turning on/off layers in Mapguide Enterprise

[scluna]

How do I turn on or off a layer. Could anyone provide a code snippet?

Thanks

[jumpinjackie]

get the MgLayer object in question from your MgMap object.

call SetVisible(false) on that layer object. Save your map object and do a refresh on the client side.

here's a php example:

$map = new MgMap();
$map->Open($resourceService, $mapName);

$layerName = "Parcels";
$visible = true; //or false

$mapLayers = $map->GetLayers();
$layer = null;
for($i = 0; $i < $mapLayers->GetCount(); $i++)
{
$currentLayer = $mapLayers->GetItem($i);
if($currentLayer->GetName() == $layerName)
{
$layer = $currentLayer;
}
}

if($layer != null)
{
$layer->SetVisible($visible);
$layer->ForceRefresh();
$map->Save($resourceService);
}

[scluna]

thanks for the idea.
actually i have run may asp.net code and getting an MgUnclassified Exception. when I turn the layers on and off.
The error is in line 22 when i pass the sessionid.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: OSGeo.MapGuide.MgUnclassifiedException: An unclassified exception occurred.

Source Error:


Line 20: InitializeWebTier();
Line 21:
Line 22: MgUserInformation userInfo = new MgUserInformation(SessionId);
Line 23: MgSiteConnection siteConnection = new MgSiteConnection();
Line 24: siteConnection.Open(userInfo);

___________________________________________
MgLayerCollection LayerCol = map.GetLayers();
MgLayer layer = LayerCol.GetItem("Soils");
if (layer.IsVisible())
{
layer.SetVisible(false);
}
else
{
layer.SetVisible(true);
}

layer.ForceRefresh();
map.Save(resourceService);

[jumpinjackie]

Try the following:

- Check the value of sessionId, it's gotta look like a long string of hexadecimal numbers.

- Wrap that code in a try-catch block, catch MgException and call its GetDetails(). Hopefully, that can reveal more information.

[SAustin]

I've gotten that error when trying to change the visibility of base map layers with AJAX viewer. Here is a quote from the Web API Reference doc that helped me:

the visibility of base map layers (those of type MgLayerType::BaseMap) cannot be changed. Attempting to do so will throw an MgInvalidOperationException

http://mapguide.osgeo.org/files/mapguide/docs/webapi/d6/de2/class_mg_layer_1970fbe700599c7fd6f8603708158486.html#1970fbe700599c7fd6f8603708158486

[scluna]

Thanks jackie/SAustin,

I already made a workaround on this and it's working now.

[ales6]

Hi SCLuna

Currently searching solution (workaround) form my .net sample
..did not found solution how to fix the problem.

I still get message:
Type 'OSGeo.MapGuide.MgUnclassifiedException' in Assembly 'MapGuideDotNetApi, Version=1.1.0.301, Culture=neutral, PublicKeyToken=null' is not marked as serializable.

Can you help me, please.

by ales6

[SAustin]

This is actually possible with base layers Here is some info that I used in my solution.
http://www.nabble.com/Fwd:-Swithing-base-MgLayerGroup-on-off-...-fails--td14454152.html

[mitchellhastings1484]

Thanks for the code Jakie.

I added a snipet to the search.php to turn on a layer that was being searched if it was off by default.

below is the code I added an else statement at the end.  Seems to work ok.

try
{
$featureSrvc = $siteConnection->CreateService(MgServiceType::FeatureService);

//Create a temporary map runtime object, locate the layer
$map = new MgMap();
$map->Open($resourceService, $mapName);
$layers = $map->GetLayers();
$layer = null;
//fwrite($logHandle,"found layers:".$layers->GetCount()."\n");
for($i = 0; $i < $layers->GetCount(); $i++)
{
$layer = $layers->GetItem($i);
//fwrite($logHandle,"found layer:".$layer->GetName()."\n");
if($layer->GetName() == $layerName)

break;
}

if($layer == null)
{
trigger_error(FormatMessage("SEARCHLAYERNOTFOUND", $locale, array($layerName)));
}
else
{
$layer->SetVisible($visible);
$layer->ForceRefresh();
$map->Save($resourceService);
}