getData.js

/**
 * Created by Herbert on 25.01.2016.
 *
 * Open webpage https://en.wikipedia.org/wiki/List_of_state_leaders_in_2015 with disabled images (for better performance),
 * copy-paste this script to browser console, after about 600 seconds, all parsed names and birth dates should be stored
 * in global variable allBorn
 */
var $selector=$("#mw-content-text > ul > li > ul > li > a:nth-child(1)," + "#mw-content-text > ul > li > ul > li > ul > li > a:nth-child(1)," + "#mw-content-text > ul > li > ul > li > ol > li> a:nth-child(1)"),
    bornSelector="tr:has(th:contains('Born')) td";

var win = document.defaultView || this.ownerDocument.parentWindow, repeat=true,repeated=false,allBorn="",i=0;
$selector.each(function(){
    var $a=$(this);
    setTimeout(function() {
        if(!repeat&&repeated){
            return;
        }else{
            repeated=true;
        }

            var url="https://en.wikipedia.org"+$a.attr("href");
            if (win == window) {
                var $newWindow=$("<iframe></iframe>");

                $newWindow.appendTo('body');$newWindow.css({
                    'position':'fixed',
                    'width':'100%',
                    'height':'700px',
                    'top':0,
                    'left':0,
                    'z-index':100+(i)
                });
                $newWindow[0].contentWindow.location.href=url;
                $newWindow.on('load',function(){
                    var $contents=$newWindow.contents();
                    var $bornRef=$contents.find(bornSelector);
                    var $bDay=($bornRef.length!=0)?$bornRef.find(".bday"):[];
                    var $born=($bDay.length!=0)?$bDay.text():[];
                    var $name=$contents.find("#firstHeading").text();
                    if($born.length<128 && $born.length>0){
                        allBorn+=$name+"::"+$born+";;;;";
                    }

                    $newWindow.unbind('load');
                    $newWindow.remove();
                });
            }
    }, (i++)*1000);

});
setTimeout(function() {console.log(allBorn)},6000);
setTimeout(function() {console.log(allBorn)},40000);
setTimeout(function() {console.log(allBorn)},(i)*1000);