replaceMarkers not working in 1.0.2

[Kosmas]

Having upgraded from 0.11 to 1.0.2, the replaceMarkers function does not work.

I'm using the last position to update the marker.

When there is no update in the last position there is no error in the function.

If there is an update then the following error is displayed:

marker.serviceObject is undefined marker.seviceObject.setMap(null);

Have tried with the addMarkers and seems to be working fine:

The code used, which is defined below the actual map creation in the view is the following:

<% content_for :scripts do -%>
    <script type="text/javascript" charset="utf-8">
      $(function() { setInterval(function(){$.getJSON("/gps_positions.json", function(data){
        Gmaps.map.replaceMarkers(data);
        })},30000)});
    </script>

[apneadiving]

Basically, markers is an array containing marker object. Marker contains the value from the json + a serviceObject which is created by the map provider.

In your case, it seems one marker doesn't have any serviceObject which means it isn't displayed on the map.

Could you please check why the marker has no serviceObject, ie what's the sequence leading to this situation?

I'll re-add the if condition on serviceObject existence, I simply hope there not a deeper bug here.

[apneadiving]

ok found out one bug, but didn't have the same error message. I'm gonna release 1.1.1, please tell me if it's ok.

[walter]

Hi,

I'm encountering something similar using 1.1.2 version of the gem on Safari (haven't tried another browser yet). Here's the background code:

// in dragend listener triggered function, update marker with out new latValue and lngValue var newMarkers = [{\"lng\":latValue,\"description\":\"blah\", \"lat\":lngValue, \"draggabel\": true}]

gmaps4RailsMap.replaceMarkers(newMarkers);

The dragged marker disappears as expected at dragend, but no new marker is shows up visibly. However if I go to the console I can see the map has the marker and it has a serviceObject:

Gmaps.still_image_extended_content_values_location_map_div.markers[0] Object description: "blah" draggabel: true lat: 175.22250520833302 lng: -37.789144699240445 serviceObject: W _e3: Object __gm_id: 80 b: null draggable: true gmaccessors: Object map: null position: P q: false title: null visible: false ...

However, the map attribute in the serviceObject is null and the visible attribute is false. I've tried manipulating these attributes with showMarkers() and serviceObject.setMap(Gmaps.still_image_extended_content_values_location_map_div.map), but the marker still doesn't appear.

Been trying to get this to work for most of today, would appreciate it if this gets fixed!

[apneadiving]

@walter: this time I'm pretty sure of my code + I've tests + I've sample app with a sample to check inside the browser (I did with safari too).

Well, I could be wrong, but I'm still wondering if you don't have a closure problem here.

Could you copy paste your whole code in a gist?

[walter]

Hi,

Here's everything involved:

https://gist.github.com/1202775

The most relevant function definition is at line 64.

Thanks for looking into this.

Cheers, Walter

On Sep 8, 2011, at 6:14 PM, Benjamin Roth wrote:

@walter: this time I'm pretty sure of my code + I've tests + I've sample app with a sample to check inside the browser (I did with safari too).

Well, I could be wrong, but I'm still wondering if you don't have a closure problem here.

Could you copy paste your whole code in a gist?

Reply to this email directly or view it on GitHub: https://github.com/apneadiving/Google-Maps-for-Rails/issues/83#issuecomment-2036989

[apneadiving]

Wow, ok I'll look at it in the next 24 hours :)

Just to be sure: have you tried to call replaceMarkers directly from js console in browser?

[walter]

Hi again,

Ok, yeah, gave that a go. Here's what I did:

• commented out the 'var newMarkers...' and replaceMarkers calls in updateMapData function
• loaded the page
• dragged the marker to a new location (text input field updated as expected and marker, because "replaceMarkers" wasn't called, persisted)
• copied that new lat/lng value and put this together in the console:

var newMarkers = [{"lng": -37.789144699240445, "description": 'blart', "lat": 175.31039583333302, "draggabel": true}];

Gmaps.still_image_extended_content_values_location_map_div.replaceMarkers(newMarkers);

The marker disappeared, but no new marker took its place. I did a little further inspection from the console:

Gmaps.still_image_extended_content_values_location_mapdiv.markers[0] Object • description: "blart" • draggabel: true • lat: 175.31039583333302 • lng: -37.789144699240445 • serviceObject: W • **e3: Object • __gm_id: 407 • b: null • draggable: true • gmaccessors: Object • map: null • position: P • q: false • title: null • visible: false • __proto: W • proto**: Object

Same map null and visible false as before.

Best, Walter

---

Walter McGinnis Kete Project Lead (http://kete.net.nz) Katipo Communications, Ltd. (http://katipo.co.nz) http://twitter.com/wtem +64211241794

On Sep 8, 2011, at 6:40 PM, Benjamin Roth wrote:

Wow, ok I'll look at it in the next 24 hours :)

Just to be sure: have you tried to call replaceMarkers directly from js console in browser?

Reply to this email directly or view it on GitHub: https://github.com/apneadiving/Google-Maps-for-Rails/issues/83#issuecomment-2037134

[apneadiving]

Just edited your gist (untested though). I guess you indeed have a closure problem.

