Allow more symbology classes than features

[ChelseaRozek]

Please allow us to have complete control over setting the number of symbology classes in ArcGIS Online. I'm trying to make an election result map with only 4 precincts for this election. I'd like to maintain a consistent voter turnout symbology, but I can't set all the classes I want because there aren't enough features. The documentation says that this is as designed: "Depending on how much data you have in a layer, you can also choose the number of classes—1 through 10. The more data you have, the more classes you can have." ESRI support mentions that equal interval allows more class breaks than features, but I would like it available for all, particularly manual breaks.

[AndrewBryson1]

Chelsea,

Do you have any experience using the ArcGIS Assistant to edit the JSON of a web map or web feature layer? I recommend it to people all the time, as the level of control it gives you is really unparalleled; and while I haven't ever used it to solve this particular problem, I'd be very surprised if it can't do the exact thing you're asking about.

Below is some sample JSON I had on hand. It's from a webmap I was working on recently. This is the section that specifies the graduated color symbology for a layer of census tracts, based on a tract's Score_State attribute:

"layerType": "ArcGISFeatureLayer",
"layerDefinition": {

			...

				"visualVariables": [
					{
						"maxSliderValue": 21,
						"minSliderValue": 0,
						"theme": "above-and-below",
						"type": "colorInfo"
					}
				]
			},
			"type": "classBreaks",
			"visualVariables": [
				{
					"type": "colorInfo",
					"field": "Score_State",
					"stops": [
						{
							"color": [
								117,
								113,
								114,
								255
							],
							"value": 6
						},
						{
							"color": [
								188,
								184,
								180,
								255
							],
							"value": 10
						},
						{
							"color": [
								218,
								230,
								213,
								255
							],
							"value": 13
						},
						{
							"color": [
								158,
								187,
								81,
								255
							],
							"value": 17
						},
						{
							"color": [
								93,
								122,
								6,
								255
							],
							"value": 20
						}
					]
				}

Using the Assistant, I think you should be able to set up your symbology the way you want it by either of two routes. You could either use a text editor to type the exact values you want into the "stops" array (lines 20 - 66 above); or you could work in the Map Viewer to create the symbology you want in another feature layer (one with a greater number of features) and then copy and paste the JSON from that layer into your 4-precinct layer.

I hope this workaround helps!

[ChelseaRozek]

I ran into this same issue today. This time I only have 2 precincts so I can't set manual classes in ArcGIS Online. For any data set with live values coming in that you aren't certain what they'll be, it would be very helpful to be able to make custom classes. For now, I think I'll use equal interval so I can have a different color for each 10%, but that's not what the customer wants to see. That's too many colors. They want to be able to see small nuances for around only 0-30%, so they really need custom class sizes.

Hi @AndrewBryson1 , sorry I missed your reply. I do have experience with ArcGIS Assistant, but that's beyond the capabilities of the average user so my idea is hoping this functionality can be built into the map viewer.