document.querySelector.bind("document")

Making a short alias for document.querySelectorAll

I'm going to be running document.querySelectorAll() a whole lot, and would like a shorthand alias for it.

  var queryAll = document.querySelectorAll
  queryAll('body')
  
  TypeError: Illegal invocation

Doesn't work. Whereas:

  document.querySelectorAll('body')

Still does. How can I make the alias work?

Answer:

This seems to work:

var queryAll = document.querySelectorAll.bind(document);

bind returns a reference to the querySelectorAll function, changing the context of 'this' inside the querySelectorAll method to be the document object.

The bind function is only supported in IE9+ (and all the other browsers) -https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Function/bind


Update: In fact you could create shortcuts to a whole range of document methods like this:

var query = document.querySelector.bind(document);
var queryAll = document.querySelectorAll.bind(document);
var fromId = document.getElementById.bind(document);
var fromClass = document.getElementsByClassName.bind(document);
var fromTag = document.getElementsByTagName.bind(document);


http://stackoverflow.com/questions/13383886/making-a-short-alias-for-document-queryselectorall
http://stackoverflow.com/questions/14251357/what-is-the-meaning-of-document-queryselector-binddocument
原文地址:https://www.cnblogs.com/rhett-web/p/4953370.html