ArcGIS REST API

Legend (Map Service)

  • URL:http:// <mapservice-url>/legend
  • Required Capability:Map
  • Version Introduced:10.0

Description

The legend resource represents a map service's legend. It returns the legend information for all layers in the service. Each layer's legend information includes the symbol images and labels for each symbol. Each symbol is an image of size 20 x 20 pixels at 96 DPI. Additional information for each layer such as the layer ID, name, and min and max scales are also included.

The legend symbols include the base64 encoded imageData as well as a url that could be used to retrieve the image from the server.

Note:

This is a relative URL. It can be dereferenced by accessing the map layer image resource.

New in 10.6.1

  • Supports the following new parameters:
    • dpi to return legend patches at any resolution.
    • size to return line and polygon legend patches at a specific size.

New in 10.1 sp1

  • Legend response now includes height and width for symbols.

New in 10.1

  • Legend response contains a values json array for layers that are symbolized using either class breaks or unique value renderer.
    • In case of class breaks renderer, values contains the class maximum value.
    • In case of unique value renderer, values contains the list of ungrouped unique values.
  • Support for dynamicLayers was added.

Request Parameters

ParameterDetails
f

Description: The response format. The default response format is html.

Values: html | json

dynamicLayers

//This option was added at 10.1.

Description: Dynamic layers definition. This parameter is required only for generating a legend for dynamic layers.

Note:

supportsDynamicLayers on the map service resource should be true to use dynamicLayers property when requesting a legend.

Syntax:

[dynamicLayer1,dynamicLayer2,...,dynamicLayerN ]

dpi

Description: The device resolution of the exported image (dots per inch). If the dpi is not specified, an image with a default DPI of 96 will be returned for each legend patches.

Example: dpi=200

size

Description: The size width * height of the exported image in device independent units i.e. points (1" = 72 points). If the size is not specified, an image with a default size of 15 x 15 point will be exported.

Note:

size has no effects on point/marker legend patches since size point/marker legend patches depend on the actual marker size.

Syntax: <width>, <height>

Example: size=30, 20

Example Usage

Example 1:

http://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/legend?f=pjson

Example 2:

http://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/legend?dynamicLayers=[{"id":101,"source":{"type":"mapLayer","mapLayerId":3},"drawingInfo":{"renderer":{"type":"classBreaks","field":"pop2007","normalizationType":"esriNormalizeByPercentOfTotal","normalizationTotal":306348230,"minValue":0.17077754945736098,"classBreakInfos":[{"classMaxValue":1.7498315560693791,"label":"0.969259% - 1.749832%","description":"","symbol":{"type":"esriSMS","style":"esriSMSSquare","size":10.5,"angle":23,"xoffset":-10,"yoffset":0,"color":[0,255,255,255]}},{"classMaxValue":12.235568653358957,"label":"2.902453% - 12.235569%","description":"","symbol":{"type":"esriSMS","style":"esriSMSSquare","size":10.5,"angle":23,"xoffset":-10,"yoffset":0,"color":[0,0,255,255]}}]}}}]&f=html

JSON Response Syntax

{
  "layers": [
    {
      "layerId": <layerId1>,
      "layerName": "<layerName1>",
      "layerType" : "<layerType1>",
      "minScale": <minScale1>,
      "maxScale": <maxScale1>,
      "legend": [
        {
          "label": "<label11>",
          "url" : "<imageUrl11>", //Relative URL for static layers and full URL for dynamic layers. Access relative URL using http://<mapservice-url>/<layerId1>/images/<imageUrl11>
          "imageData" : "<base64EncodedImageData11>", 
          "contentType" : "<contentType11>",
          "height": <height>, //new at 10.1 SP1;
          "width": <width>, //new at 10.1 SP1;
          "values": [<maximum value1>] //In case of classBreaks renderer values will contain classMaxValue
        },
        {
          "label": "<label12>",
          "url" : "<imageUrl12>",
          "imageData" : "<base64EncodedImageData12>", 
          "contentType" : "<contentType12>",
          "height": <height>,
          "width": <width>,
          "values": [<maximum value2>]
        }
      ]
    },
    {
      "layerId": <layerId2>,
      "layerName": "<layerName2>",
      "layerType" : "<layerType2>",
      "minScale": <minScale2>,
      "maxScale": <maxScale2>,
      "legend": [
        {
          "label": "<label21>",
          "url" : "<imageUrl21>", //Relative URL for static layers and full URL for dynamic layers. Access relative URL using http://<mapservice-url>/<layerId2>/images/<imageUrl21>
          "imageData" : "<base64EncodedImageData21>", 
          "contentType" : "<contentType21>",
          "height": <height>,
          "width": <width>,
          "values": ["uniqueValue1"] //In case of uniqueValue renderer values will contain ungrouped unique values.
        },
        {
          "label": "<label22>",
          "url" : "<imageUrl22>",
          "imageData" : "<base64EncodedImageData22>", 
          "contentType" : "<contentType22>",
          "height": <height>,
          "width": <width>,
          "values": ["uniqueValue2", "uniqueValue3"]
        }
      ]
    }
  ]
}