[Kosmas]

Just tried with the new version but have the same error and below is the full description. Not sure where or what I should be looking at but if you have an idea would be great

clearMarker(marker=Object { lng="8.5155", lat="47.3768"})gmaps4...maps.js (line 191)
marker = Object { lng="8.5155", lat="47.3768"}
clearMarkers()gmaps4...maps.js (line 173)
replaceMarkers(new_markers=[Object { lng="8.5155", lat="47.3768"}, Object { lng="8.5155", lat="46.3768"}, Object { lng="8.5155", lat="46.2768"}, 10 more...])gmaps4...base.js (line 373)
new_markers = [Object { lng="8.5155", lat="47.3768"}, Object { lng="8.5155", lat="46.3768"}, Object { lng="8.5155", lat="46.2768"}, 10 more...]
(?)(data=[Object { lng="8.5155", lat="47.3768"}, Object { lng="8.5155", lat="46.3768"}, Object { lng="8.5155", lat="46.2768"}, 10 more...])gps_positions (line 189)
data = [Object { lng="8.5155", lat="47.3768"}, Object { lng="8.5155", lat="46.3768"}, Object { lng="8.5155", lat="46.2768"}, 10 more...]
resolveWith(context=Object { url="/gps_positions.json", isLocal=false, more...}, args=[[Object { lng="8.5155", lat="47.3768"}, Object { lng="8.5155", lat="46.3768"}, Object { lng="8.5155", lat="46.2768"}, 10 more...], "success", Object { readyState=4, responseText="[{"lng": "8.5155", "lat...55", "lat": "46.3768"}]", more...}])jquery...4799549 (line 1008)
context = Object { url="/gps_positions.json", isLocal=false, more...}
args = [[Object { lng="8.5155", lat="47.3768"}, Object { lng="8.5155", lat="46.3768"}, Object { lng="8.5155", lat="46.2768"}, 10 more...], "success", Object { readyState=4, responseText="[{"lng": "8.5155", "lat...55", "lat": "46.3768"}]", more...}]
done(status=200, statusText="success", responses=Object { text="[{"lng": "8.5155", "lat...55", "lat": "46.3768"}]"}, headers="Content-Type: applicati...MT\nContent-Length: 481\n")jquery...4799549 (line 7168)
status = 200
statusText = "success"
responses = Object { text="[{"lng": "8.5155", "lat...55", "lat": "46.3768"}]"}
headers = "Content-Type: applicati...MT\nContent-Length: 481\n"
callback(_=readystatechange , isAbort=undefined)jquery...4799549 (line 7947)
_ = readystatechange
isAbort = undefined
```ruby

[apneadiving]

@Kosmas: could you please show me your code?

[Kosmas]

Sure thing:

Controller:

  respond_to :json, :html

  def index
    @gps_positions = GpsPosition.find(:all)
    @gps_positions_json = @gps_positions.to_gmaps4rails

    @last_position = GpsPosition.last

    respond_with @gps_positions_json
  end

and the view :

<% if @gps_positions.empty? %>
  <p>no entries found</p><br/>
<% else %>

  <!--<div id="map">-->
    <%= gmaps("map_options" => {"zoom" => 9, 
                                "center_longitude" => @last_position.lng, 
                                "center_latitude" => @last_position.lat,
                                "auto_adjust" => false,
                                "auto_zoom" => false},
              "markers" => {"data" => @gps_positions_json}) %>
  <!--</div> -->
    <% content_for :scripts do -%>
      <script type="text/javascript" charset="utf-8">
        $(function() { setInterval(function(){$.getJSON("/gps_positions.json", function(data){
          Gmaps.map.replaceMarkers(data);
        })},30000)});
      </script>
    <% end -%>

  <div class="table">
    <table>
      <th>Latitude</th>
      <th>Longitude</th>
      <th>Created at</th>
      <% for gps_position in @gps_positions %>
        <tr class="<%= cycle('list_line_odd', 'list_line_even') %>">
          <td><%=h gps_position.lat %></td>
          <td><%=h gps_position.lng %></td>
          <td><%=h render_datetime(gps_position.created_at) %></td>
        </tr>
      <% end %>
    </table>
  </div>
<% end %>

[apneadiving]

Ok. As you described earlier, the marker itself isn't even created.

So serviceObject is null and clearMarker fails...

I could check serviceObject existence before trying to clear. That would solve the problem. Yet I can't understand why some of your markers aren't processed. I guess it's linked to the setInterval function but am not sure.

To conclude, the problem is not from replaceMarkers but from clearMarker working on an invalid set of data.

[apneadiving]

To be more precise, you shouldn't set an absolute timeout, but a relative one: the json calls could be long and this mess things up.:

• call (1) too long
• call(2) too long
• process of data from (1)

...

So you should wait for the end of the first call + process, then wait for some time, then retrigger the call:

• call
• wait the end of process
• add the delay you want
• call

[apneadiving]

(Bascially, I suggest you use setTimeout). http://www.w3schools.com/js/js_timing.asp