Esri Web AppBuilder 2.4, Empty Basemap Gallery

I recently downloaded Web AppBuilder 2.4, Developer’s Edition and built a quick & dirty app. For some reason, it worked fine in Web AppBuilder but once I deployed it, no basemaps would show in the Baseman Gallery widget, it would just spin, spin, spin.

Digging around, I found some old posts where users were experiencing similar problems but none of the solution resulted in a great solution. I was able to get it to work by listing the basemaps individually in the config_BasemapGallery.json file but I that was more of a work-around. Notice in the thumbnailUrl, I have to put the full path to the thumbnails. Note that for brevity’s sake, I’m only showing one of the basemaps in this sample.

  "basemapGallery": {
    "showArcGISBasemaps": true,
    "basemaps": [{
      "layers": [{"url": ""}],
      "title": "Imagery",
      "thumbnailUrl": "http://<org><id>/info/thumbnail/tempimagery.jpg",
      "spatialReference": {
         "wkid": "102100"

Eventually, I started comparing the requests generated by the version in the development version and the one in production and tracked the problem down to this POST request in production, which was returning a 400 Bad Request error:


To this one in dev:


I stripped off the “&wab_dv=2.4” parameter from the production request and Boom! it worked. So I now knew what was causing the problem. Just had to figure out why it was occurring. I had actually already seen part of the answer while digging around in env.js while looking for a way to test my changes without having to clear my cache or remember to use an Incognito session. On line 81 of env.js, there is this variable, deployVersion which is set to 2.4.

I had recently worked on a solution that involved appending a time stamp onto scripts we were loading so I was familiar with what is going on–the code was appending a version onto the call so that if you change the deployVersion, the browser would load a new version of the code. The appendDeployVersion function on line 307 of env.js was doing the append. Notice the if statement on line 312, it checks for “?” in the url. If it finds one, it appends “&wab_dv=” and the version, otherwise it appends “?wab_dv=” and the version–the difference being the “&” vs “?”. A question mark is used before the first parameter in an URL, each additional parameter is separated by a ampersand (&) so that logic makes sense.

However, the monkey wrench is that I’m using a proxy, so my URL has a question mark related to the proxy:


So the code was dutifully appending an ampersand and the version parameter “&wab_dv=2.4” to my URL so the proxy would be requesting:


when it should have been requesting:


Once I had determined the problem (99% of the battle), I was able to quickly put in a patch that works for my instance. This patch isn’t a great one that Esri should use but it solves it in my case. I just added logic so that it would ignore proxy-related question marks:

function appendDeployVersion(url){
    if(/^http(s)?:\/\//.test(url) || /^\/proxy\.js/.test(url) || /^\/\//.test(url)){
      return url;

	var proxyURL = url.toLowerCase().replace(".ashx?","");
    if(proxyURL.indexOf('?') > -1){
      url = url + '&wab_dv=' + deployVersion;
      url = url + '?wab_dv=' + deployVersion;
    return url;

And voila! my Web AppBuilder now had all the basemaps options a mapineer could hope for:

Converting MXD to Layer file in Arcpy

Working on doing some advanced ArcGIS server printing and had the need to batch convert many existing .mxd files to .lyr files. So instead of opening up X number of map documents, thought I would do it via code. All of my .mxds in this case had just one data frame so the process was pretty simple–I add an empty group layer (Thanks Petr Krebs for the idea), copy all the existing layers into it, and save it out as a layer file.

I created an ArcGIS toolbox with two options–one to convert a single .mxd and one to batch convert an entire folder. To use it, make sure to have the EmptyGroup.lyr in the same directory as the .py file.

