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Re: What's wrong with using a global id?

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Thomas 'PointedEars' Lahn wrote:

> By having an element with ID “null” inserted and parsed in the HTML
> document, the global object provides access to the object representing
> that element in the document tree (an “element object” implementing the
> Element interface of W3C DOM 4, through an element-type specific interface
> – here, the HTMLParagraphElement interface) via property access to a
> property named “null”.
> 
> Note that this wording, although more complicated, is important: it does
> _not_ imply that the global object actually has a property with that name.
> And indeed, using Object.getOwnPropertyNames(this).indexOf("null") in
> Firefox 52 (navigator.userAgent === "Mozilla/5.0 (X11; Linux x86_64;
> rv:52.0) Gecko/20100101 Firefox/52.0") one can show that it does not, and
> neither has one of the objects in its prototype chain
> (“Object.getPrototypeOf(this)” aso.)

One can now (ES 2015+) construct such an object using Proxy:

  var proxy = new Proxy({
    Array: Array
  }, {
    get: function (target, name) {
      return (name in target)
        ? target[name]
        : document.getElementById(name);
    }
  });

  /* “[object Array]” (in all cases) */
  console.log(proxy.Array);

  /* “[object HTMLParagraphElement]” (in this case) */
  console.log(proxy.null);

-- 
PointedEars
FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
<https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.

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Re: What's wrong with using a global id? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-02-26 14:30 +0100
  Re: What's wrong with using a global id? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-02-26 14:35 +0100
    Re: What's wrong with using a global id? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-02 15:05 +0100
  Re: What's wrong with using a global id? John G Harris <niam@jghnorth.org.uk.invalid> - 2018-02-26 20:11 +0000

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