JSON Response Example

{
 "layers": [
  {
   "layerId": 0,
   "layerName": "Census Block Points",
   "layerType": "Feature Layer",
   "minScale": 99999,
   "maxScale": 0,
   "legend": [
    {
     "label": "0 - 61",
     "url": "16c1750c363249f0a97da4bfd6d99a49",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAFNJREFUOI1jYaAyYBk1cNRAOPiPxGak1MD/JZsR5vX4Mv7HZyghA1EMY2BgYCjZ/B+voUM/Uhh7fBnRw5CBgYIwhBuKzKfEhUQZQo6BRINRAykHADL/FCzY81v0AAAAAElFTkSuQmCC",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      61
     ]
    },
    {
     "label": "62 - 264",
     "url": "96b1e45aea277d25d6759101c5a568f2",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAGRJREFUOI3t0cEJwDAMA0AZsp63yRjeJgO6v35iOU0oJZToKfA9rIKXUw74CehBJ6ug19Z7puIMzcAQA4DanKIMpNgI/cfKe4JiKukwpgJMrJyiDBuBNxr17ODJD+nxKjiV/cELXCYgLEwEnd4AAAAASUVORK5CYII=",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      264
     ]
    },
    {
     "label": "265 - 759",
     "url": "eec6c4375388bb67e0bd976a7476bbcf",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAIdJREFUOI3d1MEJwCAMBdAEXM9tOobbdMD0YorGH2ulIjRHTR8fEhvo4wo7QAFnPAMKEdFxtl6KrIcNjEAX0tI7BMOEPcz2pViHtKCMYgYVTbl0yq/TaZUpt+zhj0FOkacGk3dx/doQTaQs0yHwbhpB7bPzQM7Nvb9N1fsEQhjdoRoZivsxqgsOTDUsDDFUxQAAAABJRU5ErkJggg==",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      759
     ]
    },
    {
     "label": "760 - 1900",
     "url": "2b73fd7416e13da8cdec1865ca48ca1f",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABUAAAAVCAYAAACpF6WWAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAIlJREFUOI3t1cENgCAMBdDfhPXYxjHYxgHxQglWWhXKwcReCy8/aQMBdmWjR1ojWNi262aKxM0L3kOzhXHxmYKfYIk+AiUu4RZ9DWowo8NgD9YGNVUBDim5OO2ypD/6EZRSJJe1SpGAlcsPOKTllC06BbegRIdgCfbQCgO3L389L3vaoKhcHPqjDhqnRC6j0pDtAAAAAElFTkSuQmCC",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      1900
     ]
    },
    {
     "label": "1901 - 9409",
     "url": "0f3caba8a8bff54af2f795d36fa00b64",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABoAAAAaCAYAAACpSkzOAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAKBJREFUSInt1sENgCAMBdDfhPXYxjHYxgHxVIOVFtCiF/61TV5+gISAjxIGdrMxIw8oA8C2606KxEMVtKAmwOEdC9Sg3AM0wAtWgx4hEpSYhF4jGjZy616lhNzacMpWnzdyb8PhVr+c0YIWBACgFGnKFU+RgD8eLDChFbeR0NRIyK1V2aYGuWAS0aATA/r+DAK4IRZ0LveAFtADVUFrx8oBsCBQQjt9MuwAAAAASUVORK5CYII=",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      9409
     ]
    }
   ]
  },
  {
   "layerId": 1,
   "layerName": "Census Block Group",
   "layerType": "Feature Layer",
   "minScale": 1000000,
   "maxScale": 0,
   "legend": [
    {
     "label": "",
     "url": "9f9da73612bae8cabdfccb9dc9ebb5ec",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAADpJREFUOI1jYaAyYKGZgU1NTf8pNayuro6RBV2AXMNgDqKdl0cNHDVw1MBRA3EaSEmZCCv6WNAFKAUAXT0NzOV1EscAAAAASUVORK5CYII=",
     "contentType": "image/png",
     "height": 20,
     "width": 20
    }
   ]
  },
  {
   "layerId": 2,
   "layerName": "Detailed Counties",
   "layerType": "Feature Layer",
   "minScale": 0,
   "maxScale": 0,
   "legend": [
    {
     "label": "",
     "url": "98fb6d62c20377d8d861e56ede28766f",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAADZJREFUOI1jYaAyYKGlgf+pYB4jugsZKTDsPwMDjb08auCogaMGjhqI00BKykRGdAMpKQvhAABd0QNSDPGCHwAAAABJRU5ErkJggg==",
     "contentType": "image/png",
     "height": 20,
     "width": 20
    }
   ]
  },
  {
   "layerId": 3,
   "layerName": "states",
   "layerType": "Feature Layer",
   "minScale": 0,
   "maxScale": 0,
   "legend": [
    {
     "label": "",
     "url": "bb835639802a7005b5d50553e8a13dce",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAADdJREFUOI1jYaAyYIHS/6lkHiMLYTWkAXQDGck0B+5Dmrtw1MBRA0cNHB4GUlwu0syF5JaDGAAABzUDUfxbIJcAAAAASUVORK5CYII=",
     "contentType": "image/png",
     "height": 20,
     "width": 20
    }
   ]
  }
 ]
}

