GET_FEATURES

Used in

REQUEST  

Servers

Query  Feature  

Parent elements

REQUEST 

Syntax

<GET_FEATURES	Attribute Description Table
attributes="true | false" [true]      beginrecord="integer" [0]      checkesc="true | false" [false]      compact="true | false" [false]      envelope="true | false" [false]      featurelimit="integer" [all features]      geometry="true | false" [true]      globalenvelope="true | false" [false]      outputmode="binary | xml | newxml" [binary]      skipfeatures="true | false" [false] >      (r)<LAYER... />      (r)<QUERY... /> [Or]      (r)<SPATIALQUERY... /> [Or]      <ENVIRONMENT... />      <WORKSPACES... /> [Image Services only] </GET_FEATURES >
(r): Attribute or child element is required.

Description

Requests features as a compressed binary stream from the Feature Server or requests attribute data in ArcXML format from the Query Server.

Restrictions

• Request can only be used on one layer at a time.
• Queries on dynamic layers are valid only with Image Services.
• Either SPATIALQUERY or QUERY is required.
• WORKSPACES is a valid child element with Image Services only.
• Skipfeatures is valid only when outputmode is set to "xml" or "newxml".

Notes

• See FEATURES for response.
• A GET_FEATURES request to an Image Service gets routed to the Query Server. This routing information is contained in the URL sent to the ArcIMS site such as in the following example (all one line):
  http://myComputer.domain.com/servlet/com.esri.esrimap.Esrimap?ServiceName=myservice
          &CustomService=Query
          &Form=True&Encode=True
  
  
• In order to query dynamic layers in a GET_FEATURES request, MAP must include dynamicfeature in the map configuration file.
  <MAP dynamicfeature="true" />
• The attributes beginrecord and featurelimit are used together to limit the number of features returned. Featurelimit is used to set the number of features returned. Beginrecord is used to start the retrieval at a specified record. For example, if 25 features should be returned, featurelimit is set to "25". For the first retrieval, beginrecord starts at "0" (the default). For the second retrieval, beginrecord should start at "25". To determine whether more than 25 features were extracted, the attribute hasmore in the FEATURES response will be set to "true" (more records) or "false" (no more records).
• Outputmode defines whether the data is streamed to the client or sent to the client in ArcXML format. If outputmode is binary, then the request goes to the Feature Server and the response is a compressed binary stream. This is the default and is valid only for Feature Services. To return data in ArcXML format, outputmode can have one of two values: newxml or xml.
  
  If outputmode="xml", then all features are returned in a short ArcXML format using the FIELDS element. This format is not valid for use with the ArcXML DTD:
  <FIELDS CUST_ID="4" NAME="Customer" #SHAPE#="[Geometry]" #ID#="3" />
  
  If outputmode="newxml" then all fields are returned in a longer ArcXML format in the FIELD element. This format can be used with the ArcXML DTD:
  <FIELDS>
    <FIELD name="CUST_ID" value="4" />
    <FIELD name="NAME" value="Customer" />
    <FIELD name="#SHAPE#" value="[Geometry]" />
    <FIELD name="#ID#" value="3" />
  </FIELDS>
• Compact can be used to switch the geometry used in the output ArcXML to a shortened format. When compact is true, the response uses the COORDS element:
  <MULTIPOINT>
    <COORDS>-122.406680 37.747422;-123,500555 37.820000</COORDS>
  </MULTIPOINT>
  
  When compact is false, the response uses the POINT element:
  <MULTIPOINT>
    <POINT x=-122.406680 y=37.747422 />
    <POINT x=-123,500555 y=37.820000 />
  </MULTIPOINT>
  
  Setting compact to "true" means the geometry requires less bandwidth by the request or response. However, performance may be better when compact="false" when a large number of coordinate pairs are used, even though the requests and responses are longer.
• Two methods can be used to retrieve the number of selected features without returning FEATURE elements:
  • To get the total number of seclected features but not a global envelope, you can use GET_FEATURES skipfeatures="true". In the FEATURES response, only FEATURECOUNT is returned. You can include a global envelope by setting both GET_FEATURES skipfeatures and globalenvelope to "true".
  • To get the total number of selected features and a corresponding global envelope, you can use the following combination of attributes in GET_FEATURES:
    • attributes="false"
    • geometry="false"
    • envelope="false"
    • globalenvelope = "true"
    When attributes, geometry, and envelope are set to "false", only FEATURECOUNT is returned. If globalenvelope is set to "true", the global envelope is included using ENVELOPE. If globalenvelope is set to "false", no ENVELOPE is returned. If at least one attribute among attributes, geometry, and envelope is set to "true", FEATURE elements are returned.
• For more details on using GET_FEATURES and FEATURES, including additional examples, see Using GET_FEATURES and FEATURES.

