paper-autocomplete validation is not working - validation

Question

I'm working on polymer based front-end project. I'm pretty new at this kind of stuff and I'm struggling finding info and working examples of components I need. I know there is demo showcases of those components but they don't give me what I need.
<iron-form id="formForm">
<form>
<paper-autocomplete label="Country" required error-message="This field is required"></paper-autocomplete>
</form>
</iron-form>
When I use paper-autocomplete element inside <iron-form>, and add required attribute to it, <iron-form> calls paper-autocomplete validator. But when I create my own polymer element which has only paper-autocomplete included, iron form doesn't see it when I include it inside.
There is my custom polymer element
<link rel="import" href="../../../bower_components/polymer/polymer.html">
<link rel="import" href="../../../bower_components/iron-ajax/iron-ajax.html">
<link rel="import" href="../../../bower_components/paper-autocomplete/paper-autocomplete.html">
<link rel="import" href="../globals-behavior.html">
<dom-module id="autocomplete-country">
<template>
<iron-ajax id="countryFindCall"
url="{{restUri}}/classifier/country/find"
params="{{query}}"
on-response="handleResponse"
debounce-duration="300"></iron-ajax>
<paper-autocomplete label="Country" id="country-autocomplete" remote-source="true" min-length="2"
text-property="label" value-property="value" disable-show-clear="true"></paper-autocomplete>
</template>
<script>
Polymer({
is: "autocomplete-country",
behaviors: [
GlobalsBehavior
],
properties: {
item: {
notify: true
},
query: {
type: Object
},
result: {
type: Object
},
selected: {
type: Object,
value: {}
}
},
attached: function() {...},
handleResponse: function (data) {...},
onSelect: function(event) {...},
onChange: function(event) {...},
onBlur: function() {...}
});
</script>
</dom-module>
And this is how I'm including it
<iron-form id="formForm">
<form>
<autocomplete-country item="{{request.country}}" required error-message="Field is required"></autocomplete-country>
</form>
</iron-form>

Answer 1

Taken from the iron-form documentation:
<iron-form> is an HTML <form> element that can validate and submit any custom elements that implement Polymer.IronFormElementBehavior.
So I guess your element should implement that and you´re good to go.

Answer 2

Solved this problem by adding new parameter required and adding it as attribute :
<paper-autocomplete ... required$="[[required]]" ... ></paper-autocomplete>