basic_widget.js

(function() {

var getJSON = function(options, callback) {
    var xhttp = new XMLHttpRequest();
    options.url = options.url || location.href;
    options.data = options.data || null;
    callback = callback ||  function() {};
    options.type = options.type || 'json';
    var url = options.url;
    xhttp.open('GET', options.url, true);
    xhttp.send(options.data);
    xhttp.onreadystatechange = function() {
        if (xhttp.status == 200 && xhttp.readyState == 4) {
            callback(xhttp.responseText);
        }
    };
};

function insertAfter(referenceNode, newNode) {
    referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);
}

var callback = function(data) {
    data = eval('('+data+')');
    console.log(data);
    $ref_node = document.querySelector('.article_meta');
    stat = document.createElement('div');
    stat.id = 'stat_ui';
    widget_content = '<h3>Analytics</h3><div id="ui_content"></div>';
    stat.innerHTML = widget_content;
    insertAfter($ref_node, stat);
    $ui_content = document.querySelector('#ui_content');
    $ui_content.innerHTML = '<div><h4>Today</h4><p>Pageviews: <strong>' + data.today.total + '</strong></p></div>';
    //$btc_system.innerHTML = content;

};
var api = 'http://host.com/api/post'
getJSON({'url': api+'?url=' + location.href}, callback);

})();