User:SD0001/dark-mode-toggle.js

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This user script seems to have a documentation page at User:SD0001/dark-mode-toggle.

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/**
 * Enables or disables the dark mode gadget.
 */

$.when($.ready, mw.loader.using(['mediawiki.util', 'mediawiki.api'])).then(function() {
    var inDarkMode = !!mw.user.options.get('gadget-dark-mode');

    var linkText = inDarkMode ? 'Light mode' : 'Dark mode';

    mw.util.addPortletLink('p-cactions', '#', linkText, 'pt-darkmode', inDarkMode ? 'Turn off dark mode' : 'Turn on dark mode', 'np');

    $('#pt-darkmode').on('click', function(e) {
        e.preventDefault();
        mw.notify(inDarkMode ? 'Disabling dark mode ...' : 'Enabling dark mode ...');
        new mw.Api().saveOption('gadget-dark-mode', inDarkMode ? '0' : '1').then(function() { 
            location.reload(); 
        });
    });
});