Inside component.ts:
var bannerContent = `<div>
Created = ${item.created_at | date}
</div>`;
Throws error on console: 'date is not defined.'
Following is also not working and prints as this as it is (without evaluating)
var bannerContent = `<div>
Created = {{item.created_at | date}}
</div>`;
Update: Usage of this variable is like:
marker.addListener('click', function() {
var infowindow = new google.maps.InfoWindow({content: bannerContent});
...
...
});