Why is colspan not a known native attribute in Angular 2?

Question

If we attempt code like this:

Column

or this:

Colu         


        

Answer 1

**Similar example

Property and attribute aren't always 1:1. An often encountered example is the label tag

In Angular

fails with the same error and you'd need to bind like

or

but

would also work because in this case htmlFor is the property that is reflected to the DOM for attribute. See also https://developer.mozilla.org/de/docs/Web/API/HTMLLabelElement for the htmlFor property (in the Properties section)

See also What is the difference between attribute and property?

colSpan the actual property name

According to https://developer.mozilla.org/en-US/docs/Web/API/HTMLTableCellElement colSpan is the property that is reflected to the colspan attribute therefore (uppercase S)

Column

See also https://plnkr.co/edit/BZelYOraELdprw5GMKPr?p=preview

works just fine.

Why does Angular bind to properties by default

Angular binds to the property by default for performance reasons. Binding to an attribute is expensive because attributes are reflected in the DOM and a change in the DOM can causes reevaluation of CSS styles that might match after the change, while properties are just a value in a JavaScript object that changed.
With attr. you opt in explicitely to the expensive behavior.