Can I insert elements to the beginning of an element using .appendChild()?

Question

If the user selects an option in a dropdown box, there must be added a label and a textbox. Using appendChild , these elements get added to the end of the container .

var newFreeformLabel = document.createElement('label');
newFreeformLabel.innerHTML = 'Omschrijving:';

var newFreeformField = document.createElement('input');
newFreeformField.className = 'textfield';
newFreeformField.name = 'factuur_orderregel[]';

var newFreeformSpacer = document.createElement('div');
newFreeformSpacer.className = 'spacer';

container.appendChild(newFreeformLabel);
container.appendChild(newFreeformField);
container.appendChild(newFreeformSpacer);

The issue is that these elements should be inserted at the beginning of container , not at the end.

Is there a solution to this in PrototypeJS?

Answer 1

As well as appendChild , DOM nodes have an insertBefore method

container.insertBefore(newFreeformLabel, container.firstChild);

Answer 2

Modern Solution

To add a child to the beginning of a parent, use prepend

parent.prepend(newChild)

To add at the end of a parent, use append

parent.append(newChild)

In addition, if you want to add relative to another child, use one of these:

child1.after(newChild)  // [child1, newChild, child2]

child1.before(newChild) // [newChild, child1, child2]

Advanced usage

1. You can pass multiple values (or use spread operator ... ).
2. Any string value will be added as a text element.

Examples:

parent.prepend(newChild, "foo")  // [newChild, "foo", child1, child2]

const list = ["bar", newChild]
parent.append(...list, "fizz")  // [child1, child2, "bar", newChild, "fizz"]

Related DOM method - child.replaceWith

Documentation

Can I Use

Answer 3

UseElement.insert(element, content) .

Answer 4

container.
    insert({
        // key is position
        // 'before', 'after', 'top' and 'bottom' are allowed
        top: new Element('label').
            update('Omschrijving:')
    }).
    insert({
        top: new Element('input').
            addClassName('textfield').
            writeAttribute('name', 'factuur_orderregel[]')
    }).
    insert({
        top: new Element('div').
            addClassName('spacer')
    });

I think Prototype's Element.insert is somewhat awkward for before / after , however. For instance, if you wanted to place the .spacer before the .textfield , sometime later in your code, you would need to do something like:

container.
    down('.textfield').
    insert({
        before: new Element('div').
            addClassName('spacer')
    });

This is, especially if you're familiar with the DOM API's Element.insertBefore , somewhat unintuitive, as you are not inserting the .spacer into the .textfield , but instead into the container , before the .textfield .

Answer 5

If I had seen Gareth's solution on time, I might go with that, as it was I used:

$('toggle_product').innerHTML = insertContent + $('toggle_product').innerHTML;

as Prototypes' insert() function was returning error in IE8..