CODEWITHSUNDEEP
javascriptjquery
Pritam
Pritam

Reputation: 3

prevent all characters and symbols if the first character is not # in jquery or javascript

I was trying to prevent all characters and symbols if the first character is not #(hash) in jquery or javascript.

This is what I have tried, but keyup did not work.

<input data-role="tagsinput" type='text' placeholder="Enter search tags..." id="searchtag"> 

$("#searchtag input").keyup(function () {
     if ($(this).val().length >= 1){
        if ($(this).val() !== "#"){
            $(this).val('');
        }
     }
 });

Upvotes: 0

Views: 37

Answers (2)

Shahar
Shahar

Reputation: 2191

One option is to prevent every event on key down, therefore the event will not register and you will not need to remove a character that has been added.

NOTE: The if statement can be simplified, written this way for clarity purposes.

Try to run the following snippet: 

const input = document.getElementById('searchtag');
input.addEventListener('keydown', function(e) {
  if (e.key === '#' && this.value.length === 0) {
    // Do nothing
  } else if (this.value.length > 0 && this.value[0] === '#') {
    // Do nothing
  } else {
    e.preventDefault();
  }
});
<input type="text" id="searchtag">

Upvotes: 2

Praveen Kumar Purushothaman
Praveen Kumar Purushothaman

Reputation: 167202

Your selector is wrong. The input should come in front or shouldn't come. Use either of it:

$("input#searchtag").keyup(function() {
  if ($(this).val().length >= 1) {
    if ($(this).val() !== "#") {
      $(this).val('');
    }
  }
});

$("#searchtag").keyup(function() {
  if ($(this).val().length >= 1) {
    if ($(this).val() !== "#") {
      $(this).val('');
    }
  }
});

When you give a space and input, it will try to look for the child input under the element with id #searchtag.

Upvotes: 0

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