markdown-live-preview/public/js/main.js

$(function() {
    let isEdited = false;

    let adjustScreen = () => {
        let screenHeight = $(window).height();
        let headerHeight = $('#header').outerHeight();
        let footerHeight = $('#footer').outerHeight();
        let containerHeight = screenHeight - headerHeight - footerHeight;
        $('#container').css({ top: `${headerHeight}px` });
        $('.column').css({ height: `${containerHeight}px`});
    };

    $(window).resize(() => {
        adjustScreen();
    });

    // Setup editor
    let editor = ace.edit('editor');
    editor.getSession().setUseWrapMode(true);
    editor.renderer.setScrollMargin(10, 10, 10, 10);
    editor.setOptions({
        maxLines: Infinity,
        indentedSoftWrap: false,
        fontSize: 14,
        autoScrollEditorIntoView: true,
        theme: 'ace/theme/github',
        // TODO consider some options
    });
    editor.on('change', () => {
        isEdited = true;
        convert();
        adjustScreen();
    });

    let convert = () => {
        let html = marked(editor.getValue());
        let sanitized = DOMPurify.sanitize(html);
        $('#output').html(sanitized);
    }
    
    //leave
    $(window).bind('beforeunload', function() {
      if (isEdited) {
        return 'Are you sure you want to leave? Your changes will be lost.';
      }
    });

    convert();
    adjustScreen();
});