Let .hasEvent work with array iteration methods.

[ryanve]

This simple change lets .hasEvent(event, element?) work with methods like array.every or array.filter. It checks if element is a number and if so it uses this as the element.

['drag', 'dragend'].every(Modernizr.hasEvent) // uses 'div' in strict mode, `window` in non-strict
['drag', 'dragend'].every(Modernizr.hasEvent, 'img') // creates element on each iteration
['drag', 'dragend'].every(Modernizr.hasEvent, document.createElement('img')) // reuses element

Explicitly supplying the thisArg avoids the strict mode difference.

[stucox]

Hi Ryan, sorry it’s taken a while to get to this – looks good.

I don’t get why there’s a difference between strict mode / non-strict mode though? My knowledge of the details of strict mode is embarrassingly lacking though, tbh.

[ryanve]

I accounted for both modes in case 'use strict'; was ever added here or in an outer closure.

strict mode

• No boxing occurs. thisArg values resolve exactly. this defaults to undefined

unstrict mode

• this resolves to window when thisArg is undefined or null
• Primitive thisArg values get boxed into the "object" type. .valueOf() unboxes them (if primitive) but throws if used on undefined|null|Object.create(null)

[ryanve]

Consider these variants:

1. 100% consistent between strict and unstrict mode:

   if ( typeof element === 'number' ) element = null == this ? window : this.valueOf();

2. Throws error in strict mode if this == null but is consistent between modes for other cases:

   if ( typeof element === 'number' ) element = this.valueOf();

3. Needs another check to make tagnames work in unstrict mode and the default varies by mode:

   if ( typeof element === 'number' ) element = this;
   if ( element instanceof String ) element = '' + element;

[ryanve]

Consider the docs, and keeping them simple. .hasEvent can be used with array methods by passing an element or tagname as the thisArg. Then show examples. Questions to answer are:

• Should we add the syntax at all? (It's not needed, but it helps write terse code)
• Should it support tagnames? (If no then the first line of variant 3 would suffice)
• Should it worry about strict mode? (I like variant 1 if yes, and my original or 2 if no)