How to close POI's InfoWindow? - google-maps-api-3

Question

I'm trying to make POI's InfoWindow close when click a link.
I overrided the setContent of InfoWindow like this:
//override the built-in setContent-method
google.maps.InfoWindow.prototype.setContent = function (content) {
content = content.innerHTML + '<br/> Save place';
//run the original setContent-method
fx.apply(this, arguments);
};
Note: I didn't create any InfoWindow object to reference to use close() method.

Answer 1

In your override function capture a global reference to the infowindow so you can reference it to close it.
Your override of the infowindow doesn't work. I took a working version from this question: How to get a click event when a user clicks a (business) place on the map
proof of concept fiddle
code snippet:
var geocoder;
var map;
var infowindow;
//keep a reference to the original setPosition-function
var fx = google.maps.InfoWindow.prototype.setPosition;
// from https://stackoverflow.com/questions/24234106/how-to-get-a-click-event-when-a-user-clicks-a-business-place-on-the-map/24234818#24234818
//override the built-in setPosition-method
google.maps.InfoWindow.prototype.setPosition = function() {
//logAsInternal isn't documented, but as it seems
//it's only defined for InfoWindows opened on POI's
if (this.logAsInternal) {
// save reference in global infowindow variable.
infowindow = this;
google.maps.event.addListenerOnce(this, 'map_changed', function() {
var map = this.getMap();
//the infoWindow will be opened, usually after a click on a POI
if (map) {
//trigger the click
google.maps.event.trigger(map, 'click', {
latLng: this.getPosition()
});
}
});
}
//call the original setPosition-method
fx.apply(this, arguments);
};
function initialize() {
var map = new google.maps.Map(
document.getElementById("map_canvas"), {
center: new google.maps.LatLng(37.4419, -122.1419),
zoom: 13,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
google.maps.event.addDomListener(document.getElementById('btn'), 'click', function(e) {
// close the last opened POI infowindow
infowindow.close();
});
}
google.maps.event.addDomListener(window, "load", initialize);
html,
body,
#map_canvas {
height: 100%;
width: 100%;
margin: 0px;
padding: 0px
}
<script src="https://maps.googleapis.com/maps/api/js"></script>
<input id="btn" type="button" value="close IW" />
<div id="map_canvas"></div>