JSON Response Example (for dynamic map layers)

{
 "layers": [
  {
   "layerId": 101,
   "layerName": "states",
   "layerType": "Feature Layer",
   "minScale": 0,
   "maxScale": 0,
   "legend": [
    {
     "label": "0.170778% - 0.441503%",
     "url": "http://sampleserver6.arcgisonline.com/arcgis/rest/directories/arcgisoutput/Census_MapServer/_ags_legend_be1f0e6f9480468a9d7e7b6f43f9dbe3.png",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAHZJREFUOI2108sOgCAMRNFpwv//cl0oCdTaB62zNZ5cAw40b6TfYDAAgEA1cELObNBCGKxV6mCwRtsOZiGlclSL5PKnLCcqb5BAXZX1wk+wUrl89o+F1T2VO9hwOD2Fr2sjH0Yrw//yAWSDWqWB+OAB5INJaO4CLn4gU6oOM3wAAAAASUVORK5CYII=",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      0.44150279569103434
     ]
    },
    {
     "label": "0.441504% - 0.969258%",
     "url": "http://sampleserver6.arcgisonline.com/arcgis/rest/directories/arcgisoutput/Census_MapServer/_ags_legend_b78cba0cf8ee4f2499b01018e7f43f09.png",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAHdJREFUOI2100sOgDAIRVFIunB2jgPbxCLyKfimxpNrWgc0b6TfYGIAAEDCGrggZzZoIUysVepgsEbbDmYhpXJUi+TypywnKm8QCbsq64WfYKXy8dk/FlY3K3ew4XB6Cl/XRj6MVob/5QPIBrVKA/HBA8gHk9DaBR97MNOpuBjQAAAAAElFTkSuQmCC",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      0.96925841549663927
     ]
    },
    {
     "label": "0.969259% - 1.749832%",
     "url": "http://sampleserver6.arcgisonline.com/arcgis/rest/directories/arcgisoutput/Census_MapServer/_ags_legend_63250b4a6f8d4c99aae77d4ca275501b.png",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAHZJREFUOI2108sOgCAMRNFpwv//cl0oCdTaB62zNZ5cAw40b6TfYGYAABHVwAk5s0ELYWatUgeDNdp2MAsplaNaJJc/ZTlReYNE1FVZL/wEK5XLZ/9YWN1TuYMNh9NT+Lo28mG0MvwvH0A2qFUaiA8eQD6YhOYuvaAwVEoxj/0AAAAASUVORK5CYII=",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      1.7498315560693791
     ]
    },
    {
     "label": "1.749833% - 2.902452%",
     "url": "http://sampleserver6.arcgisonline.com/arcgis/rest/directories/arcgisoutput/Census_MapServer/_ags_legend_28618eb5d5ed444c8159679a43cf0f7e.png",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAHZJREFUOI21k0sOwCAIBUvCwb05XVSTllI+PjobF8bJGJSPZrh8YohcKxEmXKIAX+hJhohVaQuTNRZPYVVkVDJapKlPWaMqZyFRVyVe+ClEKm/X/rEQZVaqd4gPp6fw9Wz0ZrYy/Zc3RL7QqnQksXBDFAuLosUJH/ow03WzBn8AAAAASUVORK5CYII=",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      2.9024522191624871
     ]
    },
    {
     "label": "2.902453% - 12.235569%",
     "url": "http://sampleserver6.arcgisonline.com/arcgis/rest/directories/arcgisoutput/Census_MapServer/_ags_legend_a3e7573e466c4249a41bc34d34de059e.png",
     "imageData": "iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAHRJREFUOI2100EOgCAMRFGb9P5XrgskhNJCy9TZuDC+fIPyUzzOPyLSrkQg2KH9DuAOEbEqHTBWY02BWWitZLRI7+KU9ebKDySqqiwodEGkcrz2n4XoWqUC8cMpKlw+G30zWhn+l/PQAbQqfSQA5qEAmIP6Xh59IFML5CgnAAAAAElFTkSuQmCC",
     "contentType": "image/png",
     "height": 20,
     "width": 20,
     "values": [
      12.235568653358957
     ]
    }
   ]
  }
 ]
}