Esri Web AppBuilder 2.4, Empty Basemap Gallery Follow-Up

A while ago I posted a work-around for a problem I was having with a Web AppBuilder application. Working with Esri tech support, we determined what I was doing to cause the problem.

In my config.json, I was using a relative path to the proxy. Note that I had the proxy as a separate application at the root level of our domain because I intended to have a shared proxy for all of our applications instead of individual ones. So the WAB application would be using http://ourarcgisdomain.com/proxy/proxy.ashx.

   "httpProxy": {
	"useProxy": true,
	"alwaysUseProxy": true,
    "url": "/proxy/proxy.ashx",
    "rules": []
  }

Well, that was causing the hiccup in the Basemap Gallery Widget. I simply modified the url parameter to have the full path of our domain, undid my custom code, and the Basemap Gallery Widget was happy.

  "httpProxy": {
     "useProxy": true,
     "alwaysUseProxy": true,
     "url": "http://ourarcgisdomain.com/proxy/proxy.ashx",
     "rules": []
   }

Score one for Esri Tech Support.

Although, in my defense the documentation on the configuring the proxy is silent on the pathing.

 

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):
    arcpy.AddMessage(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)
    iGroupLayerRaw.name = theUUID
    arcpy.mapping.AddLayer(df,iGroupLayerRaw,"TOP")
    groupBaseName = os.path.basename(outLyr).split(".")[0]

    for lyr in arcpy.mapping.ListLayers(df):
        if not (lyr.name == theUUID):
            if (lyr.longName == lyr.name):
                arcpy.mapping.AddLayerToGroup (df, iGroupLayer, lyr, "Bottom")
        else:
            iGroupLayer = lyr

    iGroupLayer.name = 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))
else:
    if (os.path.isdir(inArg1) and (os.path.isdir(inArg2))):
        doMultiple(inArg1,inArg2)
    elif (os.path.isfile(inArg1)):
        if (os.path.exists(inArg2)):
            printit("Error: {} already exists".format(inArg2))
        else:
            makeLyrFromMXD(inArg1,inArg2)
    else:
        printit("Unable to understand input parameters")

Calling os.startfile and webbrowser.open 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 webbrowser.open.

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
    @functools.wraps(function)
    def fn_(*args, **kwargs):
        thread = threading.Thread(target=function, args=args, kwargs=kwargs)
        thread.start()
        thread.join()
    return fn_
 
# Our new wrapped versions of os.startfile and webbrowser.open
startfile = run_in_other_thread(os.startfile)
openbrowser = run_in_other_thread(webbrowser.open)

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.

Cheers!

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\\"
os.chdir(theDir)

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

print "Done!"

SDEINTERCEPT & SDEINTERCEPTLOC

Awhile ago, I had a ArcSDE problem that required ESRI technical support to help trouble-shoot. The problem was odd but was resolved by rebooting the server.
During the process, though, the support person had me set a couple of environment variables for logging SDE activity on the client machine.

The settings were SDEINTERCEPT and SDEINTERCEPTLOC.

From ESRI’s Help, SDEINTERCEPT specifies what activity to log and SDEINTERCEPTLOC specifies where to save the log files.

I recently deleted the directory I made for the log files but did not remove the variables and I noticed that one of my python scripts reported a weird error (but continued to run, I think). I tracked it back to these variables and realized what I had done.

Googling SDEINTERCEPTLOC did lead me to some helpful information like:

The SDEINTERCEPT blog where Ken posts ArcSDE help.

This ESRI post about troubleshotting geoprocessing problems.

And this ESRI technical article about diagnosing ArcSDE Connections.

Checking to see if a Field Index Exists Using Arcpy (ArGIS 10.0) redux

I’ve previously posted python code to check if a field index exists for both ArcGIs 9.3 and ArcGIS 10.0.

Recently I have been working on a process that was using this code but it was not working because it looks for an index with a specific name.  It was not working in this case because the name of the indexes was getting incremented as they were being created.  For example, I was building an index on the table C5ST, field RelateId ([C5IX].[Relateid]) named I_C5IX_RelateId.  That worked fine until we switched our process so now we keep multiple versions of some tables, each with a date-based suffix.

We now have tables name C5St_20110625 and C5St_20110626–the Index-name scheme, however was still creating I_C5IX_RelateId and it worked great on the first one.  But when it created the second one, even on a different table, it was automatically name I_C5IX_RelateId_2 even though the name I_C5IX_RelateId was used when trying to create the index.

Before generating relates, our code checks to see if the key fields are indexed, and if they are not, builds  an index.  Because of the naming situation, multiple, duplicate indexes were being created.  Probably not too harmful but it is a little messy.

