Latest Contributions by KimOllivier

This is even tricky for polygons. Esri enforce a convention of outside clockwise with holes counterclockwise. This is the Right Hand Rule and defines which side of a polygon is UP. But OGC forgot to define this so lots of open tools do not enforce this rule causing spatial analysis errors. To standardise run the Repair Geometry Tool. Note all KML polygons will be corrupt after importing for example. But what about polylines? There is no convention here but often it matters, such as when labelling text, now more sophisticated thank goodness. But there is no From-To convention for polylines. Even finding the start and end nodes is no longer supported with 'shape files'. It was for coverages with built-in arc node topology. Someone could write a small python script to find the start and end points and the midpoint (all available functions) and then you need to do some clever vector geometry calculating the vector cross product to see if the polyline curves to the left or right. Then flip all required polylines. Another approach might be to close the start and end points temporarily to create polygons, then repair geometry, find the ones that have been reversed (repaired) and those are the source polylines that need flipping. You might be able to use Linear Referencing. When you define routes you nominate the corner of the extent for the start of each route. This makes all the routes run in the same direction. Not quite clockwise but directed. When calculating a convex hull of a cloud of points the boundary polyline is a clockwise polyline. Maybe you can adapt the very simple algorithm to achieve a similar result. Or make a convex hull and then order your data. Now I have thought that I don't really understand your question! A picture would help. Do you want all your polylines looking like a stream, or is each one independent? I am very curious as to why you need them flipped. ... View more

I have been starting to use the Python API  and I have found it very difficult to understand the functions. The samples are just 'showoff' examples of why you would use GIS, not how to debug the tools. I find that the arcpy documentation is much more helpful because there are example snippets on every function right in the help, not somewhere in a sample. The edit tools have 16 samples for the whole module. Most of the functions and parameters are not covered with an example anywhere. I cannot find a working example of extract_changes(). I note in the community noticeboard that there was a bug in 2020 where 'optional' parameter for the URI  were actually required. Has this changed? Let's see something working so I can backtrack to see why my environment is different. I thought the python Open API on Github would have the source for arcgis! Some hope there, it only has a smattering of examples that give a once over lightly of each module. My initial thought was that since there was a missing function where I was porting an arcpy script I would add one myself - open source, published... (I can see a child table separately from the parent table in the GUI, so why not in the API?)   ... View more

There is already a function to validate the SQL string built in to the API. Very straightforward. https://developers.arcgis.com/python/api-reference/arcgis.features.html#arcgis.features.FeatureLayer.validate_sql ... View more

I am searching for a working example of extract_changes() too. I cannot understand the error messages. I did see a post from 2020 where it does not accept defaults as documented, you have to add in the URI for example. ... View more

What you have to do is add in the arcgis module as well as arcpy. Then you can access AGOL tools which include the Geocoding Service. Or switch to the geocoding service direct from ArcGISPro. Thefunctions and  parameters are different but it is the same service ultimately, and will also cost credits. ... View more

The GlobalID is readonly and out of our control. Make a new field and save the ID to a new GUID field that you do have ownership. Then make up a dictionary of oldID to newID and change the foreign key in the attachment to point to the new one. Phew! ... View more

I am trying to do the same. My hope was that you might be able to do this with Arcade from a parent/child relation. Maybe you can. However it will be quite complex because you will need to allow for multiple child records and you will need to use the last record. So turn on EditTracking. I have then found it would be possible to update the parent feature with the latest record using the Python API by offloading all the hard work to Pandas. Get a list of visit records and find the latest date for each GUID that is a foreign key to the GlobalID. Now you have a dataframe of these records to update the main layer with whatever you want to calculate into a status field ready to be symbolised. Note the magic one-liner at line 24. This script was in Pro, so there are a few changes to get a featureset in AGOL using fl.query_related_records()   # excess WeedLocations fields joined when adding extra visit events will be cleaned up... # dictionary of field mappings so far from Visits_Table to WeedLocations visit_to_weed = { 'Guid_visits': 'GlobalID', # foreign key -> primary key 'EditDate_1':'DateVisitMadeFromLastVisit', # for latest date "WeedVisitStatus":'StatusFromLastVisit', # as inspected 'DifficultyChild':'DifficultyFromLastVisit', # as inspected 'VisitStage':'LatestVisitStage', # as inspected 'Area':'LatestArea' # as inspected } # extract the data required from the database Visits_Table, don't even need a primary key eg GlobalID # In the future we will put on a filter greater than the last update filter = '' #"""EditDate_1 > date '{}'""".format('2022-07-01') in_flds = list(visit_to_weed.keys()) # ['Guid_visits','EditDate_1','WeedVisitStatus','DifficultyChild','VisitStage','Area'] out_flds = list(visit_to_weed.values()) vdate =[row for row in arcpy.da.SearchCursor(visits,in_flds,filter)] print('vdate:',len(vdate)) # put in a pandas dataframe df = pd.DataFrame(vdate,columns=in_flds) # find the record with max edit date by visit and keep the other details all in one line! idx = df.groupby(['Guid_visits'])['EditDate_1'].transform(max) == df['EditDate_1'] # print(df[idx]) dVisit = df.set_index('Guid_visits').T.to_dict('list') # print(dVisit.get('{08125D4D-4725-4A26-BAC9-98BE7EF0784C}',"Missing")) # {08125D4D-4725-4A26-BAC9-98BE7EF0784C}, 2022-08-23 03:04:01.644000, None, None, None, NaN # Count visits for each location vguid = [row[0] for row in arcpy.da.SearchCursor(visits,['GUID_visits'], "GUID_visits is not NULL")] # dict of counts by GlobalID for updating vguid_counts = collections.Counter(vguid) # put counts in new field VisitCount for now if len(arcpy.ListFields(weeds,'VisitCount')) == 0: arcpy.management.AddField(weeds,'VisitCount','LONG') with arcpy.da.UpdateCursor(weeds, ['VisitCount'] + out_flds) as cur: n = 0 for row in cur: try: row[1] = vguid_counts[row[0]] if dVisit.get(row[0],None): row[2] = dVisit.get(row[0],None)[0] row[3] = dVisit.get(row[0],None)[1] row[4] = dVisit.get(row[0],None)[2] row[5] = dVisit.get(row[0],None)[3] row[6] = dVisit.get(row[0],None)[4] cur.updateRow(row) n+=1 except Exception as e: arcpy.AddMessage(row) arcpy.AddMessage(e) arcpy.AddMessage("Well Done, {} records updated".format(n))     ... View more

