topic Re: How do you use ArcGIS API for python to specify a layer based on title in ArcGIS Online Questions

How do you use ArcGIS API for python to specify a layer based on title

Damian — Fri, 19 Mar 2021 11:14:15 GMT

Dear ESRI community,

How do you use ArcGIS API for python to specify a layer in a web map based on the layers title? All of the samples I've seen just use the layer at index 0. I can't find any samples that search for a particular layer. For example:

my_webmap = gis.content.search(query="title:Trees",item_type="Web Map") my_item = my_content[0] wm = WebMap(my_item) Taxon_layer = wm.layers[0] #I want to select the layer where "Title" = "Taxon" Taxon_layer =============================================== Out: { "id": "Markup_X_3074", "layerType": "ArcGISFeatureLayer", "url": "https://services5.arcgis.com/wkEdAXzuNvKdAtLV/arcgis/rest/services/Markup_X/FeatureServer/0", "visibility": true, "opacity": 1, "title": "Taxon", "itemId": "b022f56ae0c347019ca2c9aae60c450c" }

Ultimately, I want to iterate through several web maps and modify a particular layer in each web map . The title is always the same but the index number will change each time. I know how to iterate, but I don't know how to select a layer based on title.

Any assistance greatly appreciated

Regards, Damian

Re: How do you use ArcGIS API for python to specify a layer based on title

jcarlson — Fri, 19 Mar 2021 12:17:50 GMT

There is a method get_layer() on the WebMap class, according to the API docs. Testing it, however, I can't get it to return anything.

There is also the layers property, which returns all the layers in a map as a dict. Iterating over that isn't too hard.

web_map = arcgis.mapping.WebMap(gis.content.get('webmap-itemID')) for l in web_map.layers: if l.title == 'Layer title you want': # do your layer edits here

Re: How do you use ArcGIS API for python to specify a layer based on title

Damian — Sun, 21 Mar 2021 23:27:18 GMT

Great, thank you Josh, that did the trick. I wonder if I could impose on you for one more question please (if you know the answer).?

Not only am I trying to specify a particular layer within a webmap (achieved above), I am also trying to specify a particular field within that layer. Example below:

my_webmap = gis.content.search(query="title:Trees",item_type="Web Map") my_item = my_webmap[0] my_itemID = my_item.id wm = WebMap(gis.content.get(my_itemID)) # Thank you Josh... for l in wm.layers: if l.title=="Gum Trees": l.popupInfo.fieldInfos[0].visible = True #I want to turn on the visibility for a field called "Species", #not just the first field in my layer.

So I want to run the command "l.popupInfo.fieldInfos[0].visible = True", for a field called "Species", not the first field at index '0' in my layer. As before, I want to iterate several layers and the index number may vary each time.

Regards, Damian

Re: How do you use ArcGIS API for python to specify a layer based on title

AdamGaudet — Tue, 09 Apr 2024 17:32:17 GMT

Thanks all for posting here. I spent a couple of days trying to do this exact same thing and was pulling my hair out. But now all issues are resolved. *Zen*

Re: How do you use ArcGIS API for python to specify a layer based on title

AdamGaudet — Tue, 09 Apr 2024 18:06:42 GMT

It's a few years after the fact, but did you ever solve for this issue? I might need to do something similar for another operation.