Web Storage QuotaExceededError

When storage limits exceeds on this function window.sessionStorage.setItem(key, value);, it throws a "QuotaExceededError" DOMException exception if the new value couldn't be set. (Setting could fail if, e.g., the user has disabled storage for the site, or if the quota has been exceeded.)

by Yashwanth M

HTML

<button type="button" id="fill-button">Fill sessionStorage</button><br>
<button type="button" id="clear-button">Clear sessionStorage</button>

JavaScript

/* global window, document */
var exampleString = 'Let\'s save a string into many different storage items, until the storage quote is exceeded.',
counter = 0,
/** tries to write a value into a sessionStorage key. Alerts any error */
writeString = function (key, value) {
    try {
        window.sessionStorage.setItem(key, value);
    } catch (error) {
        window.alert(error);
        return false;
    }
    return true;
},
fillButtonClickHandler = function () {
    /** increase the key number for sessionStorage, until writeStringHandler returns false */
    while (writeString('key_' + counter, exampleString)) {
        counter += 1;
    }
},
clearButtonClickHandler = function () {
    window.sessionStorage.clear();
    counter = 0;
};

document.getElementById('fill-button').addEventListener('click', fillButtonClickHandler);
document.getElementById('clear-button').addEventListener('click', clearButtonClickHandler);