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    Hello,<br>
    <br>
    I think I have exactly the same problem. I have vector layer with
    many points-markers. I need to limit the number of fetched points
    from server becouse of performance.<br>
    The vectorlayer use bbox strategy and protocol HTTP:<br>
    <br>
    weather_points_layer = new OpenLayers.Layer.Vector("Wetterpunkte", {<br>
                    <br>
                    strategies: [new OpenLayers.Strategy.BBOX({ratio:
    1.1})], <br>
    <br>
                    protocol: new OpenLayers.Protocol.HTTP({<br>
                        url: "text_layer_generator/weather_points.php"<br>
                    ..<br>
                    })<br>
                });<br>
    <br>
    The script: weather_points.php limits the number of points using
    bbox parameter and LIMIT statement in sql query.<br>
    There is the working example: <a class="moz-txt-link-freetext" href="http://mapakrakow.pl/pogoda/test.php">http://mapakrakow.pl/pogoda/test.php</a><br>
    When I zoomin the points are not fetched from server but from
    browser cache. Problem is that when you zoomin to - for example 
    Berlin - you don't see any points. There is not any request in
    firebug fetching the data.<br>
    <br>
    Running this command:<br>
    weather_points_layer.refresh({force:true}); <br>
    in firebug console Openlayers requests and refreshes the data from
    server correctly and shows points over Berlin.<br>
    I tryed to change cache-control headers in weather_points.php:<br>
    <br>
    #header("Cache-Control: max-age=2"); // HTTP/1.1<br>
    #header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the
    past<br>
    #header("Pragma: Cache"); // required <br>
    //header("connection: close");<br>
    //Keep-Alive    timeout=2, max=100<br>
    <br>
    and add the refresh strategy:<br>
    strategies: [new OpenLayers.Strategy.BBOX({ratio: 1.1}), new
    OpenLayers.Strategy.Refresh()], <br>
    <br>
    but both didn't helped.<br>
    I fond this article:
<a class="moz-txt-link-freetext" href="http://stackoverflow.com/questions/2995238/how-to-refresh-reload-a-kml-layer-in-openlayers-dynamic-kml-layer">http://stackoverflow.com/questions/2995238/how-to-refresh-reload-a-kml-layer-in-openlayers-dynamic-kml-layer</a><br>
    But I don't need to refresh vectorlayer in constant time interval
    but every time when user manipulates the map.<br>
    <br>
    Has someone experience how to solve this problem?<br>
    Thanks for your help.<br>
    <br>
    Bartlomiej Burkot<br>
    <br>
    <br>
    W dniu 2012-03-07 16:56, Jan Hartmann pisze:
    <blockquote cite="mid:4F578549.2020309@uva.nl" type="cite">
      <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
      <font face="Times New Roman, Times, serif">No, it tried that.
        According to the documentation, the redraw function does not
        take a parameter.<br>
        <br>
        Jan<br>
      </font><br>
      On 03/07/2012 04:45 PM, <a moz-do-not-send="true"
        class="moz-txt-link-abbreviated"
        href="mailto:Steve.Toutant@inspq.qc.ca">Steve.Toutant@inspq.qc.ca</a>
      wrote:
      <blockquote
cite="mid:OF955F754E.8928EC6B-ON852579BA.005669C4-852579BA.00568C82@isn.rtss.qc.ca"
        type="cite">
        <meta http-equiv="Content-Type" content="text/html;
          charset=UTF-8">
        <br>
        <font size="2" face="sans-serif">Is this working?</font> <br>
        <font size="2" face="sans-serif">vectorLayer.redraw(true);<br>
        </font> <br>
        <br>
        <br>
        <br>
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              <td width="40%"><font size="1" face="sans-serif"><b>Jan
                    Hartmann <a moz-do-not-send="true"
                      class="moz-txt-link-rfc2396E"
                      href="mailto:j.l.h.hartmann@uva.nl">&lt;j.l.h.hartmann@uva.nl&gt;</a>@lists.osgeo.org</b>
                </font> <br>
                <font size="1" face="sans-serif">Envoyé par : <a
                    moz-do-not-send="true"
                    class="moz-txt-link-abbreviated"
                    href="mailto:openlayers-users-bounces@lists.osgeo.org">openlayers-users-bounces@lists.osgeo.org</a></font>
                <p><font size="1" face="sans-serif">2012-03-07 10:27</font>
                </p>
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                        <div align="right"><font size="1"
                            face="sans-serif">A</font></div>
                      </td>
                      <td><font size="1" face="sans-serif"><a
                            moz-do-not-send="true"
                            class="moz-txt-link-abbreviated"
                            href="mailto:openlayers-users@lists.osgeo.org">openlayers-users@lists.osgeo.org</a></font>
                      </td>
                    </tr>
                    <tr valign="top">
                      <td>
                        <div align="right"><font size="1"
                            face="sans-serif">cc</font></div>
                      </td>
                      <td> <br>
                      </td>
                    </tr>
                    <tr valign="top">
                      <td>
                        <div align="right"><font size="1"
                            face="sans-serif">Objet</font></div>
                      </td>
                      <td><font size="1" face="sans-serif">[Polluriel
                          potentiel]  [OpenLayers-Users] force update
                          markers layer</font></td>
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                      <td> <br>
                      </td>
                      <td><br>
                      </td>
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        <br>
        <br>
        <br>
        <br>
        <font size="3" face="Times New Roman">Hi,<br>
          <br>
          How do I force a redraw on a markers layer? I have a regular
          WMS map with markers that have their lonlat-values updated
          from a database. I can force a redraw of the WMS layer with
          mergenewparams(), but that is not possible with the markers
          layer. That means that the when the lonlat values are updated
          and I move the map, the markers remain in their original
          positions. Only when I zoom in or out, the marker positions
          are updated. Can I do something about that?<br>
          <br>
          Jan</font><tt><font size="2">_______________________________________________<br>
            Users mailing list<br>
            <a moz-do-not-send="true" class="moz-txt-link-abbreviated"
              href="mailto:Users@lists.osgeo.org">Users@lists.osgeo.org</a><br>
            <a moz-do-not-send="true" class="moz-txt-link-freetext"
              href="http://lists.osgeo.org/mailman/listinfo/openlayers-users">http://lists.osgeo.org/mailman/listinfo/openlayers-users</a><br>
          </font></tt> <br>
        <br>
        <br>
      </blockquote>
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      <pre wrap="">_______________________________________________
Users mailing list
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</pre>
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