Getmap Request |
The main request parameters of GetMap are as following:
Table 1 The Parameters of a GetMap Request
| Request Parameters | O/M | Description |
| VERSION=version |
Mandatory |
Request version numbers. |
| REQUEST=GetMap |
Mandatory |
Request names. For GetMap, the value GetMap shall be used. (In WMS version 1.0.0, the value of this parameter was "map". That value is now deprecated, but for backwards compatibility a post-1.0.0 server should accept either form without issuing a Service Exception). |
| LAYERS=layer_list |
Optional (The SLD or SLD_BODY must be included if there is not LAYERS/STYLES in the request.) |
Comma-separated list of one or more map layers. Optional if SLD parameter is present. A WMS shall render the requested layers by drawing the leftmost in the list bottommost, the next one over that, and so on. Layer names must be values of Name elements declared in documents returned by the GetCapabilities operation. (It is not allowed to request Layer with only Title attribute but without Name attribute). If the client requests layers without Name attribute or layers that do not exist, the server will return an exception information whose Code is LayerNotDefined. |
| STYLES=style_list |
Optional (The SLD or SLD_BODY must be included if there is not LAYERS/STYLES in the request.) |
Comma-separated list of one rendering style per requested layer. There is a one-to-one correspondence between the values in the LAYERS parameter and the values in the STYLES parameter. A server shall throw an exception (code=StyleNotDefined) if an unadvertised Style is requested. Users can request the layer style predefined by server through Style Name parameter, and also can request the customized layer style through SLD parameter. The priority and match relationship between the LAYERS/STYLES parameter pair and SLD(SLD_BODY), please see Using SLD。 |
| SLD=sld_xml_uri |
Optional (The LAYERS/STYLES must be included if there is neither SLD nor SLD_BODY in the request.) |
The URI of the SLD document. For details, see Using SLD。 SLD is a user-defined layer style sheet. This URI has to be accessible to WMS service. |
| SLD_BODY=sld_xml_body |
Optional (The LAYERS/STYLES must be included if there is neither SLD nor SLD_BODY in the request.) |
The specific content of SLD document. For details, see Using SLD。 |
| SRS=namespace:identifier |
Mandatory |
Spatial Reference System. This parameter value should be SRS declared by the server in the GetCapabilities operation. Support for spatial reference systems, see The coordinate reference sytem for publishing supported by iServer OGC services. |
| BBOX=minx,miny,maxx,maxy |
Mandatory |
Bounding box corners (lower left, upper right) in SRS units. Bounding box, the value of the BBOX parameter in a GetMap request is a list of comma-separated numbers of the form "minx,miny,maxx,maxy". They represent minimum X, minimum Y, maximum X, maximum Y of area coordinates in the specified SRS respectively. |
| WIDTH=output_width |
Mandatory |
Width in pixels of map picture. |
| HEIGHT=output_height |
Mandatory |
Pixel heights of map pictures. |
| FORMAT=output_format |
Mandatory |
Output formats of maps. One of Format in GetMap declared in capabilities documents of the WMS server. |
| TRANSPARENT=TRUE|FALSE |
Optional |
Whether the map background is transparent (the default is FALSE). |
| BGCOLOR=color_value |
Optional |
Hexadecimal red-green-blue color values of background colors (the default is 0xFFFFFF). |
| EXCEPTIONS=exception_format |
Optional |
The format in which exceptions are to be reported by the WMS (default=SE_XML). This parameter value must be one of Exception Format declared in capabilities documents of the WMS server. |
| TIME=time |
Optional |
Time value of layer desired. SuperMap iServer has not realized this functionality at present. |
| ELEVATION=elevation |
Optional |
Elevations of layers that are expected to get. SuperMap iServer has not realized this functionality at present. |
| Other sample dimension(s) |
Optional |
Value of other dimensions as appropriate. SuperMap iServer has not realized this functionality at present. |
| Vendor-specific parameters |
Optional |
Optional experimental parameters. SuperMap iServer has not realized this functionality at present. |
Note:The case of parameters is not mandatory, and request parameters can be arranged in an arbitrary order.
Request methods of the GetMap operation are as follows:
<ServiceRoot>?VERSION=version&REQUEST=GetMap&LAYERS=&STYLES=&SRS=&BBOX=&WIDTH=&HEIGHT=&FORMAT=
ServiceRoot is the service URI root directory. Please se Setting the Service URI.
For example, when the local SuperMap iServer WMS 1.1.1 service has been successfully started, the URI to access the GetMap operation is URI: http://localhost:8090/iserver/services/maps/wms111/WorldMap_Day?VERSION=1.1.1&REQUEST=GetMap&layers=0.10&STYLES=World&SRS=EPSG:4326&BBOX=-180.0,-90.0,180.0,90.0&WIDTH=800&HEIGHT=400&FORMAT=image/png
Where "STYLE=WORLD" means rendering the layer by using the pre-defined sytle named World in the WMS service. If the STYLE is empty or STYLE=Default Style, it means requesting the default style of WMS layer. The default layer style is also listed in Capabilities document, named Default Style, please see GetCapabilities Response example。