JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" ng-model="name" placeholder="Enter Name">

CSS

input {
    padding: 10px;
}

JavaScript

function getSelectionHtml() {
    var input = document.getElementsByTagName('input')[0];
    var selectedText = input.value.substring(input.selectionStart, input.selectionEnd);
    if (selectedText) {
        alert(selectedText);
    }
}

document.getElementsByTagName('input')[0].onmouseup = getSelectionHtml;