Yes you can! But as pointed out the performance is terrible and limited. So you have to precalculate it to be useful on a map. Even that is painful! I have the same problem. In my case the user wanted to move the visit records to a related child table and have the location table as the parent. But some records do not have a child. Since the foreign key (a horrible GUID) is the link to the GlobalID (a read-only GUID) I needed to add missing records in the location feature layer to the visit related layer. I did this in a prototype using relates in Pro, and then in an arcpy script using dictionaries. Because arcpy does not use relates (or the tools that do are not reliable). So it works a treat in Pro because you have da.Cursors, and georelational tables. But in AGOL you have a giant object that you have to query in single REST requests that have limits on the data returned. In my Pro example there is still some magic performed in Pandas. It finds the record with the latest date grouped by foreign key all ready to update the feature layer. My next strategy is to go to the Visit related table with a more direct query in AGOL.You can get all the Visit records slowly by the WeedLocation record using query_related_records(). It is slow and painful and the return is a json nested mess but Pandas can unpack it. This enables me to update the featurelayer attributes that are used for symbology.         # add missing visits # oh yeah, cannot use relates # use keyfiles # Creative Commons NZ 4.0 Kim Ollivier # 10 Sept 2022 import os import sys import collections import arcpy try: gdb = sys.argv[1] except IndexError: gdb = 'm:/project/econet/source9Sep/CAMS_weed.gdb' if not arcpy.Exists(gdb): raise IOError arcpy.env.workspace = gdb arcpy.env.overwriteOutput = True arcpy.AddMessage(gdb) # "Visits_Table", "GUID_visits" "WeedLocations", "ParentGuid" or "GlobalID" vguid = [row[0] for row in arcpy.da.SearchCursor('Visits_Table',['GUID_visits'], "GUID_visits is not NULL")] print('vguid:',len(vguid)) # dict of counts by GUID for inspection later vguid_counts = collections.Counter(vguid) sql = """GlobalID NOT IN {}""".format(tuple(vguid)) print(sql[0:60], ' ... ',sql[-42:]) arcpy.management.MakeFeatureLayer('Weedlocations','weed_no_visit_lay',sql) # use a fieldinfo to limit fields? arcpy.management.CopyRows('weed_no_visit_lay','Visit_extra') # this adds in my name as an editor?? print("extras",arcpy.management.GetCount('Visit_extra')) # maybe extract a dict and insert # # make a new visits table to allow repeated tests arcpy.management.Merge(['Visits_Table','Visit_extra'], 'Visits_Table_new',add_source="ADD_SOURCE_INFO") max_dates = {} for key, value in {r[0]:r[1] for r in 'Visits_Table'}.items(): max_dates.setdefault(value, set()).add(key) with arcpy.da.UpdateCursor('WeedLocations',['GlobalID','VisitCount']) as cur: for row in cur: row[1] = vguid_counts.get(row[0],None) cur.updateRow(row)             ... View more

The only workaround that I see often is to create a ParentGUID GUID field and copy the GlobalID first. Then you have to change the foreign key GUID to the new GlobalID with an update.Maybe a python script or the Python API. This has also been driving me mad. The GlobalID is like an OBJECTID - not yours, so the software decides if the feature is a new record ... View more

Sort of retired? Jack Dangermond hasn't! Covid lockdowns have made me virtually retired! ... View more

Here I am in 2022 with ArcGIS Pro 3.01 installed still looking to see why it does not work with a couple of simple file geodatabases! ... View more

A great supplement to the official documentation. I have been looking everywhere for an example just like this. I have one to many, so am looking forward to this simple change to see it working for me. ... View more

Wow! ... View more

  # zoom to selected features import arcpy p = arcpy.mp.ArcGISProject('CURRENT') m = p.listMaps()[0] mv = p.activeView # part of trail selected lay = m.listLayers('trail')[0] extent = mv.getLayerExtent(lay, True, True) mv.zoomToAllLayers(True,True)   Maybe this function was not available in 2017, but it is now in 2021 in version 2.8 or earlier. The trick is to realise that the extents are available in the MapView of the active Map. While looking for this I tried out using Bookmarks which are also available, maybe a nice way to store the extent of selections.   ... View more

"No answer was the stern reply" after a year, so I suppose sadly that there is no REST interface to webmaps, which is what I wanted to do to get a thumbnail using all the nice formatting in the webmap by someone else. ... View more