# MapView MarkerTapped updating Observables

**URL:** <https://forums.fusetools.com/t/mapview-markertapped-updating-observables/527>\
**Category:** How-to Discussions\
**Created:** [March 14, 2017, 3:20pm UTC](https://forums.fusetools.com/t/mapview-markertapped-updating-observables/527 "2017-03-14T15:20:10Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![paul](https://avatars.discourse-cdn.com/v4/letter/p/bbe5ce/32.png) [@paul](https://forums.fusetools.com/u/paul)\
**Post date:** [March 14, 2017, 3:20pm UTC](https://forums.fusetools.com/t/mapview-markertapped-updating-observables/527/1 "2017-03-14T15:20:10Z")

</div>

I have a problem with MapView MarkerTapped,

```auto
var contact = Observable("");
var contactInfo = Observable(
  {Latitude:59.913580, Longitude:10.731637, Label:"Klingenberggata 7"},
  {Latitude:59.920814, Longitude:10.683548, Label:"Sjølyst / Karenlyst Allé 9"},
  {Latitude:59.912191, Longitude:10.742993, Label:"Steen og Strøm Magasin"},
  {Latitude:59.910617, Longitude:10.728045, Label:"Aker Brygge / Grundingen 1"},
  {Latitude:59.916261, Longitude:10.714986, Label:"Frognerveien 8"});

  function updateInfo(arg){
    contact.clear();
    contact.add(arg);
    console.log("1." + arg.Label);
  }

```

Then trying to use updateInfo to display the label beneath the mapview:

```auto
    <NativeViewHost ux:Name="mapy" Alignment="Left" Width="100%">
      
      <MapView Height="450" MarkerTapped="{updateInfo}" ShowMyLocationButton="true" AllowZoom="false" ShowMyLocation="true" Latitude="59.910617" Longitude="10.728045" Zoom="12" >
        <Each Items="{contactInfo}">
          <MapMarker Latitude="{Latitude}" Longitude="{Longitude}" Label="{Label}"/>
        </Each>
      </MapView>
    </NativeViewHost>

    <Each Items="{contact}">
      <Text Value="{Label}"/>
    </Each>

```

But theres no text and actually on my sony x3 the app crashes after a minute after tapping a couple of markers

---

<div class="post-metadata">

**Author:** ![Remi\_Pedersen](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/remi_pedersen/32/432_2.png) [@Remi\_Pedersen](https://forums.fusetools.com/u/Remi_Pedersen)\
**Post date:** [March 15, 2017, 11:44am UTC](https://forums.fusetools.com/t/mapview-markertapped-updating-observables/527/2 "2017-03-15T11:44:37Z")

</div>

`contact.add(arg);` - What you’re doing here is to add the entire data context for MapView to your observable. I suspect this might be why something crashes after a while.

Also, note that the label passed to [MarkerTapped](https://www.fusetools.com/docs/fuse/controls/mapview/markertapped) is is all lowercase. E.g. it’s `arg.label` without capital “L”.

What you want to do is probably: `contact.add({"Label": arg.label});`

And a small tip: when having trouble with handlers and their arguments it can be useful to do a `console.log(JSON.stringify(arg))` just to work out what’s in there. 🙂