([A-Za-z0-9]{8}),)*[A-Za-z0-9]{8}$")) != null;
}​
</script>

Here is a sample JSFiddle to see the expression at work.