ElementObserver

A MutationObserver inspired observer for Custom Elements like mutations on any DOM element.

``js
import ElementObserver from '@webreflection/element-observer';

const observer = new ElementObserver({
// optional, used only if options for attributes are used
attributeChangedCallback(element, name, oldValue, newValue) {
// all observed attributes will be triggered right away if present,
// when the element is observed, and before connectedCallback,
// as it is for Custom Elements
},

// optional, used when the element is connected
connectedCallback(element) {
// if the element is already connected when observed, this is triggered.
},

// optional, used when the element is disconnected
disconnectedCallback(element) {}
});

observer.observe(
observedElement,
// optional, if present is used to define attributes
{
// optional, if omitted will observe all attributes
attributeFilter: ['only', 'these'],
// optional, if omitted oldValue is always null
attributeOldValue: true,
// optional, if any of the previous properties are defined,
// this is implicitly set as true
attributes: true
}
);

observer.disconnect(
// optional, if an element is passed, only that element
// stops being observed, otherwise all observed elements
// will immediately stop being observed
observedElement
);
``

See MutationObserver.observe() to better understand attributes properties.