topic Exclude some data in a classBreaksDefinition, but still symbolize those records in ArcGIS JavaScript Maps SDK Questions

Exclude some data in a classBreaksDefinition, but still symbolize those records

TracySchloss — Thu, 03 Jul 2014 17:44:25 GMT

In Desktop, when symbolizing by a numeric value, not only can you specify classification method, interval, field etc, there's also a place to exclude some records. I routinely have data with a value of -999 to indicate 'no data'. In desktop, I can exclude those records from the classification calculation and still have a symbol on them that I can show on the map and legend.

I don't see that I can do the same thing with the objects available for classbreaksdefinition and generateRendererTask. If I exclude my 'no data', using a where clause, my classification calculates just fine, but they are completely eliminated from the display. That isn't what I want to see. I can't have those -999 in the calculations, that just gives weird breaks, but I still show them with some 'no data' symbol, not have them completely gone.

Am I missing something? It seems like I should be able to do this. I could probably make a second set of function just to display these no data records, but that sounds rather messy.

Re: Exclude some data in a classBreaksDefinition, but still symbolize those records

TracySchloss — Thu, 03 Jul 2014 18:25:04 GMT

The answer to this was as clear as mud, I just happened to try this and it worked.

When you specify your classDefinition, there's a place there to set your defaultSymbol. I had one defined based on the example https://developers.arcgis.com/javascript/jssamples/renderer_dynamic_layer_change_attribute.html

When you execute the generateRendererTask, the resultant renderer doesn't have a default symbol assigned to it anymore. I don't know if this in intentional or something that is broken in the task.

Before I applied this symbology to my layer, I manually went in and set the default symbol again on the renderer.

  function applyRenderer(renderer) {       var optionsArray = [];     renderer.defaultSymbol = defaultSymbol;     var drawingOptions = new LayerDrawingOptions();     drawingOptions.renderer = renderer;      optionsArray[0] = drawingOptions;     myLayer.setLayerDrawingOptions(optionsArray);    }

Now my excluded values of -999 are symbolized with that default and not just blank.