So I re-wrote the code so that you pass the function the table name and field name that you want to check and it checks to see if there is an index existing for that field and return a Boolean.  The one little wrinkle I put in is to account for indexes that span multiple fields–the ” if (iIndex.fields[0].Name.upper() == fieldname.upper()):” statement is checking the index to see if it is on a single field or multiple fields.

 

def fieldHasIndex(tablename,fieldname):
if not arcpy.Exists(tablename):
return False

tabledescription = arcpy.Describe(tablename)

for iIndex in tabledescription.indexes:
if (len(iIndex.fields)==1):
if (iIndex.fields[0].Name.upper() == fieldname.upper()):
return True

return False

Feature classes and Tables with names starting with “nd_”.

Random luck me to discovering a bug related to feature classes whose names start with “nd_”.  It appears that you are allowed to create feature classes starting with “nd_” but ArcCatalog will not display them.  Further research shows this behavior also occurs for table and for ArcSDE (PostGres) geodatabases,  personal geodatabase, and file geodatabases–I am using ArcCatalog 10.0.

I first noticed something odd was occurring while importing a series of shapefiles into a geodatabases.  After importing 15 shapefiles, I only had thirteen feature classes despite receiving no errors during the process.  The two shapefiles that failed to import were named ND_oil_and_gas.shp and ND_Bendix_Study.shp.  Subsequent attempts to import them individually returned an error “Invalid Target Name”.

I discovered in pgAdmin III (Postgres SDE Geodatabase) that the table existed and there was an entry in sde.sde_layers for the feature class but ArcCatalog refused to show it.

I used some un-supported methods to try to resolve the problem and despite some sweating, I failed to find a way to get ArcCatalog to display these feature classes.  I did, however, at least found a way to delete them–arcpy can detect that the feature classes exists so it is able to delete them.

At least by deleting them, I can prevent leaving “invisible” feature classes from hanging out in my geodatabase.

I suspect the problems stems from how ESRI has implemented the Network dataset table-naming structure –dirty areas are stored in tables named nd_<itemid>_dirtyareas  and nd_<itemid>_dirtyobjects.  Possibly the developer  working on the ArcCatalog GUI ended up suppressing showing feature classes and tables whose names start with “nd_”.

And, just for posterity’s sake, here is a python code snippet listing the feature classes in a workspace:

import arcpy

arcpy.env.workspace = “c:/temp/_nd/F.gdb”

print arcpy.env.workspace
for fc in arcpy.ListFeatureClasses():
print fc

print “Done!”

Renaming Raster Dataset and arcpy.Exists()

Discovered something today. I was working on an arcpy script that copies a raster dataset from a file geodatabase into a Postgres SDE geodatabase and then does some boring routine tasks–building stats, creating a mosaic dataset, adding the raster to the mosaic dataset and making a couple referenced mosaic datasets.

It sometimes has trouble with the initial step of uploading the raster because of the sheer size of if (1m elevation raster for counties) and it failed today on one. It failed today so I used the ArcCatalog GUI to copy the raster and renamed it.

I then proceeded to run launch my script. Before each step, I use arcpy.Exists() extensively to check to see if various items exist before I attempt to create them. It was continuously reporting that my raster set did not exist even though I could see it in ArcCatalog.

Finally, I realized that I needed to close ArcCatalog before arcpy recognized the fact I had renamed something. To note, I was running arcpy from a separate PythonWin window, not from the ArcCatalog session I had renamed the raster dataset with.

Once I closed ArcCatalog, arcpy recognized the renaming and life was good.

I’m also suspicious now about a problem I often have running statistics on my rasters.  The ArcTool reports no errors when I create them but for some reason the raster does not show that it has statistics afterwards.  I normally have multiple ArcApplication sessions open and now suspect that perhaps this problem is due to sessions not letting go of the connection.  Stay tuned for further developments on this.

Quick & Dirty arcpy: Batch Splitting Polylines to a Specific Length.

For some odd reason, I wanted to split all the arcs in a polyline feature class to a specific length–if a specific feature was longer than the target length, it would become two or more separate polyline records.

Here is the bare-bones script that copies an existing feature class into a new feature class then processes each record, splitting it into multiple records if the polyline is longer than the user-specified tolerance.  Some cautionary notes:

  • This is Quick & Dirty code–minimal error catching or documentation.
  • I basically tested this against one feature class (the one I wanted to split) once I got it to work, I quit.
  • There is some rounding error–features may be a tad bit off (a few ten-thousandths of a unit).
  • I did not test against multi-part features.
  • The tolerance is the native units of the data–if your data is in meters but you want to split the polylines every mile, enter 1,609.344.

