You want a dictionary keyword.
You can use them to edit the current feature, another feature in the same table, or one or more features in a different table or tables entirely.
Crucially, when setting up the rule, don't set it on any field for the output.
Here's an example of a rule that buffers a line automatically, updating any buffer that already exists as well as doing a field calculation on the feature to transform the measurement from feet to meters and miles.
//Reference: https://pro.arcgis.com/en/pro-app/latest/help/data/geodatabases/overview/attribute-rule-dictionary-keywords.htm
var rels = FeatureSetByRelationshipName($feature, "rowlines_rowbuffs", ["GlobalID"])
// Get list of buffers to be updated
var ups = []
var miles = $feature.Buffer_size_ft/5280
var meters = $feature.Buffer_size_ft *.3048
for (var rel in rels){
Push(ups, rel["globalID"])
}
// Return if the buffer field is empty
if (isEmpty($feature.Buffer_size_ft)){
return
}
// Buffer line by buffer field.
var geo = Geometry($feature)
geo = Buffer(geo, $feature.Buffer_size_ft, "feet")
// This part is tricky
// Construct pieces of your return dictionary
// Assume that it will be adding, like the other three attribute rules before this.
var edit = [{"attributes": {"Serial_Num": $feature.Serial_Num,
"Buffer_size_ft": $feature.Buffer_size_ft,
"relUUID": $feature.GlobalID
},
"geometry": geo
}]
var edittype = "adds"
// However, if there's already a buffer, change the dictionary
// to be updates and specify which record you want.
if (Count(ups)>0){
edit = [{"globalID" : ups[0], // In this case, we only want one buffer per line,
// so there should only be one in the list.
"attributes": {"Serial_Num": $feature.Serial_Num,
"Buffer_size_ft": $feature.Buffer_size_ft,
"relUUID": $feature.GlobalID
},
"geometry": geo
}]
edittype = "updates"
}
// Create the return dictionary with instructions to populate two different fields
// then add in the editing instructions from above.
var retDict = {
"result": {"attributes": {"Buffer_meter": meters,
"Buffer_miles": miles,}
},
"edit": [{"className": "rowbuffs"}]}
// I have to do it this way because if you just add in
// edittype:edit, it thinks the key is "edittype"
retDict["edit"][0][edittype] = edit
console(retDict)
/*
retDict = {"result": {"attributes": {"Buffer_meter": meters,
"Buffer_miles": miles,}
},
"edit": [{"className": "rowbuffs",
"updates": [{"globalID" : ups[0],
"attributes": {
"Serial_Num": $feature.Serial_Num,
"Buffer_size_ft": $feature.Buffer_size_ft,
"relUUID": $feature.GlobalID
},
"geometry": geo
}]
}]
}
*/
return retDict
Here's a file GDB (>=3.5) where this rule was used, as well as several rules that were earlier versions of this rule. The rules are mostly in order but reordering them is really hard so I kind of gave up.
It should be
- GenerateID (was just testing this rule out, you can ignore it)
- This is the only reason this geodatabase needs to be in 3.5, because the rule was introduced in this version. Everything else can be at Version>=2.7
- Calculate meters solo
- Calculate miles solo
- Meters and miles together
- Buffers no limits (make a new buffer each time the geometry changes)
- buffers delete (delete and replace the buffer when the geometry changes)
- buffers add and update (add or update buffer when geometry changes)
- Buffers add and update, calc different units (see above)
