topic Re: Where Clause - DynamicMapService in ArcGIS JavaScript Maps SDK Questions

Where Clause - DynamicMapService

BrandonIves — Tue, 01 Jul 2014 12:03:02 GMT

Hi,

Is it possible to set a where clause on a Dynamic Map Service Layer?

I would like to filter my display by a field that changes depending on user interactions or user privledges to see certain data.

I have used a feature service to do this but thought it would be nice for "read-only" users. I also wouldn't have to create a second feature service with update, add, delete unchecked for read only users.

Thanks

Re: Where Clause - DynamicMapService

TracySchloss — Sat, 11 Dec 2021 15:52:45 GMT

I have been working through the sample https://developers.arcgis.com/javascript/jssamples/renderer_dynamic_layer_change_attribute.html which allows the user to select a field from the specified service and generate a classification based on that field.

It is based on a ArcGISDynamicMapServiceLayer. In order to activate the 'dynamic layers' functionality you have

create a geodatabase or shape file workspace and author that as a geodata service

Check the box under Capabilities > Mapping in Properties to "Allow per request modification ..."

click "Manage" to browse the the geodata service you just made.

The geodata service is just a temporary workspace, near as I can tell. It doesn't have anything in it.

In my data, I have some values of -999 which indicates 'No data'. I didn't want these to be included when I generated my renderer, so I needed a where clause. In the sample, the function classBreaks is where the GenerateRendererParameters is defined. I added a where clause, shown in red, which takes the field the user selected and excludes the -999 data so it doesn't get used when I generate the renderer. I also needed to round my numbers, since some have too many decimals. It seems to be working just fine. I still need to figure out if you can symbolize this excluded data, with maybe a gray color or something.

        function classBreaks(c1, c2) {
          var classDef = new ClassBreaksDefinition();
          classDef.classificationField = registry.byId("fieldNames").get("value") || "CROP_2002_ACRES_TREATED";//this is a field in my data
          classDef.classificationMethod = "natural-breaks"; 
          classDef.breakCount = 5; // always five classes

          var colorRamp = new AlgorithmicColorRamp();
          colorRamp.fromColor = new Color.fromHex(c1);
          colorRamp.toColor = new Color.fromHex(c2);
          colorRamp.algorithm = "hsv"; // options are:  "cie-lab", "hsv", "lab-lch"
          
          classDef.baseSymbol = new SimpleFillSymbol("solid", null, null);
          classDef.colorRamp = colorRamp;

          var params = new GenerateRendererParameters();
          params.classificationDefinition = classDef;
          params.precision = 2;
          params.formatLabel = true;
          var clauseInput = classDef.classificationField;
          params.where= clauseInput + " > 0";
          var generateRenderer = new GenerateRendererTask(app.dataUrl);
          generateRenderer.execute(params, applyRenderer, errorHandler);
        }

I just happened to be working on this for the first time this AM, so I don't know much more than "I got it to work".

You must have ArcGIS Server version 10.1 or higher to use this.

Re: Where Clause - DynamicMapService

BrandonIves — Sat, 11 Dec 2021 15:52:48 GMT

Thanks for the response Schlot.

I have been working through the sample https://developers.arcgis.com/javascript/jssamples/renderer_dynamic_layer_change_attribute.html which allows the user to select a field from the specified service and generate a classification based on that field.

It is based on a ArcGISDynamicMapServiceLayer. In order to activate the 'dynamic layers' functionality you have

create a geodatabase or shape file workspace and author that as a geodata service

Check the box under Capabilities > Mapping in Properties to "Allow per request modification ..."

click "Manage" to browse the the geodata service you just made.

The geodata service is just a temporary workspace, near as I can tell. It doesn't have anything in it.

In my data, I have some values of -999 which indicates 'No data'. I didn't want these to be included when I generated my renderer, so I needed a where clause. In the sample, the function classBreaks is where the GenerateRendererParameters is defined. I added a where clause, shown in red, which takes the field the user selected and excludes the -999 data so it doesn't get used when I generate the renderer. I also needed to round my numbers, since some have too many decimals. It seems to be working just fine. I still need to figure out if you can symbolize this excluded data, with maybe a gray color or something.

Is this the only way that you know of to implement a where clause? This seems very involved considering a feature service is this simple:

 
FeatureLayer l = new FeatureLayer()
                {
                    ID = "MyFeatureLayer",
                    Url = "http://serverNameBlahBlah/WPFTestFeatureLayer/FeatureServer/0",
                    //Where = "1=1"
                    Where = "ASSIGNED_TO = 'GIS_USER'"

                    //,
                    //Renderer = "{StaticResource MySimplePointRenderer}"

                };

Re: Where Clause - DynamicMapService

ManishkumarPatel — Wed, 02 Jul 2014 06:15:18 GMT

Hi Brandon,

You can try to set the layerDefinitions for the dynamic map service layer you are trying to add to the map.

for eg:

var imageParameters = new ImageParameters();
imageParameters.layerIds = [0,1];
var layerDef = [];
layerDef[] = "upper(MAPNOTE_TYPE)='PUBLIC' and RECORD_STATUS='A'"; //where clause here
imageParameters.layerDefinitions = layerDef;
imageParameters.layerOption = esri.layers.ImageParameters.LAYER_OPTION_SHOW;
imageParameters.format = "jpeg"; //set the image type to PNG24, note default is PNG8.
var dynamicMapServiceLayer = new ArcGISDynamicMapServiceLayer(MapServiceLyrURL, {
                                "imageParameters": imageParameters,
                                "id": MapServiceLyrId,
                                "visible": true
                            });
map.addLayer(dynamicMapServiceLayer);

For further info refer to the below links:

Image Parameters
https://developers.arcgis.com/javascript/jsapi/imageparameters-amd.html

Layer Definitions:
https://developers.arcgis.com/javascript/jsapi/imageparameters-amd.html#layerdefinitions

Hope this helps.

Regards,
Manish

Re: Where Clause - DynamicMapService

BrandonIves — Wed, 02 Jul 2014 12:18:36 GMT

Thanks for the information.

Re: Where Clause - DynamicMapService

TracySchloss — Wed, 02 Jul 2014 15:42:36 GMT

Sorry I misread your question. I thought you were asking about dynamically generating symbology for a selected layer. My instructions were for that.

Re: Where Clause - DynamicMapService

BrandonIves — Wed, 02 Jul 2014 16:17:21 GMT

Sorry I misread your question. I thought you were asking about dynamically generating symbology for a selected layer. My instructions were for that.

No problem. Your answer led me to consider some other options for another application. Thanks!