ensure that OBJECTID (or similar) field need not be included in the 'fields' constructor option

[jgravois]

it'd be nice for users if they weren't required to specify an OBJECTID (or other field required for indexing) when they want to define "fields" in the FeatureLayer object constructor.

var myFeatureLayer = new L.esri.Layers.FeatureLayer(url, {fields: ["OBJECTID", "COOLFIELD"]}).addTo(map);

please assign this issue to me. i can look into how exactly we might refactor to make this change. at a minimum the existing requirement needs to be documented more clearly.

reference: SE

[jgravois]

first draft of fix can be found here

[patrickarlt]

Unfortunately this might not be the most efficient way to accomplish this. Here is how the code will flow now.

1. Instantiate L.esri.FeatureLayer with ['Name', 'Date']
2. Kickoff metadata request since we dont have an ID field
3. Add layer to map
4. start requests for all features in the current view with ['Name', 'Date']
5. at this point we have at least 5 requests (1 for metadata, 4 for features) when the metadata comes back it will force a refresh which will kickoff more requests. The only way to really solve this is to wait for the metadata request to finish before requesting features which means waiting for a round trip.

This approach would probably still produce an errors and issues since the features in the initial requests (before we know the ID field) will still be processed.

Another approach would be to simply check all the fields and see if they contain one of FID, OBJECTID or ObjectId ect...

Since 99% of services will have one of these common identifiers we could console.warn and push a message to developers instead which isn't ideal but is the only way to accomplish this without waiting for the metadata.

[jgravois]

that makes sense. how about something like this then?

[patrickarlt]

Yeah this makes more sense. you will also need to check for console and console.warn since they will be undefined in IE until you open the dev tools.

So the final check should look like if (oidCheck === false && console && console.warn){.

Would also be good to tweak the warning message to say something about including the field that contains the unique is of the features in the fields option.

[jgravois]

resolved by #371