E OGC WMS Support in MapViewer

MapViewer supports the rendering of data delivered using the Open GIS Consortium (OGC) Web Map Service (WMS) protocol, specifically the WMS 1.1.1 and 1.3.0 implementation specifications. MapViewer supports the GetMap, GetFeatureInfo, and GetCapabilities requests as defined in the OGC document 01-068r3 and 06-042.

MapViewer does not currently support the optional Styled Layer Descriptor capability, and MapViewer will not function as a Cascading Map Server in this release.

This appendix contains the following major sections:

• Section E.1, "Setting Up the WMS Interface for MapViewer"

• Section E.2, "WMS Specification and Corresponding MapViewer Concepts"

• Section E.3, "Adding a WMS Map Theme"

E.1 Setting Up the WMS Interface for MapViewer

MapViewer is preconfigured to run as a WMS service. Internally, MapViewer translates all incoming WMS requests into proper XML requests to the MapViewer server. For example, the following HTTP request invokes the GetCapabilities service of a MapViewer server:

http://localhost:8888/mapviewer/wms?REQUEST=GetCapabilities&SERVICE=WMS&VERSION=1.1.1
or
http://localhost:8888/mapviewer/wms?REQUEST=GetCapabilities&SERVICE=WMS&VERSION=1.3.0

As shown in this example, the URL for the MapViewer WMS service is typically http://host:port/mapviewer/wms?, where host and port refer to the host and HTTP port of the MapViewer server. The context path /mapviewer/wms refers to the WMS interface of MapViewer.

Note:

All WMS requests must be on a single line, so ignore any line breaks that might appear in WMS request examples in this chapter.

E.1.1 Required Files

The following files are required for MapViewer WMS support: WMSFilter.jar and classgen.jar.

• The servlet filter and its required classes are packaged in WMSFilter.jar. This should be located in the $MAPVIEWER_HOME/web/WEB-INF/lib directory.

• The servlet filter also requires classgen.jar, which is part of the XML Developer's Kit (XDK) for Java. A standalone OC4J installation usually does not have this file; however, an Oracle Database or full Oracle Fusion Middleware installation will already have this file.

  If your system does not already have the classgen.jar file, use a classgen.jar file from the same XDK for Java version as the one that ships with your standalone OC4J version. Place this file in the $MAPVIEWER_HOME/web/WEB-INF/lib directory or in a directory that is in the library path for OC4J.

  The classgen.jar and xmlparserv2.jar files must be from the same XDK release, because the classgen.jar file depends on the xmlparserv2.jar file. Also, the XDK release for both files must be OC4J 10.0.0.3 or later, and preferably 10.1.2 or later.

E.1.2 Data Source Named wms

You must define a MapViewer data source named wms, unless every incoming WMS request explicitly specifies a datasource CGI parameter. All requests that do not specify the datasource parameter are by default directed to the data source named wms. For example, the GetCapabilities request will by default list all the available themes that are in the wms data source. (To configure the information returned by a GetCapabilities request, see Section 1.5.2.12.)

E.1.3 SDO to EPSG SRID Mapping File

By default, MapViewer uses the Oracle Spatial (SDO) native SRID (spatial reference ID) values when such information is requested in a WMS request such as GetCapabilities. The EPSG SRID values, however, are more widely used in WMS applications. To have MapViewer use EPSG SRID values when processing WMS requests and generating responses, specify a mapping file. This mapping file is a text file that tells MapViewer which SDO SRID values map to which EPSG SRID values. (Each pair of matching SRID values refers to the same spatial reference system.)

The mapping file contains lines where each line defines one pair of equivalent SRID values in the following format:

sdo_srid=epsg_srid

For example, the following lines define SDO SRID 8307 as equivalent to EPSG SRID 4326, and SDO SRID 81922 as equivalent to EPSG SRID 20248:

8307=4326
81922=20248

After you have created an SDO to EPSG mapping file, you can save it on the server where MapViewer is running, and specify its location in the MapViewer configuration file using the <sdo_epsg_mapfile> element in the <wms_config> element, as explained in Section 1.5.2.12.

E.2 WMS Specification and Corresponding MapViewer Concepts

This section describes the association between, or interpretation of, terms and concepts used in the WMS 1.1.1 and 1.3.0 specifications and MapViewer. It also includes some parameters that are specific to MapViewer but that are not in the WMS 1.1.1 and 1.3.0 specifications.

E.2.1 Supported GetMap Request Parameters

This section describes the supported GetMap request parameters and their interpretation by MapViewer. (Parameters that are specific to MapViewer and not mentioned in the WMS 1.1.1 and 1.3.0 specifications are labeled MapViewer-Only.) The supported parameters are in alphabetical order, with each in a separate subsection. Example E-1 shows some GetMap requests. (Each URL should be entered as a single string.)

