Angular bind to filtered count <p>I have this array:</p> <pre><code>[ { type: "hhh", items: [ { "name": "EGFR", "type": "a", "selected": true } ] }, { type: "aaa", items: [ { "name": "mm", "type": "b", "selected": false } ] }, { type: "ii", items: [ { "name": "pp", "type": "bb", "selected": true } ] } ] </code></pre> <p>I want to show a counter of the items with selected property "true". I want it to be changed real time when change. (Without watch and function)</p> <p>Thnaks!</p>