Select elements that i have previously set with jquery.data();
i.e. Select all elements with .data('myAttr')
already been set.
SOLUTION
A jsfiddle to demostrate is Fiddle
You could do
$('[data-myAttr!=""]');
this selects all elements which have an attribute data-myAttr
which is not equal to '' (so it must have been set);
you could also use filter()
$('*').filter(function() {
return $(this).data('myAttr') !== undefined;
});