Attribute Descriptions for GET_FEATURES

Attribute	Usage
attributes	Determines whether attribute data for selected features is returned in the response.
beginrecord	Index of first extracted record.
checkesc	Used to determine if the returned data should include escaped characters for ampersand, single quote, double quote, less than, and greater than. For example, if the value for SUB_REGION is "P&NW", then: If checkesc="false", in the response the value of SUB_REGION is "P&NW". If checkesc="true", the value of SUB_REGION is "P&NW".
compact	Switches geometry to compact form in the response. See Using GET_FEATURES and FEATURES for more details. Setting compact to "true" means the geometry requires less bandwidth by the request or response. However, performance may be better when compact="false", even though the requests and responses are longer.
envelope	Used to request the bounding envelope of each returned feature.
featurelimit	Maximum number of returned features.
geometry	Requests feature coordinates.
globalenvelope	When set to "true", the overall envelope for all the features returned is included in the response. Since the number of features returned depends on beginrecord and featurelimit, only the actual records extracted based on featurelimit are included in the overall envelope. Note that in order for the global envelope to be returned, subfields in the SPATIALQUERY must include either #SHAPE# or #ALL#.
outputmode	If outputmode is binary, data is compressed into a binary stream. If the value of "xml" is used, data is returned in ArcXML format. This format uses a shorthand format that is faster to parse in an HTML client. If "newxml" is used, the data is returned in a longer format. See Using GET_FEATURES and FEATURES for more details.
skipfeatures	When set to "true", only the number of features is returned without including any information on individual features. The number of features returned depends on beginrecord and featurelimit. To get the total number of features in a layer, a query can be specified with an empty where clause. Note that even when skipfeatures is set to "true", the query is executed and features are actually extracted before they are counted. This attribute is valid only when outputmode is "xml" or "newxml".

Back to top 

Examples for GET_FEATURES

Example 1: When a layer from the service is queried.

<?xml version="1.0" encoding="UTF-8"?> <ARCXML version="1.1"> <REQUEST>   <GET_FEATURES featurelimit="25" beginrecord="0" outputmode="xml" geometry="false" envelope="true" compact="true">     <LAYER id="4" />     <SPATIALQUERY subfields="#ALL#" where="NAME  =  'Los Angeles'" >     </SPATIALQUERY>   </GET_FEATURES> </REQUEST> </ARCXML>

Example 2: When a dynamic layer is queried.

<?xml version="1.0" encoding="UTF-8" ?> <ARCXML version="1.1">   <REQUEST>     <GET_FEATURES featurelimit="25" beginrecord="0" outputmode="newxml" geometry="false" envelope="true">       <LAYER type="featureclass" id="10" >         <DATASET name="counties" type="polygon" workspace="shp_ws-2" />       </LAYER>       <SPATIALQUERY subfields="#ALL#" where="POP1999 &gt; 5000000" />     </GET_FEATURES>   </REQUEST> </ARCXML>

Example 3: When using projection elements.

<?xml version="1.0" encoding="UTF-8" ?> <ARCXML version="1.1">   <REQUEST>     <GET_FEATURES featurelimit="25" beginrecord="0" outputmode="xml" geometry="true" envelope="true" compact="true">       <LAYER id="4" />       <SPATIALQUERY subfields="#ALL#" where="POPULATION > 10000000" >         <FILTERCOORDSYS id="53030" />         <FEATURECOORDSYS id="53030" />         <SPATIALFILTER relation="area_intersection">           <ENVELOPE minx="-11395772" miny="930558" maxx="-3878142" maxy="6419621"/>         </SPATIALFILTER>       </SPATIALQUERY>     </GET_FEATURES>   </REQUEST> </ARCXML>

Example 4: When a dynamic layer with COORDSYS is used in the request.

<?xml version="1.0" encoding="UTF-8" ?> <ARCXML version="1.1"> <REQUEST>   <GET_FEATURES featurelimit="5" beginrecord="0" outputmode="xml" geometry="false" envelope="true">     <LAYER id="40" type="featureclass" >         <DATASET name="country" type="polygon" workspace="shp_ws-0" />       <COORDSYS id="4326" />     </LAYER>     <SPATIALQUERY subfields="CNTRY_NAME POP_CNTRY #SHAPE#" where="POP_CNTRY  > 100000000">       <FILTERCOORDSYS id="54030" />       <FEATURECOORDSYS id="54030" />       <SPATIALFILTER relation="area_intersection">         <ENVELOPE minx="-11395772" miny="930558" maxx="-3878142" maxy="6419621"/>       </SPATIALFILTER>     </SPATIALQUERY>   </GET_FEATURES> </REQUEST> </ARCXML>

Example 5: When using a dynamic buffer layer (European cities) and dynamic target layer (countries) to select features. In this example, both layers reference a new workspace.

<?xml version="1.0" encoding="UTF-8" ?> <ARCXML version="1.1">   <REQUEST>     <GET_FEATURES featurelimit="25" beginrecord="1" outputmode="xml" geometry="false" envelope="false">       <WORKSPACES>         <SHAPEWORKSPACE name="shp_ws-5" directory="<path to EUROPE ESRIDATA>" />         <SHAPEWORKSPACE name="shp_ws-6" directory="<path to WORLD ESRIDATA>" />       </WORKSPACES>       <LAYER type="featureclass" id="40">  <!-- cities in Europe directory -->         <DATASET name="cities" type="point" workspace="shp_ws-5" />       </LAYER>       <SPATIALQUERY subfields="#ALL#" >         <BUFFER distance="800" bufferunits="miles">           <TARGETLAYER id="41" type="featureclass" >  <!--countries in world directory-->             <DATASET name="country" type="polygon" workspace="shp_ws-6" />           </TARGETLAYER>           <SPATIALQUERY subfields="CNTRY_NAME" />         </BUFFER>         <SPATIALFILTER relation="area_intersection" >           <ENVELOPE minx="24.239598278335" miny="61.1549497847919" maxx="26.492109038737" maxy="63.3859397417503" />         </SPATIALFILTER>       </SPATIALQUERY>     </GET_FEATURES>   </REQUEST> </ARCXML>

Back to top