Example E-1 GetMap Requests

http://localhost:8888/mapviewer/wms?REQUEST=GetMap&VERSION=1.1.1&FORMAT=image/gif&
SERVICE=WMS&BBOX=-121,37,-119,35&SRS=EPSG:4326&LAYERS=theme_demo_states,theme_
demo_counties,theme_demo_highways,theme_demo_cities&WIDTH=580&HEIGHT=500

http://localhost:8888/mapviewer/wms?REQUEST=GetMap&VERSION=1.3.0&FORMAT=image/gif&
SERVICE=WMS&BBOX=-121,37,-119,35&CRS=EPSG:4326&LAYERS=theme_demo_states,theme_
demo_counties,theme_demo_highways,theme_demo_cities&WIDTH=580&HEIGHT=500

http://localhost:8888/mapviewer/wms?request=GetMap&version=1.3.0&crs=none
&bbox=-122,36,-121,37&width=600&height=400&format=image/png&layers=theme_us_
states&mvthemes=<themes><theme%20name="theme_us_counties"/><theme%20name="theme_
us_road1"/></themes>&legend_
request=<legend%20bgstyle="fill:%23ffffff;stroke:%23ff0000"%20profile="medium"%20p
osition="SOUTH_EAST"><column><entry%20style="v.rb1"%20tab="1"/></column></legend>& 

The default data source for a GetMap request is WMS. That is, if you do not specify the DATASOURCE parameter in a GetMap request, it is assumed that a data source named WMS was previously created using the <add_data_source> element (described in Section 7.1.1) in a MapViewer administrative request.

The following optional GetMap parameters are not supported in the current release of MapViewer:

• TIME (time dimension)

• ELEVATION (elevation dimension)

• SLD and WFS URLs

The MapViewer-only parameters must contain valid XML fragments. Because these are supplied in an HTTP GET request, they must be appropriately encoded using a URL encoding mechanism. For example, replace each space ( ) with %20 and each pound sign (#) with %23. The following example shows the use of such encoding:

http://localhost:8888/mapviewer/wms?request=GetMap&version=1.1.1&srs=none&bbox=-12
2,36,-121,37&width=600&height=400&format=image/png&layers=theme_us_
states&mvthemes=<themes><theme%20name="theme_us_counties"/><theme%20name="theme_
us_road1"/></themes>&legend_
request=<legend%20bgstyle="fill:%23ffffff;stroke:%23ff0000"%20profile="medium"%20p
osition="SOUTH_EAST"><column><entry%20style="v.rb1"%20tab="1"/></column></legend>&

E.2.1.1 BASEMAP Parameter (MapViewer-Only)

The BASEMAP parameter specifies a named base map for the specified (or default) data source. If you specify both the BASEMAP and LAYERS parameters, all themes specified in the LAYERS parameters are added to the base map. Therefore, if you just want to get a map using a named base map, specify the BASEMAP parameter but specify an empty LAYERS parameter, as in the following examples:

REQUEST=GetMap&VERSION=1.1.1&BASEMAP=demo_
map&LAYERS=&WIDTH=500&HEIGHT=560&SRS=SDO:8307&BBOX=-122,36,-120,38.5&FORMAT=image/png

REQUEST=GetMap&VERSION=1.3.0&BASEMAP=demo_
map&LAYERS=&WIDTH=500&HEIGHT=560&CRS=SDO:8307&BBOX=-122,36,-120,38.5&FORMAT=image/png

E.2.1.2 BBOX Parameter

The BBOX parameter specifies the lower-left and upper-right coordinates of the bounding box for the data from the data source to be displayed. It has the format BBOX=minX,minY,maxX,maxY. For example: BBOX=-122,36,-120,38.5

E.2.1.3 BGCOLOR Parameter

The BGCOLOR parameter specifies background color for the map display using the RBG color value. It has the format 0xHHHHHH (where each H is a hexadecimal value from 0 to F). For example: BGCOLOR=0xF5F5DC (beige).

E.2.1.4 DATASOURCE Parameter (MapViewer-Only)

The DATASOURCE parameter specifies the name of the data source for the GetMap or GetFeatureInfo request. The default value is WMS. The specified data source must exist prior to the GetMap or GetFeatureInfo request. That is, it must have been created using the <add_data_source> MapViewer administrative request or defined in the MapViewer configuration file (mapViewerConfig.xml).

E.2.1.5 DYNAMIC_STYLES Parameter (MapViewer-Only)

The DYNAMIC_STYLES parameter specifies a <styles> element as part of the GetMap request. For information about the <styles> element, see Section 3.2.19.

