Stop setInterval

Core tips for interval management

• Store the setInterval return value in a variable, typically named intervalId or similar, for future reference.
• Invoke clearInterval from a scope that lets you access the interval ID.
• For AJAX requests, use clearInterval inside both success and error callbacks. This strategy ensures the interval state is handled, no matter what happens with your AJAX call.

Juggling errors and intervals

Your setInterval must not continue after an error occurs. Here's how to handle it:

let intervalId;
  
function ohNoItsAnError(error) {
  clearInterval(intervalId); // STOP! Hammertime
  console.error("Update failed", error); // Drop a log
  alert("The AJAX elves stumbled. Interval stopped. Try refresh!"); // Huh, who's there?
}

// Function to make AJAX call
function updateDiv() {
  $.ajax({
    url: "send/to-this-url",
    success: function(data) {
      // overwrite the div here 
    },
    error: ohNoItsAnError
  });
}
  
// Starting interval when the document is ready
$(document).ready(function() {
  intervalId = setInterval(updateDiv, 3000); // every 3 seconds, like clockwork
});
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With this pattern, updates stop when there's an error, saving you unnecessary network traffic. Plus, the user gets informed about the issue.

Clean interval management through encapsulation

To ensure a clean management of setInterval, encapsulate the clearInterval operation in a separate function:

function stopInterval(intervalId) {
  clearInterval(intervalId);
  console.log("Interval stopped! Enough hopping for today."); // Here lies the end of interval hopping
}
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Call your function immediately before setting it to repeat with setInterval. This approach ensures the function runs once instantly, preventing the initial delay equal to the interval's duration:

updateDiv(); // Immediately called
intervalId = setInterval(updateDiv, 3000); // Set to repeat
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For the setInterval to be stopped from any part of your script, make sure the interval variable is defined in the globally accessible scope:

var intervalId; // Defined globally at the top of the script
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Going the extra mile: Power Tips

Beyond basic interval control, these smart strategies offer better control and efficiency:

A return false safety net

After clearInterval, using return false can halt following actions in your event handlers or similar constructs. It's like the emergency stop button.

Double-check with clearInterval

Check to ensure clearInterval was invoked, and the interval has indeed halted:

let intervalId;
let isActive = true;

clearInterval(intervalId);
intervalId = null;

isActive = false; // Pro-tip: this flag!
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The isActive flag helps to keep track of the interval status and confirm that it's stopped, helping you swat bugs before they manage to do a number on your script.

Alternatives are your friend

For high precision tasks or animations, consider requestAnimationFrame as a more advanced alternative to setInterval. It can lend your script a smoother and more performant demeanor.