[Chameleon] js api: run query

[Bart van den Eijnden]

Hi list,

I have managed to get this running, so I thought I'd share my solution. My approach needed changes to UpdateMap.php only. Paul/Julien, are there plans for adding query highlight functionality to UpdateMap.php? Would you guys be interested in getting this in the Chameleon distro?

My approach does have an assumption: all layers which need to be query-highlighted need to have a FILTERITEM defined (using an empty FILTER "" in order to get everything rendered). I like this approach better than a client having to send the name of a column to the server.

When a node from the treeview is clicked, I run the following javascript (this is now part of my custom js file included in my app, but could become part of cwcjsapi.js in the future) :

function CWCRunQuery(layername, filter)
{
     CWCDHTML_ShowLayer("ActivityLayer");

     aHiddenVars = new Array(3);
     aHiddenVars[0] = new Array(2);
     aHiddenVars[0][0] =  "LAYER_RUN_QUERY";
     aHiddenVars[0][1] = "1";

     aHiddenVars[1] = new Array(2);
     aHiddenVars[1][0] =  "LAYER_NAME";
     aHiddenVars[1][1] = layername;

     aHiddenVars[2] = new Array(2);
     aHiddenVars[2][0] =  "LAYER_FILTER";
     aHiddenVars[2][1] = filter;

      // we need to update the map as well
     goCWCJSAPI.CallServer("goCWCJSAPI.MapExtentsUpdated()", aHiddenVars);
     return true;
}

The changes I did to UpdateMap.php are (adding a selection layer dynamically which is a copy of the layer which needs to be query-highlighted, and setting the color to a selection color):

if (isset( $HTTP_FORM_VARS["LAYER_RUN_QUERY"]) &&
    $HTTP_FORM_VARS["LAYER_RUN_QUERY"] != "")
{
    $oMap = $oMapSession->oMap;

    // if selection layer exists, delete it first
    for ( $i=0; $i<$oMap->numlayers;  $i++ )
    {
      $oTempLayer = $oMap->getlayer($i);
      if ( $oTempLayer->name == 'StraGISWebSelection' )
      {
        $oTempLayer->set( 'status', MS_DELETE );
        break;
      }
    }

    $szLayerName = "";
    if (isset($HTTP_FORM_VARS["LAYER_NAME"]))
      $szLayerName = $HTTP_FORM_VARS["LAYER_NAME"];

    $szFilter = "";
    if (isset($HTTP_FORM_VARS["LAYER_FILTER"]))
      $szFilter = $HTTP_FORM_VARS["LAYER_FILTER"];

    for ($i=0; $i<$oMap->numlayers; $i++)
    {
      $oLayer = $oMapSession->oMap->GetLayer($i);
      if ($oLayer->name == $szLayerName)
      {
        // copy layer
        $oSelectionLayer = ms_newLayerObj( $oMap, $oLayer );
        $oSelectionLayer->set( 'name', 'StraGISWebSelection' );
        $oSelectionLayer->set( 'template', '' );
        $oSelectionLayer->setFilter($szFilter);
        // set color to selection color
        for( $j=0; $j < $oSelectionLayer->numclasses; $j++)
        {
          $oClass = $oSelectionLayer->getClass($j);
          for ($k=0;$k<$oClass->numstyles;$k++)
		  {
            $oStyle = $oClass->getStyle($k);
            $oStyle->color->setRGB( 255,255,0 );
          }
        }
        $oSelectionLayer->set( 'status', MS_ON );
      }
    }
    $_SESSION["gszCurrentState"] = $oMapSession->saveState();
}

Best regards,
Bart

Bart van den Eijnden
Syncera-ITSolutions
Postbus 270
2600 AG  DELFT

tel.nr.: 015-7512436
email: BEN at Syncera-ITSolutions.nl

>>> "Bart van den Eijnden" <BEN at syncera-itsolutions.nl> 05/17/05 04:41pm >>>
Hi list,

I am faced with the following problem:

I have a treeview next to my MapDHTML. When a node in the treeview is clicked, I need to highlight the item in the map. I do know how to do this with PHP/Mapscript (savequery etc.), but I don't know how to do this from the js api mode.

I can't see any place in the JS API to pass a query and request for an updated map.

Would this require changes to the UpdateMap.php file as well as the cwcjsapi.js file? Or am I missing something? What would be the best approach for this?

Best regards,
Bart

Bart van den Eijnden
Syncera-ITSolutions
Postbus 270
2600 AG  DELFT

tel.nr.: 015-7512436
email: BEN at Syncera-ITSolutions.nl 


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