E.2.1.6 EXCEPTIONS Parameter

For the EXCEPTIONS parameter, the only supported value is the default: EXCEPTIONS=application/vnd.ogc.se_xml for WMS 1.1.1 and EXCEPTIONS=XML for WMS 1.3.0. The exception is reported as an XML document conforming to the Service Exception DTD available at the following URLs:

http://schemas.opengis.net/wms/1.1.1/WMS_exception_1_1_1.dtd

http://schemas.opengis.net/wms/1.3.0/exceptions_1_3_0.xsd

The application/vnd.ogc.se_inimage (image overwritten with Exception message), and application/vnd.ogc.se_blank (blank image because Exception occurred) options are not supported.

E.2.1.7 FORMAT Parameter

The FORMAT parameter specifies the image format. The supported values are image/gif, image/jpeg, image/png, image/png8, and image/svg+xml.

The default value is image/png.

E.2.1.8 HEIGHT Parameter

The HEIGHT parameter specifies the height for the displayed map in pixels.

E.2.1.9 LAYERS Parameter

The LAYERS parameter specifies a comma-delimited list of predefined theme names to be used for the display. The specified values are considered to a be a case-sensitive, ordered, comma-delimited list of predefined theme names in a default data source (named WMS) or in a named data source specified by the parameter DATASOURCE=<name>. For example, LAYERS=THEME_DEMO_STATES,theme_demo_counties,THEME_demo_HIGHWAYS translates to the following <themes> element in a MapViewer map request:

<themes>
<theme name="THEME_DEMO_STATES"/>
<theme name="theme_demo_counties"/>
<theme name="THEME_demo_HIGHWAYS"/>
</themes>

If you want to specify both a base map and one or more LAYERS values, see the information about the BASEMAP parameter in Section E.2.1.1.

E.2.1.10 LEGEND_REQUEST Parameter (MapViewer-Only)

The LEGEND_REQUEST parameter specifies a <legend> element as part of the GetMap request. For information about the <legend> element, see Section 3.2.11.

E.2.1.11 MVTHEMES Parameter (MapViewer-Only)

The MVTHEMES parameter specifies a <themes> element as part of the GetMap request. For information about the <themes> element, see Section 3.2.21. The primary purpose for the MVTHEMES parameter is to support JDBC themes in a MapViewer request. The MVTHEMES parameter is not a substitute or synonym for the LAYERS parameter; you still must specify the LAYERS parameter.

E.2.1.12 REQUEST Parameter

The REQUEST parameter specifies the type of request. The value must be GetMap, GetFeatureInfo, or GetCapabilities.

E.2.1.13 SERVICE Parameter

The SERVICE parameter specifies the service name. The value must be WMS.

E.2.1.14 SRS (1.1.1) or CRS (1.3.0) Parameter

The SRS parameter (WMS 1.1.1) or the CRS parameter (WMS 1.3.0) specifies the spatial reference system (coordinate system) for MapViewer to use. The value must be one of the following: SDO:srid-value (where srid-value is a numeric Oracle Spatial SRID value), EPSG:4326 (equivalent to SDO:8307), or none (equivalent to SDO:0).

Except for EPSG:4326 (the standard WGS 84 longitude/latitude coordinate system), EPSG numeric identifiers are not supported. The namespace AUTO ( WMS 1.1.1) or AUTO2 (WMS 1.3.0), for projections that have an arbitrary center of projection, is not supported.

E.2.1.15 STYLES Parameter

The STYLES parameter is ignored. Instead, use the LAYERS parameter to specify predefined themes for the display.

E.2.1.16 TRANSPARENT Parameter

The TRANSPARENT=TRUE parameter (for a transparent image) is supported for PNG images, that is, with FORMAT=image/png, or FORMAT=image/png8 for indexed (8-bit) PNG format. MapViewer does not support transparent GIF (GIF89) images.

E.2.1.17 VERSION Parameter

The VERSION parameter specifies the WMS version number. The value must be 1.1.1 or 1.3.0.

E.2.1.18 WIDTH Parameter

The WIDTH parameter specifies the width for the displayed map in pixels.

E.2.2 Supported GetCapabilities Request and Response Features

A WMS GetCapabilities request to MapViewer should specify only the following parameters:

• REQUEST=GetCapabilities

• VERSION=1.1.1 or VERSION=1.3.0

• SERVICE=WMS

For example:

http://localhost:8888/mapviewer/wms?REQUEST=GetCapabilities&VERSION=1.1.1&SERVICE=WMS
or
http://localhost:8888/mapviewer/wms?REQUEST=GetCapabilities&VERSION=1.3.0&SERVICE=WMS

The response is an XML document conforming to the WMS Capabilities DTD available at the following, depending on the value of the VERSION parameter (1.1.1 or 1.3.0):

http://schemas.opengis.net/wms/1.1.1/WMS_MS_Capabilities.dtd

http://schemas.opengis.net/wms/1.3.0/capabilities_1_3_0.xsd

However, the current release of MapViewer returns an XML document containing the <Service> and <Capability> elements with the following information:

• The <Service> element is mostly empty, with just the required value of OGC:WMS for the <Service.Name> element. Support for more informative service metadata is planned for a future release of MapViewer.

