How to show each points name as a label in the offline map?

[AlisherMirzoev]

Hello, I'm developing offline map for iOS using TPK package as a basemap and some local shape files for feature layers. Everything is working fine except labeling. I have a huge data more than thousand points in the map which is loading from table in shape file, I want to show each POI name as a text/label instead of dot or it could be placed next to dot in the map. I've tried to see documentation and I found only Label expression which is for online use only, but no luck for my case. Is there any other solution? I also tried clusters but it seems for symbols and online data only. May be I cannot getting there how to implement it in offline environment ? Thanks in advance.

[RyanOlson1]

You can add labels to shapefile data. We do not have a comprehensive api for creating the label definition through properties, however one can be created with json like so:

            let map = AGSMap(basemapType: .lightGrayCanvas, latitude: 0, longitude: 0, levelOfDetail: 0)
            
            let shp1 = AGSShapefileFeatureTable(fileURL: URL.TestDataURL("Shapefile/FromArcMap/CapitalsFromAM.shp"))
            let fl1 = AGSFeatureLayer(featureTable: shp1)
        
            map.operationalLayers.add(fl1)
            
            let jsonStr = """
                               {"labelPlacement":"esriServerPointLabelPlacementAboveRight","where":null,"labelExpression":"[CITY_NAME]","useCodedValues":true,"symbol":{"type":"esriTS","color":[255,0,0,255],"backgroundColor":null,"borderLineColor":null,"borderLineSize":null,"verticalAlignment":"bottom","horizontalAlignment":"center","rightToLeft":false,"angle":0,"xoffset":0,"yoffset":0,"kerning":true,"haloColor":[255,255,255,255],"haloSize":2,"font":{"family":"Arial","size":10,"style":"normal","weight":"normal","decoration":"none"}},"minScale":0,"maxScale":0}
                               """
            
            guard let jsonData = jsonStr.data(using: .utf8) else{
                return
            }
            
            let jsonObject = try JSONSerialization.jsonObject(with: jsonData, options: [])
            
            let labelDefinition = try AGSLabelDefinition.fromJSON(jsonObject)
            
            fl1.labelsEnabled = true
            fl1.labelDefinitions.add(labelDefinition)
            
            mapView.map = map‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

That code will give label the `CITY_NAME` field for each point in the shapefile. It will be a red (255,0,0,255) text symbol with a white halo.

[AlisherMirzoev]

Thank you very much, it's a great approach!

But I see Arabic fonts doesn't support at all, only English for now and I got error "Errors thrown from here are not handled" for "try". Then it worked fine when I put it inside do { } catch handler. 

[wuep]

Thanks for this Post. It just helped me. I had to use the constructor:

AGSShapefileFeatureTable(fileURL: mypath_to_shapefile_in_document_folder)

 and it was very helpful to have the information that the file path to the .shp File of the shape folder had to be provided.

In the current version of the API documentation about it unfortunatelly is missing this concrete helpful and important information!

Parameters

FileURL: to existing shapefile (including .shp file extension)

The following text should be added to this documentation:

The parameter for fileURL has to be the URL to the file with the extension ".shp".