Question

In jQuery, you can run a selector where every element is run through a function you define, like this (totally contrived example):

jQuery.expr[':'].AllOrNothing= function(a,i,m){
    // a is the thing to match, m[3] is the input
    if(m[3] === "true"){
      return true;
    } else {
      return false;
    }
  };

Then you can use it like:

$("div:AllOrNothing(" + true + ")"); //returns all divs
$("div:AllOrNothing(" + false + ")"); //returns nothing

Is it possible to pass an anonymous function instead of calling jQuery.expr[:].Name= ?

Edit

I’m envisioning something chainable like the following:

$("div").filterByFunction(function(a,i,m){ ... })

Answer 1

It sounds like you just want to use the built-in .filter() method and pass it a custom function that examines sibling elements to decide whether to return true or false and then hide the remaining elements.

$("section").filter(function() {
    // examine child div and return true or false
}).hide();