GetCapabilities Response |
After executing the GetCapabilities operation, the server-side will return a metadata document in XML format that describes the WFS 2.0.0 service. The document mainly includes several components, including service metadata, service provider, service Competency, feature types, and filters, all of which are essential parts.
ServiceIdentification is the metadata of a specific service and the overall description of the service. It includes three mandatory elements: Title, ServiceType, and ServiceType Version, as well as some optional elements: Profile, Abstract, Keywords, Fees, and AccessConstraints.
Table 1 Service Identification Element
| Element name | Whether it is required | Description |
|
Title |
Yes |
Service title. A short description of the service, which can be one or more. |
|
ServiceType |
Yes |
service type. Request a WFS 2.0.0 service with a service type value of "WFS". |
|
ServiceTypeVersion |
Yes |
Service type version number. Request the WFS 2.0.0 service with a service type version number of "2.0.0". |
|
Profile |
No |
WFS Application Profile Identifier. This element is not currently included in the results returned by SuperMap iServer. |
|
Abstract |
No |
Summary of services. Provides a brief description of the server information. This element is not currently included in the results returned by SuperMap iServer. |
|
Keywords |
No |
Keyword. One or more common words or phrases that describe the server. There is no order between multiple words or phrases. This element is not currently included in the results returned by SuperMap iServer. |
|
Fees |
No |
Server costs. If the server has no usage charges, this element can be ignored. If the element is used, a value of none (case-insensitive) means free. This element is not currently included in the results returned by SuperMap iServer. |
|
AccessConstraints |
No |
Access restrictions. If no access restrictions are applied by the server, they can be ignored. If this element is used, a value of none (case-insensitive) indicates no access restrictions. If this element is used, the content of the element does not have a precise syntax definition, and the client can display user information and behavior content. This element is not currently included in the results returned by SuperMap iServer. |
ServiceProvider is the information about the service provider, including ProviderName, ProviderSite, and ServiceContact elements.
Table 2 Service Provider Elements
| Element name | Whether it is required | Description |
|
ProviderName |
Yes |
Provider name. It is the unique identifier for the service provider. |
|
ProviderSite |
Yes |
Provider address. |
|
ServiceContact |
Yes |
Contact information for the service provider. |
OperationsMetadata describes all the request operations supported by the current service and the corresponding URI for each request operation. The OperationsMetadata element must contain one or more Operation elements, with each Operation element corresponding to an operation. The OperationsMetadata element can also contain zero or more Constraint elements, with each Constraint element representing a constraint condition. The element descriptions of OperationsMetadata are shown in Table 3.
Table 3 Operations Metadata element
| Element name | Whether it is required | Description |
| Operation |
Yes |
Operation. It is used to identify the operation supported by the service. Each Operation node corresponds to an operation, which is identified by the name attribute, such as <Operation name="GetCapabilities">. The details of Operation are shown in Table 4 below. |
|
Parameter |
No |
Parameter. Valid domain that specifies one or more operations supported by the service. The name attribute identifies the parameter name; the Value element gives the valid value for the parameter. These parameters may be input and output parameters in the operation. This element is not currently included in the results returned by SuperMap iServer. |
| Constraint |
Yes |
Limitations. Valid domain restriction for non-parametric attributes applied to this server. The name attribute identifies the non-parametric attribute name. DefaultValue The default value for this attribute is TRUE or FALSE given in the element. |
| ExtendedCapabilities |
No |
Scalability. It is a description about the additional capabilities of servers and software. This element is not currently included in the results returned by SuperMap iServer. |
Each Operation element must contain one or more DCPs (Distributed Computing Platform) information. You can also include Parameter, Constraint, and Metadata parameters.
