The insertAdjacentElement() method of the Element interface inserts a given element node at a given position relative to the element it is invoked upon.

position

A string representing the position relative to the targetElement; must match (case-insensitively) one of the following strings:

• 'beforebegin': Before the targetElement itself.
• 'afterbegin': Just inside the targetElement, before its first child.
• 'beforeend': Just inside the targetElement, after its last child.
• 'afterend': After the targetElement itself.

element

The element to be inserted into the tree.

The element that was inserted, or null, if the insertion failed.

• SyntaxError DOMException
  • Thrown if the position specified is not a recognized value.
• TypeError
  • Thrown if the element specified is not a valid element.

beforeBtn.addEventListener("click", () => {
  const tempDiv = document.createElement("div");
  tempDiv.style.backgroundColor = randomColor();
  if (activeElem) {
    activeElem.insertAdjacentElement("beforebegin", tempDiv);
  }
  setListener(tempDiv);
});

afterBtn.addEventListener("click", () => {
  const tempDiv = document.createElement("div");
  tempDiv.style.backgroundColor = randomColor();
  if (activeElem) {
    activeElem.insertAdjacentElement("afterend", tempDiv);
  }
  setListener(tempDiv);
});

Have a look at our insertAdjacentElement.html demo on GitHub (see the source code too.) Here, we have a sequence of <div> elements inside a container. When one is clicked, it becomes selected and you can then press the Insert before and Insert after buttons to insert new divs before or after the selected element using insertAdjacentElement().

• Element.insertAdjacentHTML()
• Element.insertAdjacentText()
• Node.insertBefore() (similar to beforebegin, with different arguments)
• Node.appendChild() (same effect as beforeend)