title: JSTree - Load nodes dynamically
body: <p>I'm using jstree v.3. 
  I have a working example, where all the data is downloaded once from the server side via ajax. </p>
  
  <pre><code>$('#tree').jstree({
              'core': {
                  'data': {
                      'url': "/ajax/getAll",                           
                      'data': function(node) {
                          return {'id': node.id};
                      },
                      // "check_callback" : true                    
                  }
              },
              "types": {
                  "category": {
                      "icon": "/img/category.png"
                  },
                  "page": {
                      "icon": "/img/page.png"
                  }
              },
              "plugins" : ["types"]
  
          });
  </code></pre>
  
  <p>But I have <strong>A LOT</strong> of data to present. I want to load data for items, that were clicked. I don't have problems with server side, but I can't find examples for jstree part. Can anybody share the code or give advise?</p>