Here is the raw code or git it:

import os
import arcpy
import inspect
import glob
import uuid
import inspect

codeDir = os.path.dirname(inspect.getfile(inspect.currentframe()))
EmptyGroupLayerFile = codeDir+"/EmptyGroup.lyr"
inArg1 = sys.argv[1]
inArg2 = sys.argv[2]

def printit(inMessage):

def makeLyrFromMXD(inMXD, outLyr):
    if not (os.path.exists(inMXD)):
        printit( "ERROR: {} does not exist".format(inMXD))
        return False
    if not (os.path.exists(EmptyGroupLayerFile)):
        printit( "ERROR: {} does not exist".format(EmptyGroupLayerFile))
        return False
    if  (os.path.exists(outLyr)):
        printit( "Skipping: {} already exists".format(outLyr))
        return True

    printit( "Making Layer file: {0}".format(outLyr))

    mxd = arcpy.mapping.MapDocument(inMXD)
    ###Right now, just doing the first Dataframe, this could be modified
    df = arcpy.mapping.ListDataFrames(mxd)[0]

    theUUID = str(uuid.uuid1())

    iGroupLayerRaw = arcpy.mapping.Layer(EmptyGroupLayerFile) = theUUID
    groupBaseName = os.path.basename(outLyr).split(".")[0]

    for lyr in arcpy.mapping.ListLayers(df):
        if not ( == theUUID):
            if (lyr.longName ==
                arcpy.mapping.AddLayerToGroup (df, iGroupLayer, lyr, "Bottom")
            iGroupLayer = lyr = groupBaseName
    arcpy.SaveToLayerFile_management(iGroupLayer, outLyr)
    return os.path.exists(outLyr)

def doMultiple(inDir,outDir):
    for iMxd in glob.glob(inDir+"/*.mxd"):
        lyrFile = outDir+"/"+os.path.basename(iMxd).lower().replace(".mxd",".lyr")
        makeLyrFromMXD(iMxd, lyrFile)

if(not os.path.exists(EmptyGroupLayerFile)):
    printit("Error: {} is missing, can not run.".format(EmptyGroupLayerFile))
    if (os.path.isdir(inArg1) and (os.path.isdir(inArg2))):
    elif (os.path.isfile(inArg1)):
        if (os.path.exists(inArg2)):
            printit("Error: {} already exists".format(inArg2))
        printit("Unable to understand input parameters")

Calling os.startfile and from ArcGIS.

Recently I’ve created Python add-ins for data entry for our staff. Most of these have a toolbar with a “Help” button that opens a help file in .pdf format.

Sample python add-in toolbar.
Sample python add-in toolbar.

The first add-in was for ArcCatalog and this worked splendidly. I was using os.startfile(path to help.pdf).

However, when I started doing ArcMap add-ins, clicking the Help button would open the help.pdf but ArcMap would crash. Oops!

Luckily the Python development team at Esri already had a blog post about this at their ArcPy Café blog.

They report that the root of the problem is “conflicts in the way the Windows libraries expect to be called, they can fail or crash when called within ArcGIS for Desktop in an add-in script or geoprocessing script tool”. But this can be overcome by using a decorator function that calls os.startfile from a new thread. Another function effected by these conflicts is

Example code is shown below:

import functools
import os
import threading
import webbrowser
# A decorator that will run its wrapped function in a new thread
def run_in_other_thread(function):
    # functool.wraps will copy over the docstring and some other metadata
    # from the original function
    def fn_(*args, **kwargs):
        thread = threading.Thread(target=function, args=args, kwargs=kwargs)
    return fn_
# Our new wrapped versions of os.startfile and
startfile = run_in_other_thread(os.startfile)
openbrowser = run_in_other_thread(

Then whenever you call startfile or openbrowser, it will be routed through your decorator function and, as far as I’ve been able to tell, works fine without crashing your ArcMap session.


Quick & Dirty Arcpy: Verify a Coded Value Domain Code

I’ve been working on a few different data import routines and one of the things I recently built was the ability to verify that a potential Code to be entered into a field with a Coded Value Domain is valid.

The logic of the code is pretty straight-forward. Get a field’s domain and check that a potential value is one of the code values. The biggest “trick” in this code is that arcpy.da.ListDomains, which locates a field’s domain, takes a geodatabase (or Enterprise geodatabase connection file) as its only parameter. The documentation says it takes a workspace, but it does not like a feature dataset, which a feature class might be in.