• The <Capability> element has <Request>, <Exception>, and <Layer> elements.

• The <Request> element contains the GetCapabilities and GetMap elements that describe the supported formats and URL for an HTTP GET or POST operation.

• The <Exception> element defines the exception format. The Service Exception XML is the only supported format in this release. The <Exception> element returns an XML document compliant with the Service Exception DTD, but it does not report exceptions as specified in the implementation specification. The current release simply uses the CDATA section of a <ServiceException> element to return the OMSException returned by the MapViewer server.

• The <Layer> element contains a nested set of <Layer> elements. The first (outermost) layer contains a name (WMS), a title (Oracle WebMapServer Layers by data source), and one <Layer> element for each defined data source. Each data source layer contains a <Layer> element for each defined base map and one entry for each valid theme (layer) not listed in any base map. Each base map layer contains a <Layer> element for each predefined theme in the base map.

  Themes that are defined in the USER_SDO_THEMES view, that have valid entries in the USER_SDO_GEOM_METADATA view for the base table and geometry column, and that are not used in any base map will be listed after the base maps for a data source. These themes will have no <ScaleHint> element. They will have their own <LatLonBoundingBox> and <BoundingBox> elements.

The Content-Type of the response is set to application/vnd.ogc.wms_xml, as required by the WMS implementation specification.

Because the list of layers is output by base map, a given layer or theme can appear multiple times in the GetCapabilities response. For example, the theme THEME_DEMO_STATES, which is part of the base maps named DEMO_MAP and DENSITY_MAP, appears twice in Example E-2, which is an excerpt (reformatted for readability) from a GetCapabilities response.

Example E-2 GetCapabilities Response (Excerpt)

<Title>Oracle WebMapServer Layers by data source</Title>
<Layer>
 <Name>mvdemo</Name>
 <Title>Datasource mvdemo</Title>
   <Layer>
     <Name>DEMO_MAP</Name>
     <Title>Basemap DEMO_MAP</Title>
     <SRS>SDO:8307</SRS>
     <LatLonBoundingBox>-180,-90,180,90</LatLonBoundingBox>
. . .
   <Layer>
     <Name>DENSITY_MAP</Name>
     <Title>Basemap DENSITY_MAP</Title>
     <SRS>SDO:8307</SRS>
     <LatLonBoundingBox>-180,-90,180,90</LatLonBoundingBox>
       <Layer>
         <Name>THEME_DEMO_STATES</Name>
         <Title>THEME_DEMO_STATES</Title>
         <SRS>SDO:8307</SRS>
         <BoundingBox SRS="SDO:8307" minx="-180" miny="-90" maxx="180"
                      maxy="90" resx="0.5" resy="0.5"/>
         <ScaleHint min="50.0" max="4.0"/>
       </Layer>
. . .              
   </Layer>
   <Layer>
     <Name>IMAGE_MAP</Name>
     <Title>Basemap IMAGE_MAP</Title>
     <SRS>SDO:41052</SRS>
     <LatLonBoundingBox>-180,-90,180,90</ LatLonBoundingBox>
       <Layer>
         <Name>IMAGE_LEVEL_2</Name>
         <Title>IMAGE_LEVEL_2</Title>
         <SRS>SDO:41052</SRS>
         <BoundingBox SRS="SDO:41052" minx="200000" miny="500000" maxx="750000"
                    maxy="950000" resx="0.5" resy="0.5"/>
         <ScaleHint min="1000.0" max="0.0"/>
       </Layer>
. . .    
   </Layer>

In Example E-2, the innermost layer describes the IMAGE_LEVEL_2 theme. The <ScaleHint> element lists the min_scale and max_scale values, if any, for that theme in the base map definition. For example, the base map definition for IMAGE_MAP is as follows:

SQL> select definition from user_sdo_maps where name='IMAGE_MAP';
 
DEFINITION
------------------------------------------------------------------------
<?xml version="1.0" standalone="yes"?>
<map_definition>
  <theme name="IMAGE_LEVEL_2" min_scale="1000.0" max_scale="0.0"/>
  <theme name="IMAGE_LEVEL_8" min_scale="5000.0" max_scale="1000.0"/>
  <theme name="MA_ROAD3"/>
  <theme name="MA_ROAD2"/>
  <theme name="MA_ROAD1"/>
  <theme name="MA_ROAD0"/>
</map_definition>

In the innermost layer, the <SRS> and <BoundingBox> elements identify the SRID and the DIMINFO information for that theme's base table, as shown in the following Spatial metadata query:

SQL> select srid, diminfo from user_sdo_geom_metadata, user_sdo_themes 
  2  where name='IMAGE_LEVEL_2' and 
  3  base_table=table_name and
  4  geometry_column=column_name ;
 
