JSFiddle - React, Tailwind, and code Playground

by Louis Lazaris

HTML

<p>Code explanation: <a href="http://www.impressivewebs.com/textarea-auto-resize/">Textarea Auto Resize</a></p>

<textarea id="comments" placeholder="Type many lines of texts in here and you will see magic stuff" class="common"></textarea>

CSS

body {
     margin: 20px;
}

p {
    margin-bottom: 14px;
}

textarea {
    color: #444;
    padding: 5px;
}

.txtstuff {
    resize: none; /* remove this if you want the user to be able to resize it in modern browsers */
    overflow: hidden;
}

.hiddendiv {
    display: none;
    white-space: pre-wrap;
    word-wrap: break-word;
    overflow-wrap: break-word; /* future version of deprecated 'word-wrap' */
}

/* the styles for 'commmon' are applied to both the textarea and the hidden clone */
/* these must be the same for both */
.common {
    width: 500px;
    min-height: 50px;
    font-family: Arial, sans-serif;
    font-size: 13px;
    overflow: hidden;
}

.lbr {
    line-height: 3px;
}

JavaScript

/*global document:false, $:false */
var txt = $('#comments'),
    hiddenDiv = $(document.createElement('div')),
    content = null;

txt.addClass('txtstuff');
hiddenDiv.addClass('hiddendiv common');

$('body').append(hiddenDiv);

txt.on('input', function () {

    content = $(this).val();

    content = content.replace(/\n/g, '<br>');
    hiddenDiv.html(content + '<br class="lbr">');

    $(this).css('height', hiddenDiv.height());

});

txt.trigger('input');