[GIS] Using Python Add-In to delete/remove ArcMap layers that are turned off

arcgis-desktoparcpylayerspythonpython-addin

I have made a python addin button which removes layers that are turned off in an MXD. The strange thing is that I get different results depending on whether I run the python commands in the python window vs my actual addin button.

In my addin class, the code looks like this:

def onClick(self):
        mxd = arcpy.mapping.MapDocument("CURRENT")
        layerList = arcpy.mapping.ListLayers(mxd)
        for layer in layerList:
            if layer.visible == False:
                arcpy.Delete_management(layer)
        arcpy.RefreshTOC()

So, this works fine in the python window but doesn't do anything in the button. I assume because it's trying to delete a layer object instead of the name. I have made a workaround which changes the following line:

arcpy.Delete_management(layer.name)

Now this actually works. But there is a caveat, if I have multiple layers with the same name but different visibility settings, it may delete the one that is visible. My second workaround is to change the layer name before I delete it.

My final code looks like this:

def onClick(self):
        mxd = arcpy.mapping.MapDocument("CURRENT")
        layerList = arcpy.mapping.ListLayers(mxd)
        for layer in layerList:
            if layer.visible == False:
                layer.name += '_'
                arcpy.Delete_management(layer.name)
        arcpy.RefreshTOC()

By changing the name of the layer, I'm ensuring that I only delete invisible layers. But I'm wondering if this is the best way to go about doing this.

My question is, is there a better way to remove layers that are not visible from an MXD? Especially when they have the same name?

Best Answer

It would be better to remove the layer using arcpy.mapping.RemoveLayer. The parameters are the data frame to remove the layer from (possibly a group layer if you are trying to remove from a group) and the layer itself, this alleviates any chance of confusion:

def onClick(self):
        mxd = arcpy.mapping.MapDocument("CURRENT")
        df = arcpy.mapping.ListDataFrames(mxd)[0] # assume only one data frame
        layerList = arcpy.mapping.ListLayers(mxd)
        for layer in layerList:
            if layer.visible == False:
                arcpy.mapping.RemoveLayer(df,layer)
        arcpy.RefreshTOC()

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[GIS] Add AutoCAD .dwg annotation file to Arcmap using python (Same as +ADD Data button)

The answer to your question lies in understanding that even though it is referred to as Annotation, it is still coming from a CAD drawing.

This ESRI Help document lists the Supported AutoCAD entities.

This Help document talks about ArcGIS Annotation: What is annotation?

There are a lot of differences. The most important being that all CAD data is Read-Only in ArcGIS. You can load in data and symbolize in different ways, but if you want to edit anything it has to be converted to a different spatial format first.

ArcGIS Annotation on the other hand is editable like any other feature class in a geodatabase, along with the ability to add different attributes.

In short, if you want to add CAD Annotation as an Annotation Feature Class, you first have to convert it to Geodatabase Annotation. Here is a help document that describes this process: Import CAD Annotation (Conversion)

-------- Edit

With a clearer head, I reread your question, and realized there are two different ways of understanding it. 1. Is like above where I thought you wanted to bring it in as an actual ArcGIS Annotation layer.
2. Is that you simply want to load the layer in to show the CAD annotation as text, and not have it represented as a point featureclass as in your first diagram.

The way to do this requires using a different type of Layer function, not the one in arcpy.mapping, but instead the geoprocessing type, with this command: Make Feature Layer
This command creates a Feature Layer in memory, but also adds it to your current Map. The difference between this and the arcpy.mapping Layer class is that you are able to specify not only the Annotation Layer of the CAD drawing, but also specify that this dataset is of type CAD. This changes the way that ArcGIS reads the file.

Once you have added the layer to the map, you may simply add it to your Group Layer. Here is some code that takes a referenced CAD drawing, pulls out the Annotation portion, creates a Feature Layer and adds it to the Group Layer

import arcpy

#Reference current MXD
mxd = arcpy.mapping.MapDocument("CURRENT")

#Directory containing CAD File
cadpath = r"C:\City_GIS\Projects\Python"

#Set environment workspace
arcpy.env.workspace = cadpath

#Return specific drawing name from list of datasets
dwgname = arcpy.ListDatasets("C-6*","CAD")[0]

#Returns desired dataframe from current MXD
dataframe = arcpy.mapping.ListDataFrames(mxd,"Layers")[0]

#Return desired group layer to add Annotation to
grouplayer = arcpy.mapping.ListLayers(mxd,"CADLayers",dataframe)[0]

#Name of new layer to be created
cadname = dwgname + "_anno"

#Create Temporary Feature Layer, which also adds to Map document
arcpy.MakeFeatureLayer_management(dwgname + "/Annotation",cadname)

#Refresh Table of Contents
arcpy.RefreshTOC

#Search MXD list to return Layer
layertogroup = arcpy.mapping.ListLayers(mxd,cadname)[0]

#Add this returned layer to your group layer
arcpy.mapping.AddLayerToGroup(dataframe,grouplayer,layertogroup)

This will create two copies of the layer on your Map. The one will be outside and one inside the Group layer. You can then set up code to remove the one that is outside the group layer.

It is a bit convoluted, but I hope it approaches what you were trying to accomplish. Here is a screenshot of the result.

Screenshot of CAD Annotation Layer

[GIS] Iterating through all geometries using ArcPy search cursor

You are collecting the extents for each polygon correctly, but need to zoom to them within the loop, or a later loop depending on what you want to do.

For example to zoom in the same loop as the search cursor e.g.

with arcpy.da.SearchCursor(SelLayer,"SHAPE@") as SCur:
    for feat in SCur:
        # I'm going to assume polygon/polyline
        Envelopes.append(feat[0].extent) # grab the envelope 
        df.extent = feat[0].extent # first extent # <- Move this into the loop
        arcpy.RefreshActiveView()

        time.sleep(5) # Wait 5 Seconds. 
        # ^ Replace this with what you want to do at each poly.

Best Answer

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[GIS] Add AutoCAD .dwg annotation file to Arcmap using python (Same as +ADD Data button)

[GIS] Iterating through all geometries using ArcPy search cursor

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