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Service Metadata

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The WWSAPI service host supports WS-MetadataExchange for its endpoints. You enable such metadata exchange on the service host with the following steps:

Specifying Metadata documents / Service name on the Service Host

The first step is to specify the metadata documents on the service host. Do this by gathering the individual documents as an array of WS_XML_STRING*'s. These strings can be XML Schema, WSDL or WS-Policy document. This is specified through the WS_SERVICE_PROPERTY_METADATA property.

Optionally, an application can also specify the service name and namespace as part of the WS_SERVICE_METADATA. If the metadata document does not specify the service element for the given service name, the service model will generate a service element with the corresponding WSDL ports for the service.

WS_SERVICE_METADATA_DOCUMENT document = {0};
WS_STRING documentName = WS_STRING_VALUE(L"a.wsdl");
document.name = &documentName;
document.content = &wsdlDocument
WS_SERVICE_METADATA_DOCUMENT** metadataDocuments [] = {&document};
WS_SERVICE_METADATA serviceMetadata = {0};
// Specify Metadata documents
serviceMetadata.count = WsCountOf(metadataDocuments);
serviceMetadata.documents = &metadataDocuments;
// Specify service name
serviceMetadata.serviceName = &serviceName;
serviceMetadata.serviceNs = &serviceNamespace;


WS_SERVICE_PROPERTY serviceProperties[1] = {0};
serviceProperties[0].id = WS_SERVICE_PROPERTY_METADATA;
serviceProperties[0].value =  &serviceMetadata;
serviceProperties[0].ValueSize = sizeof(serviceMetadata);

Note that no verification of the individual metadata documents will be performed on the documents. It is the responsiblity of the application to validate contents of the documents and ensure that all the imports paths are relatively specified.

The namespace specified is used to locate the document in which the service element will be added by the service host.

Addition of service element to the WSDL document

The service host provides facility for the application to add a service element on its behalf if one is not already specified. In order to enable this behavior an application must specify serivceName and serviceNs fields on the WS_SERVICE_METADATA structure. If serviceName and serviceNs are both NULL no service element is added to the WSDL document. Both these are used to identify document in which the serviceElement is going to be added.

If WS_SERVICE_PROPERTY_METADATA property is not specified no metadata exhange will take place on the service host.

Specifying the port on the WS_SERVICE_ENDPOINT

For a WS_SERVICE_ENDPOINT to be available as a port inside the service element in the WSDL document, the application must specify WS_SERVICE_ENDPOINT_PROPERTY_METADATA property on it.

WS_SERVICE_ENDPOINT_METADATA endpointPort = {0}
endpointPort.name = &portName;
endpointPort.bindingName = &bindingName;
endpointPort.bindingNs = &bindingNs;

WS_SERVICE_ENDPOINT_PROPERTY serviceProperties[1] = {0};
serviceProperties[0].id = WS_SERVICE_ENDPOINT_PROPERTY_METADATA;
serviceProperties[0].value =  &endpointPort;
serviceProperties[0].valueSize = sizeof(endpointPort);

It is assumed that the reference to the binding name and namespace exists in the documents specified on the service host as part of WS_SERVICE_PROPERTY_METADATA. The runtime does not verify this on behalf of the application.

Enable WS-MetadataExchange servicing on WS_SERVICE_ENDPOINT

In order to service WS-MetadataExchange requests,the service host must have at least one endpoint enabled for servicing WS-MetadataExchange requests. This is done by setting the appropriate version for WS-MetadataExchange on the WS_SERVICE_ENDPOINT.

WS_METADATA_EXCHANGE_TYPE metadataExchangeType = WS_METADATA_EXCHANGE_TYPE_MEX;
WS_SERVICE_ENDPOINT_PROPERTY serviceProperties[1] = {0};
serviceProperties[0].id = WS_SERVICE_ENDPOINT_PROPERTY_METADATA_EXCHANGE_TYPE;
serviceProperties[0].value =  &metadataExchangeType;
serviceProperties[0].ValueSize = sizeof(metadataExchangeType);

Enable HTTP GET servicing on WS_SERVICE_ENDPOINT

In order to serviceHTTP GET requests, the service host must have at least one endpoint enabled for servicing WS-MetadataExchange requests. This is done by setting the appropriate version for WS-MetadataExchange on the WS_SERVICE_ENDPOINT.

WS_METADATA_EXCHANGE_TYPE metadataExchangeType = WS_METADATA_EXCHANGE_TYPE_HTTP_GET;
WS_SERVICE_ENDPOINT_PROPERTY serviceProperties[1] = {0};
serviceProperties[0].id = WS_SERVICE_ENDPOINT_PROPERTY_METADATA_EXCHANGE_TYPE;
serviceProperties[0].value =  &metadataExchangeType;
serviceProperties[0].ValueSize = sizeof(metadataExchangeType);

Specifying URL suffix for Ws-MetadataExchange requests

An application can optionally enable only accepting requests for WS-MetadataExchange on a specific path. This is done by specifying a suffix for the given WS_SERVICE_ENDPOINT. This suffix is concatenated as-is to the actual URL for the WS_SERVICE_ENDPOINT. The concatenated string is used as the matching URL to the 'to' header received.

const WS_STRING suffix = WS_STRING_VALUE(L"mex");
WS_SERVICE_ENDPOINT_PROPERTY serviceProperties[1] = {};
serviceProperties[0].id = WS_SERVICE_ENDPOINT_PROPERTY_METADATA_EXCHANGE_URL_SUFFIX;
serviceProperties[0].value =  &suffix;
serviceProperties[0].valueSize = sizeof(suffix);

The following API elements relate to service metada.

Enumeration Description
WS_METADATA_EXCHANGE_TYPE Enables or disables WS-MetadataExchange and HTTP GET servicing on the endpoint.

 

Structure Description
WS_SERVICE_ENDPOINT_METADATA Represents the port element for the endpoint.
WS_SERVICE_METADATA Specifies the service metadata documents array.
WS_SERVICE_METADATA_DOCUMENT Specifies the individual documents that make up the service metadata.