CODEWITHSUNDEEP
javascriptjqueryhtmlcss
JavaUser
JavaUser

Reputation: 26324

jquery - remove class based on condition

I am polling a json response for every 1 min and based on the response I am adding or removing overlay on my page. My response is most of the time positive , in this case , i should remove the overlay class. In the below code, else part is executing every time and remove class and hide functions are executed every time. Is there any way to avoid this . Is there any method in jquery to check whether class is added or not . Also hide is active or not. Or can anyone give syntax to achieve this by setting and unsetting a boolean variable.

(function poll() {
  setTimeout(function() {
    $.ajax({
      url: "path",
      type: "GET",
      success: function(data) {
        console.log("polling" + data);
        if (data.is_running === true) {
          $("#overlay").addClass('show');
          $("#alertDiv").show();
        } else {
          console.log("removing ....");
          $("#overlay").removeClass('show');
          $("#alertDiv").hide();

        }
      },
      dataType: "json",
      complete: poll,
      timeout: 200
    })
  }, 5000);
})();

Upvotes: 8

Views: 4468

Answers (4)

cfischer
cfischer

Reputation: 470

You can check if an element has a specific class with hasclass():

var overlay = $('#overlay');

if (overlay.hasClass('show')) {
  overlay.removeClass('show');
}

But you can use toggle() and toggleClass(), see Pranav's answer.

Upvotes: 3

Venkat.R
Venkat.R

Reputation: 7736

Try like below and keep the $() query methods in variable to make efficient !

var $overLay = $("#overlay"),
    $alertDiv = $("#alertDiv"),
    sh = 'show';

 if (data.is_running === true) {
   $overLay.addClass();
   $alertDiv.show(sh);
 } else if ($overLay.hasClass(sh)) {
   $overLay.removeClass(sh );
   $alertDiv.hide();
 }

Upvotes: 4

Ali Khan
Ali Khan

Reputation: 108

I think you are getting data.is_running as "true"

Please change your code like this

if (data.is_running == true){
   //your code
}
or 
if (data.is_running == "true"){
   //your code
}

Upvotes: 0

Pranav C Balan
Pranav C Balan

Reputation: 115212

You can use toggle() and toggleClass() with Boolean value no need of if...else statement otherwise returns false

$("#overlay").toggleClass('show',data.is_running);
$("#alertDiv").toggle(data.is_running);

And for checking that an element has a class or not you can use hasClass() which returns true if matched elements are assigned the given class

Upvotes: 13

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