A couple caveats about the code. It only returns True if a field exists, has a coded value domain, and the value tested is one of the (case-sensitive) valid codes. While I have an ArcToolbox tool to call it for illustration purposes, I’m only calling it from code so I wanted tight requirements.

Anyhow, here is the code or download it from GitHub.

import arcpy

inFeatureClass = sys.argv[1]
inField = sys.argv[2]
inValue = sys.argv[3]

# getFeatureClassParentWorkspace: This script gets the geodatabase for a
# feature class. The trick here is that feature classes can be within a
# feature dataset so you need to account for two possible levels in the
# directory structure.
def getFeatureClassParentWorkspace(inFeatureClass):
    describeFC = arcpy.Describe(inFeatureClass)
    if (describeFC.dataType == 'FeatureClass') or (describeFC.dataType == 'Table'):
        workspace1 = describeFC.path
        describeWorkspace1 = arcpy.Describe(workspace1)
        if (describeWorkspace1.dataType == 'FeatureDataset'):
            return describeWorkspace1.path
        return workspace1

    return None

# Find a field within a feature class
def getField(inFeatureClass, inFieldName):
  fieldList = arcpy.ListFields(inFeatureClass)
  for iField in fieldList:
    if == inFieldName.lower():
      return iField
  return None

#Get a field's domain
def getDomain(inFeatureClass, inField):
    theField = getField(inFeatureClass,inField)
    if (theField <> None):
        searchDomainName = theField.domain
        if (searchDomainName <> ""):
            for iDomain in arcpy.da.ListDomains(getFeatureClassParentWorkspace(inFeatureClass)):
                if == searchDomainName:
                    return iDomain
    return None

#Get the domain.
def validDomainValue(inFeatureClass,inField,inValue):
    theDomain = getDomain(inFeatureClass,inField)

    if not (theDomain is None):
        if (theDomain.domainType == "CodedValue"):
            if theDomain.codedValues.has_key(inValue):
                return True
    return False

if (validDomainValue(inFeatureClass,inField,inValue)):
    arcpy.AddMessage("Value ({0}) is valid for field [{1}].".format(inValue,inField))
    arcpy.AddError("ERROR: Value ({0}) is invalid for field [{1}].".format(inValue,inField))

Quick & Dirty ArcPy: Listing Data Sources

I just had the need to go through a directory containing many (100+) layer files (.lyr) and verify the data sources in each. I could have loaded each into ArcMap and checked the properties, but choose not to. Here’s the bare-bones script I used instead:

import arcpy, glob,os

theDir = r"L:\gdrs\data\org\us_mn_state_dnr\elev_minnesota_lidar\\"

for iFile in glob.glob("*.lyr"):
    print iFile
    lyr = arcpy.mapping.Layer(iFile)
    for i in arcpy.mapping.ListLayers(lyr):
            print "    {0}: {1}".format(i,i.dataSource)
            print "    {0}: Does not support dataSource".format(i)

print "Done!"

Quick & Dirty arcpy: Compare Feature Class Table Schemas

I’m in the process of rewriting a process, moving most of the processing from arcpy to postgresql-enabled python (love me some psycopg2).

One of the QC checks I’m doing at the end of this re-write is just verifying that the feature class schemas are the same (or that the differences are intended)  under the new process as they were in the old process.

And while ArcGIS does have a good tool for this, there were a couple tweaks I wanted to make. Most notably, I wanted a list of fields that are not in both feature classes.

