[GIS] Setting basemap layers of WebMap using ArcGIS Python API

arcgis-online-webmaparcgis-python-apibasemap

Using the ArcGIS Python API, I've create a WebMap and two Layers (one containing features, the other containing labels):

cbmt = WebMap()
cbmt_geometry_layer = Layer(url = <url of geometry layer>)
cbmt_text_layer = Layer(url = <url of text layer>)

I'd like to add both of these layers to the map as basemap layers, like you can in ArcGIS Online or Portal when adding layers to a web map. The WebMap.basemap property is read-only. Is there a property on the WebMap.add_layer() method that specifies to add layers as basemap layers?

xref: https://community.esri.com/thread/223790-how-to-set-the-basemap-layers-of-a-webmap-using-the-arcgis-python-api

Best Answer

I don't see any methods in the API that allow you to add / modify the basemap of a webmap.

You might be able to take the long-way-approach to solving this. You'll need have a webmap with your layers ready to be used (or create it using Python API). Then you could create a new webmap and pass in the previous webmap. It'll be added to the basemap of this new webmap. Once you have this created, you can call add (more operational layers) / save to finish the webmap. Yes, unfortunately in the end you're making new items instead of updating existing ones.

from arcgis.mapping import WebMap
from arcgis.gis import GIS

gis = GIS("https://www.arcgis.com", "user", "password")

#grab an existing webmap which will be used as a basemap (below finds dark gray)
darkGray = gis.content.search('title:dark', 
                                    outside_org=True, item_type='web map')[0]
#Create a new webmap, passing in your existing webmap. This will set it as the basemap.
newWM = WebMap(darkGray)
props = {'title':'My New Map',
             'snippet':'Map created using Python API ',
             'tags':['automation', 'map', 'python']}

#Save the webmap, setting the basic properties
newWM.save(props)

reference: https://esri.github.io/arcgis-python-api/apidoc/html/arcgis.mapping.html#webmap and https://developers.arcgis.com/python/sample-notebooks/using-and-updating-gis-content/

Related Solutions

[GIS] Adding WMS layer (basemap) to ArcGIS Javascript API

When you query a map service end point, the result is one image. That is what ArcGIS will consider as your layer.

From a WMS standpoint, you can generate that image using one or more layer from your WMS Service.

When referring to the doc on https://developers.arcgis.com/javascript/3/jsapi/wmslayer-amd.html#wmslayer1, this is what you see at the definition of the constructor: new WMSLayer(url, options?)

In the following example: https://developers.arcgis.com/javascript/3/jssamples/layers_wmsresourceinfo.html

The following is the info (options parameter)from your WMS Service you choose to display:

  var layer1 = new WMSLayerInfo({
    name: '1',
    title: 'Rivers'
  });
  var layer2 = new WMSLayerInfo({
    name: '2',
    title: 'Cities'
  });
  var resourceInfo = {
    extent: new Extent(-126.40869140625, 31.025390625, -109.66552734375, 41.5283203125, {
      wkid: 4326
    }),
    layerInfos: [layer1, layer2]
  };

Then you use your WMS Service URL and your options to add the view of your WMS endpoint to ArcGIS JS API:

      var wmsLayer = new WMSLayer('https://sampleserver1.arcgisonline.com/ArcGIS/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/WMSServer', {
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[GIS] Updating hosted feature layers on AGOL using the ArcGIS Python API

After a few weeks getting up to speed on the ArcGIS Python API, I have come up with work flow that works quite well. My original understanding of scripting using JSON dictionaries was a bit off as well as the structure of FeatureLayerCollection, FeatureLayer, FeaturesSet, and Feature objects from the new API. My process thus far involves manually publishing layers I need in the AGOL portal and then updating them through a process of truncation and then adding all of the updated local features to the hosted layers. Here is a simplified process that gives python access to the content of an AGOL portal, allows for truncating the layers, and adding features back to the layer from a local source.

import arcpy
import arcgis
from arcgis.gis import GIS

def TruncateWebLayer(gis=None, target=None):
    try:
        lyr = arcgis.features.FeatureLayer(target, gis)
        lyr.manager.truncate()
        print ("Successfully truncated layer: " + str(target))
    except:
        print("Failed truncating: " + str(target))
        sys.exit()

#create connection to AGOL portal GIS
mygis = arcgis.gis.GIS(r"https://aportal.maps.arcgis.com", "someUser", "somePassword")

#the URL of a single feature layer within a collection in an AGOL portal
publishedWebLayer = r"https://services6.arcgis.com/XXXXXXXXXXXX/arcgis/rest/services/XXXX/FeatureServer/0"

#a feature class on the local system with the same schema as the portal layer
updateFeatures = r"G:\DataData\Data.gdb\Data"

#remove all features from the already published feature layer
TruncateWebLayer(mygis, publishedWebLayer)

#reference the empty layer as FeatureLayer object from the ArcGIS Python API
fl = arcgis.features.FeatureLayer(publishedWebLayer, mygis)

#create a JSON object from the local features
jSON = arcpy.FeaturesToJSON_conversion(updateFeatures, localJSON)

#create a FeatureSet object from the JSON
fs = arcgis.features.FeatureSet.from_json(open(localJSON).read())

#add/append the local features to the hosted feature layer.
fl.edit_features(adds = fs)

This is a simplified example of how this can be achieved. A few things to note. I have not been able to get this process to work on more complicated geometries like curve rings, rings, etc. For polygons and lines I typically add an arcpy.Generalize_edit() before creating the JSON. This converts the curves into approximated line segments.

Best Answer

Related Solutions

[GIS] Adding WMS layer (basemap) to ArcGIS Javascript API

[GIS] Updating hosted feature layers on AGOL using the ArcGIS Python API

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