dom-if template does not work

Question

dom-if template does not work. I have the following polymer 2 component:

<link rel="import" href="../bower_components/polymer/polymer-element.html">

<dom-module id="ohr-block">
    <template>
        <style>
            :host {
                display: block;
            }
        </style>
        <h3>[[mydata.title]] [[_isType('one')]]</h3>
        <template is="dom-if" if="[[_isType('one')]]"> <!-- problem is here -->
            <div>Should be displayed</div>
        </template>
    </template>

    <script>
        /**
        * @customElement
        * @polymer
        */
        class OhrBlock extends Polymer.Element {
            static get is() { return 'ohr-block'; }

            static get properties() {
                return {
                    mydata: {
                        type: Object,
                        value: {"title": "my title", "type" : "one"}
                    }
                };
            }

            _isType(type) {
                return this.mydata.type === type;
            }
        }

        window.customElements.define(OhrBlock.is, OhrBlock);
    </script>
</dom-module>

As you can see, I am using [[_isType('one')]] inside h3 html tag. In this place it is working and I can see true but when I use [[_isType('one')]] like condition into if attribute it does not work and template content is not showed.

Answer 1

The problem is I have not imported dom-if

<link rel="import" href="../bower_components/polymer/lib/elements/dom-if.html">