The data items displayed by vaadin-combo-box can be set and accessed using the
items property. The items may be assigned with data-binding, using an attribute or the
JavaScript property directly. An array of String or Object values is currently supported.
Use the label attribute to provide a label for the element.
Typing some text into the vaadin-combo-box's input field will filter
the values defined in the items property and show only items that
contain the value in the input field. If the typed value doesn't
match any of shown items, closing the vaadin-combo-box will select the typed value.
HTMLImports.whenReady(function() {
// code
var combobox = combobox || document.querySelector('vaadin-combo-box');
// The elements is an array of String values.
combobox.items = elements;
// end-code
});