      SRID
----------
DIMINFO(SDO_DIMNAME, SDO_LB, SDO_UB, SDO_TOLERANCE)
--------------------------------------------------------------------------------
     41052
SDO_DIM_ARRAY(SDO_DIM_ELEMENT('X', 200000, 500000, .5), SDO_DIM_ELEMENT('Y', 750
000, 950000, .5))

In Example E-2, the <Layer> element for a base map has an <SRS> element and a <LatLonBoundingBox> element. The <SRS> element is empty if all layers in the base map definition do not have the same SRID value specified in the USER_SDO_GEOM_METADATA view. If they all have the same SRID value (for example, 41052), the SRS element contains that value (for example, SDO:41052). The required <LatLonBoundingBox> element currently has default values (-180,-90,180,90). When this feature is supported by MapViewer, this element will actually be the bounds specified in the DIMINFO column of the USER_SDO_GEOM_METADATA view for that layer, converted to geodetic coordinates if necessary and possible.

All layers are currently considered to be opaque and queryable. That is, all layers are assumed to be vector layers, and not GeoRaster, logical network, or image layers.

E.2.3 Supported GetFeatureInfo Request and Response Features

This section describes the supported GetFeatureInfo request parameters and their interpretation by MapViewer. Example E-3 shows some GetFeatureInfo requests.

Example E-3 GetFeatureInfo Request

http://localhost:8888/mapviewer/wms?REQUEST=GetFeatureInfo&VERSION=1.1.1&BBOX=0,-0
.0020,0.0040&SRS=EPSG:4326&LAYERS=cite:Lakes,cite:Forests&WIDTH=200&HEIGHT=100&INF
O_FORMAT=text/xml&QUERY_LAYERS=cite:Lakes,cite:Forests&X=60&Y=60

http://localhost:8888/mapviewer/wms?REQUEST=GetFeatureInfo&VERSION=1.3.0
&BBOX=0,-0.0020,0.0040&CRS=EPSG:4326&LAYERS=cite:Lakes,cite:Forests&WIDTH=200&HEIGHT=100
&INFO_FORMAT=text/xml&QUERY_LAYERS=cite:Lakes,cite:Forests&I=60&J=60

The response is an XML document and the Content-Type of the response is text/xml. Example E-4 is a response to a GetFeatureInfo request in Example E-3.

Example E-4 GetFeatureInfo Response

<?xml version="1.0" encoding="UTF-8" ?>
<GetFeatureInfo_Result>
  <ROWSET name="cite:Lakes">
    <ROW num="1">
      <ROWID>AAAK22AAGAAACUiAAA</ROWID>
    </ROW>
  </ROWSET>
  <ROWSET name="cite:Forests">
    <ROW num="1">
      <FEATUREID>109</FEATUREID>
    </ROW>
  </ROWSET>
</GetFeatureInfo_Result>

Most of the following sections describe parameters supported for a GetFeatureInfo request. (Parameters that are specific to MapViewer and not mentioned in the WMS 1.1.1 specification are labeled MapViewer-Only.) Section E.2.3.10 explains how to query attributes in a GetFeatureInfo request.

E.2.3.1 GetMap Parameter Subset for GetFeatureInfo Requests

A GetFeatureInfo request contains a subset of a GetMap request (BBOX, SRS [1.1.1] or CRS [1.3.0], WIDTH, HEIGHT, and optionally LAYERS parameters). These parameters are used to convert the X, Y (1.1.1) or I, J (1.3.0) point from screen coordinates to a point in the coordinate system for the layers being queried. It is assumed all layers are in the same coordinate system, the one specified by the SRS parameter.

E.2.3.2 EXCEPTIONS Parameter

The only supported value for the EXCEPTIONS parameter is the default: application/vnd.ogc.se_xml for WMS 1.1.1 or xml for WMS 1.3.0. That is, only Service Exception XML is supported. The exception is reported as an XML document conforming to the Service Exception DTD available at the following, depending on the version (1.1.1 or 1.3.0):

http://schemas.opengis.net/wms/1.1.1/WMS_exception_1_1_1.dtd

http://schemas.opengis.net/wms/1.3.0/exceptions_1_3_0.xsd

E.2.3.3 FEATURE_COUNT Parameter

The FEATURE_COUNT parameter specifies the maximum number of features in the result set. The default value is 1. If more features than the parameter's value interact with the query point (X, Y), then an arbitrary subset (of the size of the parameter's value) of the features is returned in the result set. That is, a GetFeatureInfo call translates into a query of the following general form:

SELECT <info_columns> FROM <layer_table>
  WHERE SDO_RELATE(<geom_column>, 
    <query_point>, 'mask=ANYINTERACT')='TRUE'
  AND ROWNUM <= FEATURE_COUNT;

E.2.3.4 INFO_FORMAT Parameter

The value of the INFO_FORMAT parameter is always text/xml.

