Overwrite a hosted feature layer with new CSV

03-15-2021 11:39 AM
New Contributor II

I'm new to the esri community and would like to know if there is a way to overwrite the data in a hosted feature layer while retaining the layer definition. The issue I am running into is after I execute the python script to overwrite the existing layer, all of custom layer definitions, such as "drawingInfo", "maxRecordCount", and "typeIdFieldID", are set back to the default.

As a workaround, I attempted to retrieve the layer definition by retrieving the 'properties' of the feature layer and then using 'manager.update_definition' to re-establish the custom definition but when I do that I get 'TypeError: Object of type PropertyMap is not JSON serializable'

Any help would be appreciated.

Thank you

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5 Replies
Esri Contributor


Is it possible to share your script?

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New Contributor II

Yes....below is the code we are currently using the over write the feature layer:

--- Grab the properties of the point layer from the feature layer

gis = GIS("https://YOUR.arcgis.com",'USERNAME', 'PASSWORD')
search_results = gis.content.search('title: THE_LAYER_TITLE','Feature Layer')
item = search_results[0]
the_point_layer = item.layers[0]
the_properties = the_point_layer.properties

--- Over write the feature layer
from arcgis.features.managers import FeatureLayerCollectionManager
the_flc = FeatureLayerCollectionManager.fromitem(item)

--- Attempt to update the Feature Definition with the properties retrieved from the point layer prior to over writing the layer
the_point_layer.manager.update_definition({'properties': the_properties})

The code above produces the following error message:

'TypeError: Object of type PropertyMap is not JSON serializable'

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Esri Contributor

have a try with: 


the_point_layer.manager.update_definition({'properties': json.dumps( the_properties}))

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New Contributor II

Hi Minbin:

I appreciate your time and help. 

When I do this, I get the error:

TypeError: Object of type PropertyMap is not JSON serializable

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Occasional Contributor

It was the same for me.  It is getting confused here {'properties': the_properties}

In the update_definition method it will do a json.dumps trying to encode the dictionary {'properties': the_properties} to JSON.  The issue here is that the_properties is already a json_string, based on how it was retrieved, and in a json string you see json values like null, true, & false.  So when creating the dict {'properties': the_properties} you are creating a python dictionary with the key set to a json string. 

This confuses the process because json.dumps is looking for None, True, & False values instead of null, true, & false when encoding the string.

So, since the_properties is already a json string, what you want to do before calling the update_definition is convert the json string to a python dictionary or list of dictionaries whatever it may be. Get everything in a python format then pass it to the update_definition where it will encode the dictionary to a json string successfully.  At least this is what I have to do in a Jupyter Notebook.  It looks something like this:

# parsing _field_info creates a python dictionary, 
# where true=True, false=False, & null=None
json_string_to_dict = json.loads(f'{_field_info}')

# Create the update_dict
update_dict = {"fields": json_string_to_dict}

# Update the definition --> the update_definition method uses json.dumps
# to convert the python dictionary to json_string
result = feature_layer.manager.update_definition(update_dict)

 Or in your case:

json_string_to_dict = json.loads(f'{the_properties}')
dict_update = {"properties": json_string_to_dict}
result = feature_layer.manager.update_definition(dict_update)
- Justin Reynolds, PE
Senior GIS Analyst
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