I have included both a toolbox file (.tbx) and python script (.py).  After loading the toolbox, you’ll have to change the Source of the script by right-clicking on it, selecting the Source tab, and then navigating to the .py file.

Here is the code for the Googlebots, but you are better off just downloading it.

import arcpy
import sys, math

def printit(inMessage):
    print inMessage
    arcpy.AddMessage(inMessage)

if len(sys.argv) > 1:
    inFC = sys.argv[1]
    outFC = sys.argv[2]
    alongDistin = sys.argv[3]
    alongDist = float(alongDistin)
else:
    inFC = "C:/temp/asdfasdf.mdb/jkl"
    OutDir = "C:/temp/asdfasdf.mdb"
    outFCName = "jkl2d"
    outFC = OutDir+"/"+outFCName
    alongDist = 1000

if (arcpy.Exists(inFC)):
    print(inFC+" does exist")
else:
    print("Cancelling, "+inFC+" does not exist")
    sys.exit(0)

def distPoint(p1, p2):
    calc1 = p1.X - p2.X
    calc2 = p1.Y - p2.Y

    return math.sqrt((calc1**2)+(calc2**2))

def midpoint(prevpoint,nextpoint,targetDist,totalDist):
    newX = prevpoint.X + ((nextpoint.X - prevpoint.X) * (targetDist/totalDist))
    newY = prevpoint.Y + ((nextpoint.Y - prevpoint.Y) * (targetDist/totalDist))
    return arcpy.Point(newX, newY)

def splitShape(feat,splitDist):
    # Count the number of points in the current multipart feature
    #
    partcount = feat.partCount
    partnum = 0
    # Enter while loop for each part in the feature (if a singlepart feature
    # this will occur only once)
    #
    lineArray = arcpy.Array()

    while partnum < partcount:
        # Print the part number
        #
        #print "Part " + str(partnum) + ":"
        part = feat.getPart(partnum)
        #print part.count

        totalDist = 0

        pnt = part.next()
        pntcount = 0

        prevpoint = None
        shapelist = []

        # Enter while loop for each vertex
        #
        while pnt:

            if not (prevpoint is None):
                thisDist = distPoint(prevpoint,pnt)
                maxAdditionalDist = splitDist - totalDist

                print thisDist, totalDist, maxAdditionalDist

                if (totalDist+thisDist)> splitDist:
                    while(totalDist+thisDist) > splitDist:
                        maxAdditionalDist = splitDist - totalDist
                        #print thisDist, totalDist, maxAdditionalDist
                        newpoint = midpoint(prevpoint,pnt,maxAdditionalDist,thisDist)
                        lineArray.add(newpoint)
                        shapelist.append(lineArray)

                        lineArray = arcpy.Array()
                        lineArray.add(newpoint)
                        prevpoint = newpoint
                        thisDist = distPoint(prevpoint,pnt)
                        totalDist = 0

                    lineArray.add(pnt)
                    totalDist+=thisDist
                else:
                    totalDist+=thisDist
                    lineArray.add(pnt)
                    #shapelist.append(lineArray)
            else:
                lineArray.add(pnt)
                totalDist = 0

            prevpoint = pnt                
            pntcount += 1

            pnt = part.next()

            # If pnt is null, either the part is finished or there is an
            #   interior ring
            #
            if not pnt:
                pnt = part.next()
                if pnt:
                    print "Interior Ring:"
        partnum += 1

    if (lineArray.count > 1):
        shapelist.append(lineArray)

    return shapelist

if arcpy.Exists(outFC):
    arcpy.Delete_management(outFC)

arcpy.Copy_management(inFC,outFC)

#origDesc = arcpy.Describe(inFC)
#sR = origDesc.spatialReference

#revDesc = arcpy.Describe(outFC)
#revDesc.ShapeFieldName

deleterows = arcpy.UpdateCursor(outFC)
for iDRow in deleterows:       
     deleterows.deleteRow(iDRow)

del iDRow
del deleterows

inputRows = arcpy.SearchCursor(inFC)
outputRows = arcpy.InsertCursor(outFC)
fields = arcpy.ListFields(inFC)

numRecords = int(arcpy.GetCount_management(inFC).getOutput(0))
OnePercentThreshold = numRecords // 100

printit(numRecords)

iCounter = 0
iCounter2 = 0

for iInRow in inputRows:
    inGeom = iInRow.shape
    iCounter+=1
    iCounter2+=1    
    if (iCounter2 > (OnePercentThreshold+0)):
        printit("Processing Record "+str(iCounter) + " of "+ str(numRecords))
        iCounter2=0

    if (inGeom.length > alongDist):
        shapeList = splitShape(iInRow.shape,alongDist)

        for itmp in shapeList:
            newRow = outputRows.newRow()
            for ifield in fields:
                if (ifield.editable):
                    newRow.setValue(ifield.name,iInRow.getValue(ifield.name))
            newRow.shape = itmp
            outputRows.insertRow(newRow)
    else:
        outputRows.insertRow(iInRow)

del inputRows
del outputRows

printit("Done!")

