ArcXML/ArcIMS equivalents in python/arcpy - creating points and lines

[DavidChevrier]

I need to update an old script that uses ArcIMS and ArcXML into modern day python and arcpy.  This script runs in perl, but the part I need to recreate has to do with creating graphics layers on the fly.  Given some lat/longs, how do I create them as points, then draw lines between them, and then symbolize them how I want?

In perl, I create the xml I want, then send it to the server pretty easily as seen below:

In this code I create the points and lines based on an array of lat/longs

Then I send the request to the arcims server which is hosting a basemap that these are drawn on and export a jpeg:

This seems much harder than it should be in python.  The script I've come up with so far is below.  It creates a points layer and adds it to an existing map (which works fine), but I cant change the symbols.  Basically I just want to use a text letter for each point.  The other tricky part will be creating the lines from it.  I will use the script and tool in arctoolbox, but this is really a ton more work and I still don't know how to change the symbols.  The only idea I came up with is to add a dummy layer that is symbolized how I want but turned off, then apply that symbology to the newly created letters.  But that won't give me the dynamic creation I need.  (These scripts do a bunch more, I just tried to simplify it here.)  At the end it exports a jpeg of the map.

import arcpy

import os

import uuid

arcpy.env.overwriteOutput = True

templateMxd = r"C:\location\to\my\mxd.mxd"

mxd = arcpy.mapping.MapDocument(templateMxd)

# list of lat/longs

ptList = [[-82.1, 29.51], [-80.07, 31.13], [-82.97, 31.96], [-86.12, 27.71], [-82.9, 25.25]]

pt = arcpy.Point()

ptGeoms = []

for p in ptList:

    pt.X = p[0]

    pt.Y = p[1]

    ptGeoms.append(arcpy.PointGeometry(pt))

tempPoints = os.path.join(arcpy.env.scratchGDB, 'tempPoints')

arcpy.env.workspace = arcpy.env.scratchFolder

arcpy.CopyFeatures_management(ptGeoms, tempPoints)

arcpy.MakeFeatureLayer_management(tempPoints, "Start_Points")

arcpy.SaveToLayerFile_management("Start_Points", "Start_Points.lyr")

tempPointsLayer = os.path.join(arcpy.env.scratchFolder, 'Start_Points.lyr')

addLayer = arcpy.mapping.Layer(tempPointsLayer)

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

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

lyrExtent = addLayer.getSelectedExtent()

df.extent = lyrExtent

output = 'WebMap_{}.jpg'.format(str(uuid.uuid1()))

Output_File = os.path.join(arcpy.env.scratchFolder, output)

# Export the WebMap

arcpy.mapping.ExportToJPEG(mxd, Output_File, df, df_export_width=500, df_export_height=500, resolution=150)

# Set the output parameter to be the output file of the server job

arcpy.SetParameterAsText(1, Output_File)

del mxd, addLayer, lyr

[DarrenWiens2]

I think you can achieve this by using an InsertCursor to create the point geometries plus an attribute for the letter, rather than the list/CopyFeatures method. Your insert cursor would use fields like: ['LETTER', 'SHAPE@XY']

As you suggest, you'd need a layer symbolized as you'd like, but I think this would be best done with no symbol and labeling the point with the letter.

[DavidChevrier]

Thanks!  That will help with the table create and running the tools I need.  Any idea about changing the symbology after I add the points to the map to be a letter rather than the default circle?

[DarrenWiens2 · Accepted solution]

I would add the letter as an attribute and label rather than symbolize. So, if the letter in the attribute for a feature was "P" it would be labeled as "P". Do you have a more complex symbol in mind, like a letter on top of a circle or something?

[DavidChevrier]

Can't believe I hadn't thought of that...  thank you!!  One last question though, how do I remove the default symbol it will give me?  Just make a dummy layer in the map with no symbology and assign my new point layer to that?  I still need to know how to change the symbology of the line layer that is created with this script 2.

[DavidChevrier]

For the line symbol, it is a basic line, I just need to assign them different colors in code

[DarrenWiens2]

Just make a dummy layer in the map with no symbology and assign my new point layer to that?

Yes, you can switch data source of your dummy layer ​to your new layer using the replaceDataSource method.

I'm not sure how to dynamically color your new lines. You may want to open a new question for that.