Web Services Translator

The Web Services translator, known by the type name ws, exposes stored procedures for calling web services backed by a Teiid WS resource adapter. The WS resource adapter may optionally be configured to point at a specific WSDL.  Results from this translator will commonly be used with the TEXTTABLE or XMLTABLE table functions to use CSV or XML formated data.

Execution Properties

Name Description When Used Default

DefaultBinding

The binding that should be used if one is not specified. Can be one of HTTP, SOAP11, or SOAP12

invoke*

SOAP12

DefaultServiceMode

The default service mode. For SOAP, MESSAGE mode indicates that the request will contain the entire SOAP envelope and not just the contents of the SOAP body. Can be one of MESSAGE or PAYLOAD

invoke* or WSDL call

PAYLOAD

XMLParamName

Used with the HTTP binding (typically with the GET method) to indicate that the request document should be part of the query string.

invoke*

null - unused
Note
 Setting the proper binding value on the translator is recommended as it removes the need for callers to pass an explicit value. If your service is actually uses SOAP11, but the binding used SOAP12 you will receive execution failures.

There are no ws importer settings, but it can provide metadata for VDBs.  If the connection is configured to point at a specific WSDL, the translator will import all SOAP operations under the specified service and port as procedures.

Importer Properties

When specifying the importer property, it must be prefixed with "importer.". Example: importer.tableTypes

Name Description Default

importWSDL

Import the metadata from the WSDL URL configured in resource-adapter

true

Usage

The WS translator exposes low level procedures for accessing web services. See also the twitter example in the kit.

Invoke Procedure

Invoke allows for multiple binding, or protocol modes, including HTTP, SOAP11, and SOAP12.

Procedure invoke(binding in STRING, action in STRING, request in XML, endpoint in STRING, stream in BOOLEAN) returns XML

The binding may be one of null (to use the default) HTTP, SOAP11, or SOAP12. Action with a SOAP binding indicates the SOAPAction value. Action with a HTTP binding indicates the HTTP method (GET, POST, etc.), which defaults to POST.

A null value for the binding or endpoint will use the default value. The default endpoint is specified in the WS resource adapter configuration. The endpoint URL may be absolute or relative. If it’s relative then it will be combined with the default endpoint.

Since multiple parameters are not required to have values, it is often more clear to call the invoke procedure with named parameter syntax.

call invoke(binding=>'HTTP', action=>'GET')

The request XML should be a valid XML document or root element.

InvokeHTTP Procedure

invokeHttp can return the byte contents of an HTTP(S) call.

Procedure invokeHttp(action in STRING, request in OBJECT, endpoint in STRING, stream in BOOLEAN, contentType out STRING, headers in CLOB) returns BLOB

Action indicates the HTTP method (GET, POST, etc.), which defaults to POST.

A null value for endpoint will use the default value. The default endpoint is specified in the WS resource adapter configuration. The endpoint URL may be absolute or relative. If it’s relative then it will be combined with the default endpoint.

Since multiple parameters are not required to have values, it is often more clear to call the invoke procedure with named parameter syntax.

call invokeHttp(action=>'GET')

The request can be one of SQLXML, STRING, BLOB, or CLOB. The request will be sent as the POST payload in byte form. For STRING/CLOB values this will default to the UTF-8 encoding. To control the byte encoding, see the to_bytes function.

The optional headers parameter can be used to specify the request header values as a JSON value. The JSON value should be a JSON object with primitive or list of primitive values.

call invokeHttp(... headers=>jsonObject('application/json' as "Content-Type", jsonArray('gzip', 'deflate') as "Accept-Encoding"))

Recommendations for setting headers parameter:

  • Content-Type may be necessary if HTTP POST/PUT method is invoked

  • Accept is necessary if you want to control return Media Type

WSDL based Procedures

The procedures above give you anonymous way to execute any web service methods by supplying an endpoint, with this mechanism you can alter the endpoint defined in WSDL with a different endpoint. However, if you have access to the WSDL, then you can configure the WSDL URL in the web-service resource-adapter’s connection configuration, Web Service translator can parse the WSDL and provide the methods under configured port as pre-built procedures as its metadata. If you are using the default native metadata import, you will see the procedures in your web service’s source model.

Note
 Native queries - Native queries or a direct query execution procedure is not supported on the Web Services Translator.

Streaming Considerations

If the stream parameter is set to true, then the resulting lob value may only be used a single time. If stream is null or false, then the engine may need to save a copy of the result for repeated use. Care must be used as some operations, such as casting or XMLPARSE may perform validation which results in the stream being consumed.

JCA Resource Adapter

The resource adapter for this translator is a Web Service Data Source.

Note
 WS-Security - Currently you can only use WSDL based Procedures participate in WS-Security, when resource-adapter is configured with correct CXF configuration.

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