E.2.3.5 QUERY_LAYERS Parameter

The QUERY_LAYERS parameter specifies a comma-delimited list of layers to be queried. If the LAYERS parameter is specified, the QUERY_LAYERS specification must be a subset of the list specified in the LAYERS parameter.

If the QUERY_LAYERS parameter is specified, any BASEMAP parameter value is ignored.

E.2.3.6 QUERY_TYPE Parameter (MapViewer-Only)

The QUERY_TYPE parameter limits the result set to a subset of possibly qualifying features by specifying one of the following values:

• at_point: returns only the feature at the specified point.

• nn: returns only the nearest neighbor features, with the number of results depending on the value of the FEATURE_COUNT parameter value (see Section E.2.3.3). The result set is not ordered by distance.

• within_radius (or within_distance, which is a synonym): returns only results within the distance specified by the RADIUS parameter value (see Section E.2.3.7), up to the number matching the value of the FEATURE_COUNT parameter value (see Section E.2.3.3). The result set is an arbitrary subset of the answer set of potential features within the specified radius. The result set is not ordered by distance.

E.2.3.7 RADIUS Parameter (MapViewer-Only)

The RADIUS parameter specifies the radius of the circular search area for a query in which the QUERY_TYPE parameter value is within_radius (see Section E.2.3.6). If you specify the RADIUS parameter, you must also specify the UNIT parameter (see Section E.2.3.8).

E.2.3.8 UNIT Parameter (MapViewer-Only)

The UNIT parameter specifies the unit of measurement for the radius of the circular search area for a query in which the QUERY_TYPE parameter value is within_radius (see Section E.2.3.6). The value must be a valid linear measure value from the SHORT_NAME column of the SDO_UNITS_OF_MEASURE table, for example: meter, km, or mile.

If you specify the UNIT parameter, you must also specify the RADIUS parameter (see Section E.2.3.7).

E.2.3.9 X and Y or I and J Parameters

The X and Y (WMS 1.1.1) or I and J (WMS 1.3.0) parameters specify the x-axis and y-axis coordinate values (in pixels), respectively, of the query point.

E.2.3.10 Specifying Attributes to Be Queried for a GetFeatureInfo Request

In a GetFeatureInfo request, the styling rule for each queryable layer (theme) must contain a <hidden_info> element that specifies which attributes are queried and returned in the XML response. The <hidden_info> element is the same as the one used for determining the attributes returned in an SVG map request.

An example of such a styling rule as follows:

SQL> select styling_rules from user_sdo_themes where name='cite:Forests';
 
STYLING_RULES
--------------------------------------------------------------------------------
<?xml version="1.0" standalone="yes"?>
<styling_rules>
  <hidden_info>
          <field column="FID" name="FeatureId"/>
       </hidden_info>
  <rule>
    <features style="C.PARK FOREST">  </features>
    <label column="NAME" style="T.PARK NAME"> 1 </label>
  </rule>
</styling_rules>

This styling rule specifies that if cite:Forests is one of the QUERY_LAYERS parameter values in a GetFeatureInfo request, the column named FID is queried, and its tag in the response document will be <FEATUREID>. The tag is always in uppercase. If no <hidden_info> element is specified in the styling rules for the theme's query layer, then the rowid is returned. In Example E-4, the styling rule for the cite:Lakes layer has no <hidden_info> element; therefore, the default attribute ROWID is returned in the XML response. The cite:Forests layer, however, does have a <hidden_info> element, which specifies that the attribute column is FID, and that its tag name, in the response document, should be <FEATUREID>.

E.3 Adding a WMS Map Theme

You can add a WMS map theme to the current map request. The WMS map theme is the result of a GetMap request, and it becomes an image layer in the set of layers (themes) rendered by MapViewer.

To add a WMS map theme, use the WMS-specific features of either the XML API (see Section E.3.1) or the JavaBean-based API (see Section E.3.4).

E.3.1 XML API for Adding a WMS Map Theme

To add a WMS map theme to the current map request using the MapViewer XML API, use the <wms_getmap_request> element in a <theme> element.

For better performance, the <wms_getmap_request> element should be used only to request a map image from a Web map server (WMS) implementation. That is, the <service_url> element in a <wms_getmap_request> element should specify a WMS implementation, not a MapViewer instance. If you want to specify a MapViewer instance (for example, specifying <service_url> with a value of http://mapviewer.mycorp.com:8888/mapviewer/wms), consider using a MapViewer predefined theme or a JDBC theme in the <themes> element instead of using a <wms_getmap_request> element.

