topic Re: How to add Legend to layer in ModelBuilder in User Conference Questions

How to add Legend to layer in ModelBuilder

NickPopow — Tue, 26 Aug 2014 06:45:56 GMT

Dear All!

I'm trying to add a legend to layer in modelbuilder. Help pages say that I need to use "Apply Symbology From Layer" tool. I have saved my Symbology Layer but it doesn't consist my legend (as I understood a legend can be saved only in Map file). Could you please explain me how to do this correctly?

Re: How to add Legend to layer in ModelBuilder

NaimeCelik — Mon, 01 Sep 2014 07:35:48 GMT

If I understood correctly, you want to add legend with model builder.Apply Symbology From Layer extracts Symbology from a layer ( which is a layer you prepared before) to another layer which does not have symbology.

As far as I know , there is no tool to include legend in model builder but you could create a script "to add legend" in python and make a tool with that script. Then you can add it to your model. Here same code you can use to create layer from shp and add sybology.

import arcpy

symbologyLayer=r"C:\.....\sembology.lyr" # if you want to assign same layer format all the time this can be a path to your symbology

LabelExpression="[Fieldyouwantolabelwith]" #if you want label you can make it parameter if not you do not have to use this label parts

K_shp= arcpy.GetParameterAsText(0) ### your shp file you want to assign symbology

## those above will be your parameters

mxd = arcpy.mapping.MapDocument(r"C:\......\my.mxd")

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

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

arcpy.MakeFeatureLayer_management(K_shp,"Layername")

lyr1= arcpy.mapping.Layer("Layername")

arcpy.ApplySymbologyFromLayer_management (lyr1, symbologyLayer)

lyr1.labelClasses[0].expression = LabelExpression

lyr1.showLabels = True

legend = arcpy.mapping.ListLayoutElements(mxd, "LEGEND_ELEMENT", "Legend")[0]

legend.autoAdd = True

arcpy.RefreshActiveView()

arcpy.mapping.AddLayer(df, lyr1, "BOTTOM")

Re: How to add Legend to layer in ModelBuilder

NaimeCelik — Mon, 01 Sep 2014 09:09:28 GMT

Ok I created tool and here how you do it.

This is the tool view below

Here the script for it

import arcpy,os

symbologyLayer=arcpy.GetParameterAsText(2)

LabelExpression=arcpy.GetParameterAsText(1)

try:

for idx, item in enumerate(LabelExpression.split()):

if 'VISIBLE'==item:

num=idx

arcpy.AddWarning(LabelExpression.split()[idx-1])

LabelExpression="["+LabelExpression.split()[num-1]+"]"

except:

arcpy.AddError("Choose only one field name for label expession")

K_shp=arcpy.GetParameterAsText(0)

add_legend= arcpy.GetParameterAsText(3)

LayerName=os.path.split(K_shp)[1][:-4]+"_lyr"

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

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

arcpy.MakeFeatureLayer_management(K_shp,LayerName)

lyr1= arcpy.mapping.Layer(LayerName)

arcpy.ApplySymbologyFromLayer_management (lyr1, symbologyLayer)

lyr1.labelClasses[0].expression = LabelExpression

lyr1.showLabels = True

arcpy.RefreshActiveView()

arcpy.mapping.AddLayer(df, lyr1, "BOTTOM")

if add_legend=='true':

#styleItem = arcpy.mapping.ListStyleItems("USER_STYLE", "Legend Items", "NewDefaultLegendStyle")[0]

legend = arcpy.mapping.ListLayoutElements(mxd, "LEGEND_ELEMENT", "Legend")[0]

#legend.updateItem(lyr1, styleItem)

legend.autoAdd = True

del mxd

Above is the tool parameters you need to arrange..

Only thing that I could not figure out how to add legend itself with arcpy, so you need to manully create and empty legend before you run the script.

Re: How to add Legend to layer in ModelBuilder

NtriankosIoannis — Mon, 01 Sep 2014 10:09:16 GMT

Hi,

if this is just for symbology... right click in the model element (final output) -> properties -> layer symbology tab

Re: How to add Legend to layer in ModelBuilder

NaimeCelik — Mon, 01 Sep 2014 11:29:46 GMT

Actually, I think the question is about adding legend by using model builder to automate the process instead of doing it manually.. not sure how to add legend in model builder but you can create legend items after adding symbology in arcpy.. If you have any idea about how to add legend with model or script, I can also utilize from that..