Click a button and copy the content

README.md

Introduction

Click a button and copy the assigned textarea or input's content to clipboard.

Html

<input type="text" id="copy_target" value="Text to Copy">
<button id="copy_button">Copy</button>

Javascript

document.getElementById("copy_button").addEventListener("click", function() {
    copyToClipboard(document.getElementById("copy_target"));
});

function copyToClipboard(elem) {
    // Create hidden text element, if it doesn't already exist.
    var targetId = "_hiddenCopyText_";
    var isInput = elem.tagName === "INPUT" || elem.tagName === "TEXTAREA";
    var origSelectionStart, origSelectionEnd;
    if (isInput) {
        // Can just use the original source element for the selection and copy.
        target = elem;
        origSelectionStart = elem.selectionStart;
        origSelectionEnd = elem.selectionEnd;
    } else {
        // Must use a temporary form element for the selection and copy.
        target = document.getElementById(targetId);
        if (!target) {
            var target = document.createElement("textarea");
            target.style.position = "absolute";
            target.style.left = "-9999px";
            target.style.top = "0";
            target.id = targetId;
            document.body.appendChild(target);
        }
        target.textContent = elem.textContent;
    }
    // Select the content.
    var currentFocus = document.activeElement;
    target.focus();
    target.setSelectionRange(0, target.value.length);

    // Copy the selection.
    var succeed;
    try {
        succeed = document.execCommand("copy");
    } catch(e) {
        succeed = false;
    }
    // Restore original focus.
    if (currentFocus && typeof currentFocus.focus === "function") {
        currentFocus.focus();
    }

    if (isInput) {
        // Restore prior selection.
        elem.setSelectionRange(origSelectionStart, origSelectionEnd);
    } else {
        // Clear temporary content.
        target.textContent = "";
    }
    return succeed;
}