How do I change whether a field is editable in a hosted feature layer?

[JoshWhite]

I recently moved from SDE to Hosted Feature Layers in ArcGIS Online.  I have a field in one of my layers that is not editable.  I'm not sure how this happened.  It is nullable but I can't delete the content because on ArcGIS Online it says the field is not editable.  Any idea how to change this?  I would just reload the SDE layer but I have done a ton of edits and didn't realize this was an issue until now.  

[CraigRussell]

Hi Josh

You should be able to modify this field setting by updating the layer definition from the REST Administrator Directory.  There are some instructions/examples for updating definitions here - Update Definition (Feature Layer)—ArcGIS REST API | ArcGIS for Developers 

You can get to the administrator directory by navigating to the service URL and change it as follows:

FROM

https://services.myserver.com/OrgID/ArcGIS/rest/services/example/FeatureServer/0

TO

https://services.myserver.com/OrgID/ArcGIS/rest/admin/services/example/FeatureServer/0 

Update Definition appears at the bottom of the page under supported operations:

When using this, only include the content that you want to change - i.e. to update the editable setting on a field, copy out and update only the JSON for that field.  E.g.

If you haven't worked with definitions like this before then I'd suggest that you try this against a test/copy of the feature layer first until you're comfortable with the process.

Hope this helps!

Craig