ArcGIS Table Compare

So I made a quick & dirty script to do that, nothing especially clever but I’ve found it useful. Download it from GitHub. I have it currently set up to work on feature layers but you should be able to change the toolbox parameter types to allow feature classes or tables.

import arcpy,sys,os

def printit(inMessage):
    print inMessage

featureclass1 = sys.argv[1]
featureclass2 = sys.argv[2]

tableheaders = 'name, type, width, precision, domain'

def makeFieldDict(inFC):
    d = arcpy.Describe(inFC)
    printit("Dataset: "+d.baseName)
    printit("Type: "+d.dataType)
    printit("Path: "+d.catalogPath)
    printit(" ")


    printit (tableheaders)
    fieldDict = dict()
    printit (lFields)
    for lf in lFields:
        fieldDict[] = [,lf.type,lf.length,lf.precision,lf.domain]
        printit (", "+lf.type +", "+str(lf.length)+", "+str(lf.precision)+", "+lf.domain)
    return fieldDict

fieldDict1 = makeFieldDict(featureclass1)
fieldDict2 = makeFieldDict(featureclass2)
errorList = []
printit(" ")
printit(" ")
printit("Comparing Fields:")
for iField in sorted(list(set(fieldDict1.keys()+fieldDict2.keys()))):
    if not (fieldDict1.has_key(iField)):
        theResult = " {0} not found in {1}".format(iField,featureclass1)
    elif not (fieldDict2.has_key(iField)):
        theResult = " {0} not found in {1}".format(iField,featureclass2)
        if (fieldDict1[iField] == fieldDict2[iField]):
            theResult = " {0} OK".format(iField)
            theResult = " {0} Have Different Definitions \n   {1}: {2}\n   {3}: {4}".format(iField,featureclass1,fieldDict1[iField],featureclass2,fieldDict2[iField])

    printit( theResult )

printit(" ")
printit(" ")
if len(errorList) == 0:
    printit("GOOD! No difference Found!")
    printit("These Differences Found:")
    for iError in errorList:


Garmin GPX to Shapefile (SHP) conversion

I mentioned using Tapiriik to batch download my entire Garmin Connect history–over 1,000 separate .GPX files. I found several tools to convert .GPX to shapefiles that worked but none seemed to recognize my heart rate data.

The trick is Garmin extends the GPX specification to incorporate the heart rate:


Each track point looks like this:

     <trkpt lat=”43.68346489146352″ lon=”-92.99583793468773″>


Since the first few exiting GPX converters failed to meet my needs, I decided to make my own, at least partially.

I used Joel Lawhead of‘s pyshp library to handle writing the shapefile. I added some basic loop and I stuck a template.prj in the workspace that gets copied once for each shapefile.

Otherwise, nothing too fancy going on.  The code can be downloaded from Github.

import glob, os
import xml.etree.ElementTree as ET
import shapefile
import shutil

theNS = "{}".lower()
theNS2 = "{}".lower()
templatePRJfile = "template.prj"

def elementIs(inElement,inTag):
    item1 = inTag.lower()
    item2 = elementName(inElement)
    return (inTag.lower() == elementName(inElement).lower())

def elementName(inElement):
    item1= inElement.tag.lower().replace(theNS,"").replace(theNS2,"")
    return item1

def convertTimeToSeconds(inTime):
    theSeconds = -1

    if (inTime.count(":")) == 2:
            inHour = inTime.split(":")[0]
            inMin = inTime.split(":")[1]
            inSec = inTime.split(":")[2]

            totalSec = float(inSec)
            totalSec += (float(inMin) * 60)
            totalSec += (float(inHour) * 3600)
            theSeconds = totalSec

    return theSeconds

def writeSHP(inSourceFile,inTrkList):
    w = shapefile.Writer(shapefile.POINT)

    iTrkSegIndex = 0
    startSec =-1
    prevSec = -1
    for iTrkSeg in inTrkList:
        iTrkPtIndex = 0
        for iTrkPtDict in iTrkSeg:
            thisLine = "{0},{1},{2},*time*,*ele*,*hr*,*lat*,*lon*".format(inSourceFile,iTrkSegIndex,iTrkPtIndex)

            theLat = None
            if (iTrkPtDict.has_key('lat')):
                    theLat = float(iTrkPtDict['lat'])

            theLon = None

            if (iTrkPtDict.has_key('lon')):
                    theLon = float(iTrkPtDict['lon'])

            theDate = None
            theTime = None
            theSeconds = -1
            segSeconds = -1
            totSeconds = -1

            if (iTrkPtDict.has_key('time')):
                theDateTime = iTrkPtDict['time']
                if ("T" in theDateTime):
                    theDate = theDateTime.split("T")[0]
                    theTimePlue = theDateTime.split("T")[1]
                    if ("+" in theTimePlue):
                        theTime = theTimePlue.split("+")[0]
                        theSeconds = convertTimeToSeconds(theTime)

