leandroz

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Element

Box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
• elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
• elem.getClientRects(), elem.getBoundingClientRect()

leandroz

// Three mostly separate examples: Adding, reading/listening, and removing multiple items from firebase
// Firebase V3.0.0
// one school has many courses and many studens
// one course has many students and is in only one school
// one student is in many courses and only one school

const db = firebase.database().ref('test');
const userId = firebase.auth().currentUser.uid;

/*  --  ADDING  --  */