[GIS] Openlayers redraw layers: consecutive redraw calls not working

geoserveropenlayers-2wms

SETUP

OpenLayers / GeoServer + PostGIS

REQUIREMENT

I have a map with multiple WMS layers and of these I need to refresh a few after inserting a polygon in one of the layers.

PROBLEM

Given below are three options of the AJAX success callback function on successful insert of polygon geometry in the PostGIS backend and the corresponding errors/observations.

Option 1: 

if(data == "SUCCESS")
{
   map.getLayersByName('dummy_nodes')[0].redraw(true);
   map.getLayersByName('bldg_logical')[0].redraw(true);  
}

// Throws error: Uncaught TypeError: Cannot call method 'redraw' of undefined

Option 2: 

var tempLayer;
if(data == "SUCCESS")
{
   map.getLayersByName('dummy_nodes')[0].redraw(true);
   console.log("Prev cmd is successful");
   tempLayer = map.getLayersByName('bldg_logical')[0]
   tempLayer.redraw(true);  
}

// Outputs: 'Prev cmd is successful'
// tempLayer gives proper layer object: OpenLayers.Layer.WMS.OpenLayers.Class.initialize {metadata: Object, options: Object, singleTile: true, ratio: 1, isBaseLayer: false…}
// But still throws error: Uncaught TypeError: Cannot call method 'redraw' of undefined

Option 3: 

if(data == "SUCCESS")
{
   map.getLayersByName('dummy_nodes')[0].redraw(true);
}

// Works fine (but I need both layers to be refreshed)

QUESTIONS

Could anyone let me know why the error occurs?
Is my usage wrong?
Does it have to do anything with the order in which the layers have been added to the map?

Best Answer

It looks to me like your layers named 'bldg_logical' don't exist. 'Undefined' means you have an uninitialized property. This implies that the getLayersByName method isn't finding any layers named 'bldg_logical'.

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