                        if (prevSec < 0):
                            prevSec = theSeconds
                        if (startSec<0):
                            startSec = theSeconds

                        segSeconds = theSeconds - prevSec
                        prevSec = theSeconds
                        totSeconds = theSeconds - startSec
                theDateTime = None

            if (iTrkPtDict.has_key('ele')):
                theElev = iTrkPtDict['ele']
                theElev = None

            if (iTrkPtDict.has_key('hr')):
                theHR = iTrkPtDict['hr']
                theHR = None

            if (iTrkPtIndex == len(iTrkSeg) - 1):
                theLast = 1
                theLast = 0

            w.point(theLon, theLat)

                print "############## ERROR ####################"

    w = None
    if (os.path.exists(templatePRJfile)):
        newPRJFN = inSourceFile.lower().replace(".gpx",".prj")

def mainLoop():
    for iFile in glob.glob("*.gpx"):
        print iFile
        tree = ET.parse(iFile)

        theTrkList = []

        for iRoot in root:
            if elementIs(iRoot,"trk"): #"}trk" in iRoot.tag.lower():
                for iTrkSeg in iRoot:
                    if not elementIs(iTrkSeg,"trkseg"):
                    thisTrk = []

                    pntIndex = 0
                    for iTrkPt in iTrkSeg:
                        if not elementIs(iTrkPt,"trkpt"):
                        trkPntDict = dict()
                        trkPntDict["pntIndex"] = pntIndex
                        trkPntDict['lat'] = iTrkPt.get('lat')
                        trkPntDict['lon'] = iTrkPt.get('lon')

                        for iElem in iTrkPt:
                            if elementIs(iElem,"extensions"):
                                for iSubElem in iElem:
                                    if (elementIs(iSubElem,"TrackPointExtension")):
                                        for iExtensionElem in iSubElem:
                                            if elementIs(iExtensionElem,"hr"):
                                                trkPntDict[elementName(iExtensionElem)] = iExtensionElem.text
                                trkPntDict[elementName(iElem)] = iElem.text

                        #print trkPntDict

        writeSHP(iFile.lower(), theTrkList)

theLineList = mainLoop()


Zipping a Shapefile from ArcCatalog

Back in 2010, I posted a python script and an ArcToolbox tool for zipping a shapefile.

Well, I had a request to modify the code so it would not error out if it encounters a .lock file. While .lock files exist for a reason and shouldn’t be totally ignored, in some cases it is safe to do so, so I went ahead any modified the code, which can be downloaded from Github.

The guts of the code is here, though:

import zipfile
import sys
import os
import glob

theShapeFile = sys.argv[1]
outputZipFile = sys.argv[2]
skipLockFile = sys.argv[3]

def zipShapefile(inShapefile, newZipFN, skipLockFile):
    print 'Starting to Zip '+inShapefile+' to '+newZipFN

    if not (os.path.exists(inShapefile)):
        print inShapefile + ' Does Not Exist'
        return False

    if (os.path.exists(newZipFN)):
        print 'Deleting '+newZipFN

        if (os.path.exists(newZipFN)):
            print 'Unable to Delete'+newZipFN
            return False

    zipobj = zipfile.ZipFile(newZipFN,'w')

    for infile in glob.glob( inShapefile.lower().replace(".shp",".*")):
        print infile
        if not ((os.path.splitext(infile.lower())[1] == ".lock") and (skipLockFile.lower() == "true")):


    return True

print "done!"