The following example shows the general format of the <wms_getmap_request> element within a <theme> element, and it includes some sample element values and descriptive comments:

<themes>
  <theme>
     <wms_getmap_request isBackgroundTheme="true">
           <!-- The wms_getmap_request theme is rendered in the order it 
                 appears in the theme list unless isBackgroundTheme is "true". 
           -->
          <service_url> http://wms.mapsrus.com/mapserver </service_url>
          <version> 1.1.1 </version>
            <!-- version is optional. Default value is "1.1.1".
            -->
          <layers> Administrative+Boundaries,Topography,Hydrography </layers>
           <!— layers is a comma-delimited list of names. 
              If layer names contain spaces, use '+' instead of a space -->
           <!— styles is optional. It is a comma-delimited list, and it must
              have the same number of  names as the layer list, if specified. 
              If style names contain spaces, use '+' instead of a space -->
          <styles/>
          <srs> EPSG:4326 </srs>
          <format> image/png </format>
          <transparent> true </transparent>
          <bgcolor> 0xffffff </bgcolor>
          <exceptions> application/vnd.ogc.se_inimage </exceptions>
          <vendor_specific_parameters>
               <!-- one or more <vsp> elements each containing 
                     a <name> <value> pair  -->
               <vsp>
                    <name> datasource </name>
                    <value> mvdemo </value>
                 </vsp>
          <vendor_specific_parameters>
     <wms_getmap_request>
  </theme>
</themes>

The following attribute and elements are available with the <wms_getmap_request> element:

• The isBackgroundTheme attribute specifies whether or not this theme should be rendered before the vector layers. The default value is false.

• The <service_url> element specifies the URL (without the service parameters) for the WMS service. Example: http://my.webmapserver.com/wms

• The <version> element specifies the WMS version number. The value must be one of the following: 1.0.0, 1.1.0, 1.1.1 (the default), or 1.3.0.

• The <layers> element specifies a comma-delimited list of layer names to be included in the map request.

• The <styles> element specifies a comma-delimited list of style names to be applied to the layer names in layers.

• The <srs> element specifies the coordinate system (spatial reference system) name. The default value is EPSG:4326.

• The <format> element specifies the format for the resulting map image. The default value is image/png.

• The <transparent> element specifies whether or not the layer or layers being added should be transparent in the resulting map image. The default value is false. To make the layer or layers transparent, specify true.

• The <bgcolor> element specifies the RGB value for the map background color. Use hexadecimal notation for the value, for example, 0xAE75B1. The default value is 0xFFFFFF (that is, white).

• The <exceptions> element specifies the format for server exceptions. The default value is application/vnd.ogc.se_inimage.

• The <vendor_specific_parameters> element contains one or more <vsp> elements, each of which contains a <name> element specifying the parameter name and a <value> element specifying the parameter value.

Example E-5 shows the <wms_getmap_request> element in a map request.

Example E-5 Adding a WMS Map Theme (XML API)

<?xml version="1.0" standalone="yes"?>
<map_request
  title="Raster WMS Theme and Vector Data"
  datasource="mvdemo" srid="0"
  width="500"
  height="375"
  bgcolor="#a6caf0"
  antialiase="true"
  mapfilename="wms_georaster" format="PNG_URL">
  <center size="185340.0">
    <geoFeature>
      <geometricProperty typeName="center">
        <Point>
          <coordinates>596082.0,8881079.0</coordinates>
        </Point>
      </geometricProperty>
    </geoFeature>
  </center>
  <themes>
    <theme name="WMS_TOPOGRAPHY" user_clickable="false"  >
       <wms_getmap_request isBackgroundTheme="true">
         <service_url> http://wms.mapservers.com:8888/mapserver/wms </service_url>
         <layers> TOPOGRAPHY </layers>
         <srs> EPSG:29190 </srs>
         <format> image/png </format>
         <bgcolor> 0xa6caf0 </bgcolor>
         <transparent> true </transparent>
         <vendor_specific_parameters>
           <vsp>
              <name> ServiceType </name>
              <value> mapserver </value>
           </vsp>
         </vendor_specific_parameters>
       </wms_getmap_request>
    </theme>
    <theme name="cl_theme" user_clickable="false">
       <jdbc_query  spatial_column="geom" render_style="ltblue" 
         jdbc_srid="82279" datasource="mvdemo"
         asis="false">select geom from classes where vegetation_type = 'forests'
       </jdbc_query>
     </theme>
  </themes>
  <styles>
    <style name="ltblue">
      <svg width="1in" height="1in">
       <g class="color" 
          style="stroke:#000000;stroke-opacity:250;fill:#33ffff;fill-opacity:100">
          <rect width="50" height="50"/>
       </g>
      </svg>
    </style>
  </styles>
</map_request>

E.3.2 Predefined WMS Map Theme Definition

The predefined XML definition for a WMS theme uses the same structure of the parameters in Section E.3.1, and adds the optional capabilities_url attribute, which is used by Map Builder when editing a WMS theme. If the capabilities_url attribute is defined, Map Builder will issue a GetCapabilities request to populate some UI elements in the editor page.

