arcpy.mapping.AddLayer invisible layer [closed]

Question

I'm having a bit of a problem with a script on a particular machine.

==========================================================

import arcpy,sys


class AddLayer(object):

    '''
    classdocs
    '''

   def __init__(self,sNewHabFile,workspace):

        scriptPath = sys.path[0]
        f = file(scriptPath + chr(92) +'AddLayerFile_ArcGIS_log.txt', 'w') # open for 'w'riting

        f.write("Add layer file initialised") # write text to file
        f.write("\n")

        layerFile = sNewHabFile + ".lyr"
        f.write(str(layerFile)) # write text to file
        f.write("\n")

        mxd = arcpy.mapping.MapDocument("CURRENT")

        f.write(str(mxd.filePath)) # write text to file
        f.write("\n")

        addLayer = arcpy.mapping.Layer(layerFile)

        f.write(str(addLayer.name)) # write text to file
        f.write("\n")

        df = arcpy.mapping.ListDataFrames(mxd)[0]

        f.write(str(df.name)) # write text to file
        f.write("\n")

        arcpy.mapping.AddLayer(df, addLayer, "TOP")

        f.write("Layer added?") # write text to file
        f.write("\n")

        layer = arcpy.mapping.ListLayers(mxd)[0]

        f.write("First layer is called:" + str(layer.name)) # write text to file
        f.write("\n")

        arcpy.RefreshTOC()
        '''
        end
        '''

============================================================

It's working fine on my machine, but testing the whole tool on another machine, AddLayer here and in another module I have written does not throw up an error, it just doesn't add the final outputs to the map.

As you can see above I have writen to a text file and layer = arcpy.mapping.ListLayers(mxd)[0]

and

f.write("First layer is called:" + str(layer.name))

are writing the correct layer to the text document, but I can't see anything in the TOC.

I can manually add the created data.

On my original machine, which is working I am running:

ArcView single use with Spatial Analyst, 4th or 5th service pack I think.

The machine that is not working is running ArcEditor concurrent with access to Spatial Analyst, this is likely to be a much earlier service pack (either none or 1 or 2).

Does anyone have any ideas?

Answer 1

Sounds like you would need to use

arcpy.RefreshTOC()

After you add the layer but before you call ListLayers method.

    ...
    arcpy.mapping.AddLayer(df, addLayer, "TOP")

    #add the refresh method to update the TOC
    arcpy.RefreshTOC()

    f.write("Layer added?") # write text to file
    f.write("\n")

    layer = arcpy.mapping.ListLayers(mxd)[0]
    ...

I see you call the refresh at the end. But you basically need it anytime you make a change and want to see the effect.

---

RefreshTOC has two other useful siblings...

If you need to see the change on the map view you will need

arcpy.RefreshActiveView()

In addition, if you happen to create/rename/remove anything spatial and Esri isn't recognizing that change you may need to refresh the catalog (in this case passing it the object you want refreshed)

arcpy.RefreshCatalog(someTargetObject)

Answer 2

I ran into the same problem and found that the solution was to do mxdDoc.saveACopy("C:\\mxdcopy.mxd")