Latest Contributions by Bud

AGOL: Advanced views (join views) are a hassle since they lock the schema of the underlying feature layers.  Once the layers are rolled into a map/app, it's too much of a hassle to drop the join, make changes to the underlying layers, re-join, and repair the map/app. This idea is to create advanced views without locking underlying feature layer schemas. ... View more

Databases like SQL Server and PostgreSQL (and Oracle) support SQL expression fields right in the table, called computed columns, generated columns, virtual columns, etc. This idea is to make use of such columns by adding an SQL expression field type, right in the AGOL table/hosted feature layer. For example, AGOL > hosted feature layer > Data tab > Fields view > a read-only field > properties > SQL expression:  'SEWER-' || asset_num_integer The other fields would remain editable in ArcGIS apps, which would be ideal. SQL expressions right in the db table would perform better than other expression mechanisms like arcade or even advanced REST API views.   A related, but different, ArcGIS Pro idea: Virtual Attributes (ad hoc) ... View more

What are the rules when setting default values for AGOL hosted feature layer fields? (using the Admin REST API) For example: Use SQL Server's SQL syntax/dialect. GIS Stack Exchange: What kind of database does ArcGIS Online use to store data? GUID and number fields support expressions, but text fields don't. Idea: Allow expressions in AGOL string field > default value Here's a useful error message I got when trying to use OBJECTID+1 as the default value for an integer field: "Valid expressions are constants, constant expressions, and (in some contexts) variables. Column names are not permitted." Link Are there any other known rules? Or any other useful error messages that could be noted here?   (To Esri staff: Could the rules be added to the AGOL docs?) ... View more

AGOL hosted feature layers; Experience Builder; editor widget When copying/pasting a feature from Layer1 to Layer2, how does ExB determine what fields to match/copy? I assume it's matching fields that have exactly the same name. Where does the list of fields to copy come from? Does the list of fields come from the AGOL hosted feature layer, the web map, the web map form configuration, the layer in Experience Builder, or the list of fields in the editor widget? True field names or field aliases? I assume true field names. If fields are excluded in the editor widget, do they not get copied/pasted? What are the rules when copying/pasting a feature into a different feature layer? ... View more

Expression fields (calculated columns) in advanced views seem to be limited to joined views. They don’t work with regular view layers.  For example, concatenate “SEWER-“ text with an integer field to produce prefixed ASSET_IDs like SEWER-0000001. Documentation: ArcGIS REST APIs > Add to Definition (Feature Service) Question: Create advanced AGOL view with expression field (no joins)? Could expression functionality be added to views that don’t have a joined table? ... View more

Summary: Admin REST API > view's sublayer > Add To Definition Added an expression field via JSON It ran without errors, but I don't see the new field in the view.   Detailed Steps: I've created a AGOL view called test_layer_view on a hosted feature layer: In the view, using the Admin REST API, I want to add a expression field as a test, calculating 1+1. I'm not using the view's top-level feature layer... ...Instead, I'm using the sublayer: (Let me know if I'm using the wrong item. Although I tested with the top-level feature layer view, and had the same issue with it.)   I got some sample JSON from the ArcGIS REST APIs > Add to Definition (Feature Service) documentation: (Those docs are pretty complicated and geared towards joins, so I'm not sure how to boil the sample JSON down to just a simple expression field without a join.) { "sourceLayerFields": [ { "name": "test_expression_field", "alias": "test_expression_field", "expression": "1+1", "type": "esriFieldTypeInteger" } ] } I hit the "Add To Layer Definition" button and it ran without errors: But when I refresh the view's Data > Fields tab (or the Table tab), the expression field is missing. Likewise, the expression field is missing from the sublayer's JSON definition. What am I doing wrong?   ... View more

AGOL hosted feature layer: For non-string fields like GUIDs and integers, we can set up default value expressions using the Admin REST API: (The user-defined field name is unique_id.) GUID:  "defaultValue" : "NEWID()" Inserts a GUID value like 7ec3018d-4a49-4a13-8e15-005846b25848 Integer: "defaultValue" : "IDENT_CURRENT('db_2xxxx.user_2xxxx.test_layer_TEST_LAYER')" Inserts a copy of the Object ID. But for string fields, everything we try to put into a string field just ends up writing the function name and parameters as a literal string, e.g. "CONCAT(v1, v2)". We are trying to insert a sequential integer ID with a text prefix, such as SEWER-0000001. There seems to be a limitation where the system has no way to differentiate a literal string from an expression/function. Could expression functionality be added for string default values? Related AGOL Question:  https://community.esri.com/t5/arcgis-online-questions/add-guid-field-to-existing-agol-survey123-feature/m-p/1699854/highlight/true#M68606   @MobiusSnake  We're aware that IDs can be generated/inserted at the app level. But there are cases where it'd be preferrable to do it at the AGOL hosted feature layer level, so the IDs are inserted globally, regardless of where the edit is happening. ... View more