Overview

This is supported from 10.1 onwards.

This document discusses the JSON classification definition objects. The classification definition optionally allows specifying symbology that would return a complete renderer object. It also includes an optional colorRamp object that is used to assign an unique color to each symbol.

The following classification definitions are discussed here:

• Class Breaks
• Unique Value

Class Breaks

Use class breaks classification scheme to group values in to classes.

Note about optional parameters:

• normalizationType and normalizationField - use these properties to normalize class breaks.
• baseSymbol and colorRamp - use these properties to include a symbol with varying color for each class.
  If only the baseSymbol is defined, then a default color ramp is used to assign a color for each class.
  If only the colorRamp is defined, then a default symbol would be created based on geometryType of the feature class and the colorRamp would used to assign color to the symbol for each class.
  If baseSymbol and colorRamp are missing then map server would assume default values for these properties and return the results with an appropriate symbol and color.
• When classificationMethod is "esriClassifyStandardDeviation" use standardDeviationInterval to specify the interval size. breakCount is ignored in this case.

JSON Syntax

{
  "type": "classBreaksDef",
  "classificationField": "<field name>",
  "classificationMethod": "<esriClassifyNaturalBreaks | esriClassifyEqualInterval | esriClassifyQuantile | 
				esriClassifyStandardDeviation | esriClassifyGeometricalInterval>",
  "breakCount": <count>,
  "standardDeviationInterval": < 1 | 0.5 | 0.33 | 0.25 >, //use when classificationMethod is esriClassifyStandardDeviation.
  
  //optional. use to normalize class breaks
  "normalizationType": "<esriNormalizeByField | esriNormalizeByLog | esriNormalizeByPercentOfTotal>",
  "normalizationField": "<field name>", //use when normalizationType is esriNormalizeByField
  
  //optional. use to define symbol for classes
  "baseSymbol": <symbol>,
  "colorRamp": <colorRamp>
}

JSON Example

{
  "type": "classBreaksDef",
  "classificationField": "POP2010",
  "classificationMethod": "esriClassifyNaturalBreaks",
  "breakCount": 5,
  "normalizationType": "esriNormalizeByField",
  "normalizationField": "Area"
}

Unique Value

Use unique value classification scheme to group values based on a unique combination of one or more (up to 3) fields.

Note about optional parameters:

• baseSymbol and colorRamp - use these properties to include a symbol with varying color for each class.
  If only the baseSymbol is defined, then a default color ramp is used to assign a color for each class.
  If only the colorRamp is defined, then a default symbol would be created based on geometryType of the feature class and the colorRamp would used to assign color to the symbol for each class.
  If baseSymbol and colorRamp are missing then map server would assume default values for these properties and return the results with an appropriate symbol and color.

JSON Syntax

{
  "type": "uniqueValueDef",
  "uniqueValueFields": ["<field name 1 >","<field name 2>","<field name 3>"],
  "fieldDelimiter": "field_delimiter_character",
  
  //optional. use to define symbol for unqiue values
  "baseSymbol": <symbol>,
  "colorRamp": <colorRamp>
}

JSON Example

//uniqueValue classification definition with symbology
{
  "type": "uniqueValueDef",
  "uniqueValueFields": ["Type", "AdminClass"],
  "fieldDelimiter": ",",
  "baseSymbol":
  {
    "type": "esriSLS",
    "style": "esriSLSSolid",
    "width": 2
  }
  "colorRamp":
  {
    "type": "algorithmic",
    "fromColor": [115,76,0,255],
    "toColor": [255,25,86,255],
    "algorithm": "esriHSVAlgorithm"
  }
}