Quick & Dirty arcpy: Field Listings

I have to often get a table structure for a feature class or table into either a spreadsheet or word processing document.  There might be an easy way to do this in ArcGIS 10 but I haven’t found it.  So, as is my nature, I decided to roll my own.

This is a bare-bones script that iterates through the fields, printing the field name, type, width, and precision.  There are three optional features to it:

  • You can choose to have it list the domain, if there is one, on each field.
  • You can have it write to a text file (otherwise you can just copy & paste the results from the results window).
  • You can have it count the number of populated records.  This can take a long time if working with a large dataset.  Also note that my logic for determining what constitutes being populated may not be what you need but the structure is there.  I also do not account for all field types, if the field is of a type I have not account for, the code will return -999.

To use the script from ArcToolbox, you need to pass it four parameters, their Names, type, whether they are input or output, and whether they are required or optional are:

  • featureclass, Table, Input, Required
  • includedomainstring, Boolean, Input, Required (controls whether or not domains are exported)
  • doCountsRespone, Boolean, Input, Required (controls whether or not you want to get the number of populated records.  (Your definition of populated may vary from my code)
  • outputFile, File, Output, Optional (optional output file to write)

Here is the code, but you are better off just downloading it since I haven’t figured out a good way to have WordPress play nicely with python’s indenting.

# Name: ListFields-arcpy.py
#
# Purpose: Lists the fields, their type, width, and precision
# Can either have it export it to a CSV file or copy
# and paste from the results window.
#
# To use, create a tool from the script and add 3 parameters:
#  1) Table, Input, Required
#  2) Boolean, Input, Required (controls whether or not domains are exported)
#  3) Boolean, Input, Rekquired (controls whether or not you want to get the number of
#  Populated records.&nbsp; (Your defintion of populated may vary from my code)
#  4) File, Output, Optional (optional output file to write)
#
#

import arcpy,sys,os

def printit(inMessage):
 print inMessage
 arcpy.AddMessage(inMessage)

if len(sys.argv) > 4:
 featureclass = sys.argv[1]
 includedomainstring = sys.argv[2]
 doCountsRespone = sys.argv[3]
 outputFile = sys.argv[4]
else:
 featureclass = "C:/temp/before.shp"
 includedomainstring = "false"
 doCountsRespone = "true"
 outputFile = "C:/temp/before.csv"

if (outputFile == ""):
 doOutputFile = False
else:
 doOutputFile = True

if (str(doCountsRespone).lower() == "true"):
 doCounts = True
else:
 doCounts = False

if (str(includedomainstring).lower() == "true"):
 includedomain = True
else:
 includedomain = False

lfields=arcpy.ListFields(featureclass)

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

tableheaders = 'name,type,width,precision'

if (doCounts == True):
 tableheaders+=",count"

if (includedomain == True):
 tableheaders+=",domain"

if (doOutputFile):
 tmpfile = open(outputFile,"w")
 tmpfile.write(tableheaders)
 tmpfile.write("n")

printit (tableheaders)
for lf in lfields:

 pThisline = lf.name+","+lf.type +","+str(lf.length)+","+str(lf.precision)

 if (doCounts == True):

 rowCount = 0

 #Note that I do not account for all field types
 #Also note that my definition of being populated may vary from yours.
 #I am using -999 as a flag to indicate a field type was not successfully
 #identified.
 if (lf.type == "Double") or (lf.type == "Single")&nbsp; or (lf.type == "Integer") or (lf.type == "SmallInteger"):
  queryString = '"'+lf.name + '" > 0'
  rows = arcpy.SearchCursor(featureclass, queryString, "", "", "")
 elif (lf.type == "String"):
  queryString = '"'+lf.name + '" <> ' + "''"
  rows = arcpy.SearchCursor(featureclass, queryString, "", "", "")
 else:
  rowCount = -999
  #rows = arcpy.SearchCursor(featureclass, "", "", "", "")

 if (rowCount == 0):
  for row in rows:
   rowCount+=1

 pThisline=pThisline+","+str(rowCount)

 if (includedomain == True):
  pThisline=pThisline+","+lf.domain

 printit (pThisline)

 if (doOutputFile):
  tmpfile.write(pThisline)
  tmpfile.write("n")

if (doOutputFile):
 tmpfile.close