Identify (Operation)

URL	`http://<mapservice-url>/identify`
Parent Resource	Map Service

Description

The identify operation is performed on a map service resource. The result of this operation is an identify results resource. Each identified result includes its name, layer ID, layer name, geometry and geometry type, and other attributes of that result as name-value pairs.

You can provide arguments to the identify operation as query parameters defined in the parameters table below.

Parameters

Parameter	Details
f	Description: The response format. The default response format is html. Values: html \| json
geometry	Required Description: The geometry to identify on. The type of the geometry is specified by the `geometryType` parameter. The structure of the geometries is same as the structure of the JSON geometry objects returned by the ArcGIS REST API. In addition to the JSON structures, for points and envelopes, you can specify the geometries with a simpler comma-separated syntax. Syntax: JSON structures: `geometryType=<geometryType>&geometry={geometry}` Point simple syntax: `geometryType=esriGeometryPoint&geometry=<x>,<y>` Envelope simple syntax: `geometryType=esriGeometryEnvelope&geometry=<xmin>,<ymin>,<xmax>,<ymax>` Examples: `geometryType=esriGeometryPoint&geometry={x: -104, y: 35.6}` `geometryType=esriGeometryPoint&geometry=-104,35.6` `geometryType=esriGeometryEnvelope&geometry=-104,35.6,-94.32,41` The coordinates must always use a period as the decimal separater even in countries where a comma is traditionally used.
geometryType	Description: The type of geometry specified by the `geometry` parameter. The geometry type could be a point, a line, a polygon or an envelope. The default geometry type is a point (`esriGeometryPoint`). Values: `esriGeometryPoint \| esriGeometryMultipoint \| esriGeometryPolyline \| esriGeometryPolygon \| esriGeometryEnvelope`
sr	Description: The well-known ID of the spatial reference of the input and output geometries as well as the `mapExtent`. If `sr` is not specified, the `geometry` and the `mapExtent` are assumed to be in the spatial reference of the map, and the output geometries are also in the spatial reference of the map.
layers	Description: The layers to perform the identify operation on. There are three ways to specify which layers to identify on: top: Only the top-most layer at the specified location. visible: All visible layers at the specified location. all: All layers at the specified location. Example: layers=all Default: By default the identify operation identifies the top-most layer (i.e. layers=top) You can either specify the layer options as mentioned above by themselves or specify the layer option in conjunction with a list of layer IDs. When both the layer option as well as the layer IDs are specified, the server treats it as a boolean "AND" operator. For example, if the parameter is specified as: layers=visible:2,5 only layers with IDs 2 and 5, if visible, are identified. Syntax: [top \| visible \| all]:layerId1,layerId2 where `layerId1, layerId2` are the layer ids returned by the map service resource. Example: `layers=visible:2,5`
tolerance	Required Description: The distance in screen pixels from the specified `geometry` within which the identify should be performed. The value for the tolerance is an integer. Example: `tolerance=2`
mapExtent	Required Description: The extent or bounding box of the map currently being viewed. Unless the `sr` parameter has been specified, the `mapExtent` is assumed to be in the spatial reference of the map. The `mapExtent` and the `imageDisplay` parameters are used by the server to determine the layers visible in the current extent. They are also used to calculate the distance on the map to search based on the `tolerance` in screen pixels. Syntax: `<xmin>, <ymin>, <xmax>, <ymax>` Example: `mapExtent=-104,35.6,-94.32,41`
imageDisplay	Required Description: The screen image display parameters (width, height and DPI) of the map being currently viewed. The `mapExtent` and the `imageDisplay` parameters are used by the server to determine the layers visible in the current extent. They are also used to calculate the distance on the map to search based on the `tolerance` in screen pixels. Syntax: `<width>, <height>, <dpi>` Example: `imageDisplay=600,550,96`
returnGeometry	Description: If true, the resultset will include the geometries associated with each result. The default is true. Values: `true \|` `false`

Example Usage

Example 1: Identify that includes geometry using simple point syntax, tolerance, map extent, and image display. Default values for geometry type, spatial reference, layers, and returnGeometry are used. The response is in HTML format:

http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer/identify?geometryType=esriGeometryPoint&geometry=-120,40&tolerance=10&mapExtent=-119,38,-121,41&imageDisplay=400,300,96

Example 2: Identify that includes geometry using a JSON structure. The response is in JSON format:

http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer/identify?geometryType=esriGeometryPoint&geometry={x: -120, y:40}&tolerance=10&mapExtent=-119,38,-121,41&imageDisplay=400,300,96&f=json

Example 3: Identify that specifies a specific layer. In this example, only layer 2 is desired. Since this is not the top layer, the syntax layer=all:2 is used:

http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer/identify?geometryType=esriGeometryPoint&geometry={x: -120, y:40}&layers=all:2&tolerance=10&mapExtent=-119,38,-121,41&imageDisplay=400,300,96&returnGeometry=true

JSON Response Syntax

{
"results" : [
 {
 "layerId" : <layerId1>,
 "layerName" : "<layerName1>", 
 "value" : "<value1>", 
 "displayFieldName" : "<displayFieldName1>",
 "attributes" : {
  "<fieldName11>" : <fieldValue11>,
  "<fieldName12>" : <fieldValue12>
 },
 "geometryType" : "<geometryType1>",
 "geometry" : {<geometry1>}
 },
 {
 "layerId" : <layerId2>,
 "layerName" : "<layerName2>",
 "value" : "<value2>", 
 "displayFieldName" : "<displayFieldName1>",
 "attributes" : {
  "<fieldName21>" : <fieldValue21>,
  "<fieldName22>" : <fieldValue22>
 },
 "geometryType" : "<geometryType2>",
 "geometry" : {<geometry2>}
 }
]
}

JSON Response Example

{
"results" : [
 {
 "layerId" : 3,
 "layerName" : "Cities",
 "value" : "Joe City",
 "displayFieldName" : "City Name",
 "attributes" : {
  "City Name" : "Joe City",
  "CLASS" : "city",
  "ST" : "CA"
 },
 "geometryType" : "esriGeometryPoint",
 "geometry" : { "x" : -118.375, "y" : 34.086, "spatialReference" : {"wkid" : 4326} }
 },
 {
 "layerId" : 59,
 "layerName" : "Parcel",
 "value" : "Parcel 649",
 "displayFieldName" : "NAME",
 "attributes" : {
  "NAME" : "Parcel 649",
  "SUB_REGION" : "Pacific",
  "STATE_ABBR" : "CA"
 },
 "geometryType" : "esriGeometryPolygon",
 "geometry" : { "spatialReference" : {"wkid" : 4326}, "rings" : [[[-118.35,32.81],[-118.42.806],[-118.511,32.892],[-118.35,32.81]]]}
 }
]
}