Thanks for the great repro case, @ShiminCai.
I'll share what we discussed via DM here in case others might find the explanation helpful.
You have this code in your repro app, which is creating a feature, adding it to the AGSGeodatabaseTable, then updating it:
@objc func sketchEditorGeometryDidChange() {
if sketchEditor.isSketchValid == true {
let newFeature = createNewFeature(geometry: sketchEditor.geometry!, featureLayer: featureLayer, featureTemplate: featureTemplate)
addFeature(newFeature: newFeature, featureLayer: featureLayer)
sketchEditor.stop()
updateFeature(feature: newFeature!)
}
}
func addFeature(newFeature: AGSFeature?, featureLayer: AGSFeatureLayer) {
if let featureTable = featureLayer.featureTable, featureTable is AGSGeodatabaseFeatureTable {
let geodatabaseFeatureTable = featureTable as! AGSGeodatabaseFeatureTable
geodatabaseFeatureTable.add(newFeature!, completion: { error in
if let error = error {
print("Error while adding feature: \(error.localizedDescription)")
return
}
})
}
}
func updateFeature(feature: AGSFeature) {
feature.attributes["SequenceNumber"] = sequenceNumber
featureLayer.featureTable!.update(feature, completion: { error in
if error != nil {
print(error!.localizedDescription)
//Geodatabase item not found.
} else {
self.sequenceNumber += 1
}
})
}
However, AGSGeodatabaseTable.add() is an asynchronous function, but you are not waiting for it to complete before you call AGSGeodatabaseTable.update(). So in other words, update() is being called to update an on-disk feature that isn't yet committed in the underlying .geodatabase file.
Changing your code to this fixes the issue:
@objc func sketchEditorGeometryDidChange() {
if sketchEditor.isSketchValid == true {
let newFeature = createNewFeature(geometry: sketchEditor.geometry!, featureLayer: featureLayer, featureTemplate: featureTemplate)
addFeature(newFeature: newFeature, featureLayer: featureLayer) { error in
if let error = error {
print("Error \(error.localizedDescription)")
return
}
self.updateFeature(feature: newFeature!)
}
sketchEditor.stop()
}
}
func addFeature(newFeature: AGSFeature?, featureLayer: AGSFeatureLayer, completion: @escaping (Error?) -> Void) {
if let featureTable = featureLayer.featureTable, featureTable is AGSGeodatabaseFeatureTable {
let geodatabaseFeatureTable = featureTable as! AGSGeodatabaseFeatureTable
geodatabaseFeatureTable.add(newFeature!, completion: { error in
if let error = error {
print("Error while adding feature: \(error.localizedDescription)")
completion(error)
return
}
completion(nil)
})
}
}
This code calls update() from the completion handler on add(), ensuring that add() has actually finished its work first.
In general, if a method has a completion block, it's safe to assume that until that completion block is called, the method won't have finished its work. Sometimes that's OK (for example, when setting a viewpoint on a map view) but other times it's critical to wait, as in this case.
Hope this helps!