Example E-6 shows how to create a predefined WMS theme in the metadata. The base table and base column names can be any values, and in this example 'WMS' is used for both.

Example E-6 Creating a Predefined WMS Theme

INSERT INTO user_sdo_themes  VALUES (
  'PRED_WMS_THEME',
  'WMS data',
  'WMS',
  'WMS',   '<?xml version="1.0" standalone="yes"?>
   <styling_rules theme_type="wms">
     <service_url> http://sampleserver1b.arcgisonline.com/arcgis/services/Specialty/ESRI_StateCityHighway_USA/MapServer/WMSServer </service_url>
     <layers> 0,1,2 </layers>
     <version> 1.3.0 </version>
     <srs> CRS:84 </srs>
     <format> image/png </format>
     <bgcolor> 0xA6CAF0 </bgcolor>
     <transparent> false </transparent>
     <styles> +,+,+ </styles>
     <exceptions> xml </exceptions>
     <capabilities_url> http://sampleserver1.arcgisonline.com/ArcGIS/services/Specialty/ESRI_StateCityHighway_USA/MapServer/WMSServer? </capabilities_url>
   </styling_rules>');

E.3.3 Authentication with WMS Map Themes

For a WMS server that requires authentication for access to the WMS data, the following must be included in the theme definition:

• <user> element specifying the user name

• <password> element specifying the user password

  If you use the Map Builder tool to create a WMS map theme, the password value will be automatically encrypted. Figure E-1 shows the use of the Map Builder tool to create a WMS theme with authentication information. In this figure, the Authentication option is checked (enabled), and User and Password are specified.

  Figure E-1 Using Map Builder to Specify Authentication with a WMS Theme

  
  Description of "Figure E-1 Using Map Builder to Specify Authentication with a WMS Theme"
  
  

Example E-7 shows how to create a WMS theme that includes authentication information.

Example E-7 WMS Theme with Authentication Specified

<?xml version="1.0" standalone="yes"?>
<styling_rules theme_type="wms">
    <service_url> http://localhost:7001/mapviewer/wms </service_url>
    <user> wmsuser </user>
    <password> ******* </password>
    <layers> THEME_DEMO_STATES </layers>
    <version> 1.1.1 </version>
    <srs> EPSG:4326 </srs>
    <format> image/png </format>
    <bgcolor> 0xA6CAF0 </bgcolor>
    <transparent> true </transparent>
    <exceptions> application/vnd.ogc.se_xml </exceptions>
    <vendor_specific_parameters>
        <vsp>
            <name> datasource </name>
            <value> mvdemo </value>
    </vsp>
  </vendor_specific_parameters>
    <capabilities_url> http://localhost:7001/mapviewer/wms? </capabilities_url>
</styling_rules>

E.3.4 JavaBean-Based API for Adding a WMS Map Theme

To add a WMS map theme to the current map request using the MapViewer JavaBean-based API, use the addWMSMapTheme method.

This method should be used only to request a map image from a Web map server (WMS) implementation. That is, the serviceURL parameter should specify a WMS implementation, not a MapViewer instance.

The addWMSMapTheme method has the following format:

addWMSMapTheme(String name, String serviceURL, String isBackgroundTheme,
               String version, String[] layers, String[] styles, 
               String srs, String format, String transparent,
               String bgcolor, String exceptions,
               Object[] vendor_specific_parameters
               );

The name parameter specifies the theme name.

The serviceURL parameter specifies the URL (without the service parameters) for the WMS service. Example: http://my.webmapserver.com/wms

The isBackgroundTheme parameter specifies whether or not this theme should be rendered before the vector layers. The default value is false.

The version parameter specifies the WMS version number. The value must be one of the following: 1.0.0, 1.1.0, or 1.1.1 (the default).

The layers parameter specifies a comma-delimited list of layer names to be included in the map request.

The styles parameter specifies a comma-delimited list of style names to applied to the layer names in layers.

The srs parameter specifies the coordinate system (spatial reference system) name. The default value is EPSG:4326.

The format parameter specifies the format for the resulting map image. The default value is image/png.

The transparent parameter specifies whether or not the layer or layers being added should be transparent in the resulting map image. The default value is false. To make the layer or layers transparent, specify true.

The bgcolor parameter specifies the RGB value for the map background color. Use hexadecimal notation for the value, for example, 0xAE75B1. The default value is 0xFFFFFF (that is, white).

The exceptions parameter specifies the format for server exceptions. The default value is application/vnd.ogc.se_inimage.

The vendor_specific_parameters parameter specifies a list of vendor-specific parameters. Each element in the object array is a String array with two strings: parameter name and value. Example: vsp = new Object[]{new String[]{"DATASOURCE", "mvdemo"}, //param 1 new String[]{"antialiasing", "true"} //param 2