| Element name | Whether it is required | Description |
| name |
Yes |
Operation name. Each Operation element has an operation name, such as GetCapabilities. It is expressed as <Operation name="GetCapabilities">. |
| DCP |
Yes |
Distributed computing platform information for the operation. Each Operation element can contain one or more DCP elements. Since at present only defined HTTP DCP, so each Operation contains only one DCP element, HTTP. Typically one of the WFS services The HTTP element should contain at least a Get or a Post or a Get and a Post to indicate which request methods the service supports. |
| Parameter |
Yes |
Parameter. Used to specify the valid fields for this operation. The name attribute identifies the parameter name; the Value element gives the valid value for the parameter. These parameters may be input and output parameters in the operation. The GetCapabilities operation is expressed as follows: <ows:Parameter name="AcceptVersions"> <ows:AllowedValues> <ows:Value>2.0.0</ows:Value> </ows:AllowedValues> </ows:Parameter> If the valid domain of a parameter is specified in a specific Operation, the valid domain of the parameter with the same name in OperationsMetadata will be overwritten. |
| Constraint |
No |
Limitations. Valid domain restriction for non-parametric attributes applied to this server. The name attribute identifies the non-parametric attribute name. DefaultValue The default value for this attribute is TRUE or FALSE given in the element. If the valid domain of a non-parameter attribute is restricted in a specific Operation, the Operations Metadata The valid domain limit for a non-parameter attribute with the same name in is overridden. This element is not currently included in the results returned by SuperMap iServer. |
| Metadata |
No |
Metadata. Metadata about the current operation and its implementation. This element is not currently included in the results returned by SuperMap iServer. |
The FeatureTypeList element enumerates all the feature types that this WFS 2.0.0 service can provide. The TypeList element can contain multiple EigenType elements, each corresponding to a feature type. The description of the EigenType element is shown in the following table:
Table 5 FeatureType Element
| Element name | Whether it is required | Description |
|
Name |
Yes |
Feature type name. The element type is the type specified in the namespace. |
|
Title |
Yes |
Feature title. A short description of the feature type. |
|
Abstract |
No |
Summary of elements. A description with more information about the feature type. This element is not currently included in the results returned by SuperMap iServer. |
|
Keywords |
No |
Keyword. Short words for directory searches. This element is not currently included in the results returned by SuperMap iServer. |
|
DefaultCRS |
Yes |
Default coordinate reference system. If a coordinate reference system is not specified in the query or transaction request, the WFS service uses this default coordinate reference system to represent the geographic location of the spatial feature, such as sending a GetFeature When the request does not specify a CRS value with the srsName attribute of the Query element, any spatial attribute of the requested element responds with a default CRS value. CRS should be encoded using the URL format. If DefaultCRS and internally stored CRS are different, then WFS should support DefaultCRS and internally stored CRS Convert between. The impact of this conversion should be considered when data accuracy is required. |
|
OtherCRS |
No |
Other coordinate reference systems. This element is used to represent the transaction and other coordinate reference systems supported by the query request operation. Supported CRS means that WFS supports OtherCRS And the space attribute exchange is carried out between the space attribute and the internally stored CRS. The impact of this conversion should be considered when data accuracy is required. This element is not currently included in the results returned by SuperMap iServer. |
|
NoCRS |
No |
No coordinate reference system. This element should be used by feature types that do not have spatial attributes. Therefore, feature types that use this element do not have CRSs. Features and collections of features do not have to have spatial attributes. NoCRS is not equivalent to "Unknown CRS" and therefore cannot be used where the semantics are "Unknown CRS". This element can only be used as an identifier, so there is no element or attribute content. |
|
OutputFormats |
No |
Output format. This element is a list of MIME types that represent the supported output formats for that feature type. If the element is not specified, it represents a Get Feature All output formats listed for the operation are supported for this feature type. This element is not currently included in the results returned by SuperMap iServer. |
|
WGS84BoundingBox |
Yes |
WGS 84 bounding box. The smallest rectangle defined in the WGS 84 coordinate system that encloses the data set, expressed in latitude and longitude coordinates, with longitude first. The WGS 84 bounding box may be approximate, but should be as accurate as possible. |
|
MetadataUR |
No |
Metadata. WFS can use zero or more MetadataUR elements to provide detailed metadata for a particular feature type of data. You can use XLink:href The element references any metadata. This element is not currently included in the results returned by SuperMap iServer. |
|
ExtendedDescription |
No |
Extend the description. By using the ExtendedDescription element, there is no need to redefine the Capabilities schema document, WFS You can add elements that describe the feature type. The ExtendedDescription element includes one or more Element elements. Element element contains A name attribute, a type attribute, and a list of extended description element names. Where the name attribute is used to specify the name of the description element of the extension, and the type Attribute is used to specify the type of the extended description element list, and the type must be obtained from the built-in list defined in the XML Schema. This element is not currently included in the results returnedby SuperMap iServer. |
FilterCapabilities are used to declare expressions that restrict query operations in advance. Client applications can check for Capabilities contents of the FilterCapabilities section of the document to determine which operations and types are supported by the Filter Expression Processor. The FilterCapabilities elements are shown in the following table:
Table 5 Filter Capabilities Element
| The name of the element | Whether it is required |
| Conformance |
Yes |
|
idCapabilities |
Yes |
| ScalarCapabilities |
Yes |
| SpatialCapabilities |
Yes |
| TemporalCapabilities |
No |
| AvailableFunctions |
No |
| ExtendedCapabilities |
No |
Conformance is a list of constraints that can limit the valid fields of non parametric attributes applied to this server, allowing for multiple Constraint elements, each representing a constraint method. Non parametric attribute names can be identified by the name attribute of the Constraint element, and the default value of this attribute, TRUE/False, is specified in the DefaultValue element.
The response result of the request sample is as follows: