com.mapinfo.midev.xml.mws

Interface IMWSDataProviderHandler

public interface IMWSDataProviderHandler

Interface for reading and writing a data source from and to a Named Table definition in the Named Resource Repository. A Named Table definition in the in-process model is composed of an ITableDefinition and an IDataSourceDefinition. These are represented in the MWS schema by the <mxp:XDPDataSourceDefinition> and <mxp:XDPConnection> elements, respectively.

Reading a Named Table Definition from the Repository

Spatial Server reads the contents of the <mxp:ConnectionSet> first. Each implementor of this interface is 'asked' to read a connection (i.e. IDataSourceDefinition) from the <mxp:ConnectionSet>. If the XML can be read then a IDataSourceDefinition (via a Connection instance) is returned; or null if it does not understand the XML construct it was given.

Next, the contents of the <mxp:DataSourceDefinitionSet> is read. Each implementor of this interface is 'asked' (via IMWSDataProviderHandler.readDataSourceDefinition(com.mapinfo.midev.xml.read.IXmlReader, java.io.File, java.util.Map, com.mapinfo.midev.tabledepot.TableDepot) to read a data source definition from the <mxp:DataSourceDefinitionSet>. If an implementation understands the constructs therein they are read and a ITableDefinition (via a DataSourceDefinition) is returned. If not null should be returned. A java.util.Map of connection name to Connection is also provided in case it is needed by the ITableDefinition.

Writing a Named Table Definition from the Repository

Writing follows the same pattern as reading. First the IDataSourceDefinitions are written to the <mxp:ConnectionSet>. Each implementor of this interface is 'asked' via IMWSDataProviderHandler.writeConnection(com.mapinfo.midev.xml.write.IXmlWriter, Connection) to write a specified IDataSourceDefinition. If an implementation understands the IDataSourceDefinition it is given it writes it to the <mxp:ConnectionSet> else false should be returned.

After writing all the IDataSourceDefinitions to the <mxp:ConnectionSet> the ITableDefinitions are written to the <mxp:DataSourceDefinitionSet>. Each implementation of this interface is 'asked' via IMWSDataProviderHandler.writeDataSourceDefinition(com.mapinfo.midev.xml.write.IXmlWriter, DataSourceDefinition, java.io.File) to write the specified ITableDefinition. If the implementation understands the specified ITableDefinition it writes it as an <mxp:XDPDataSourceDefinition> and true is returned; else false is returned.

Using the Specified IXmlReader and IXmlWriter

The specified IXmlReader and IXmlWriter may be used in any way. Implementations of this interface are given a copy of the XML 'stream' so changes to the reader or writer does not affect the rest of the system.

Method Summary

Modifier and Type	Method and Description
Connection	readConnection(IXmlReader r) Returns a Connection if the implementation read the contents of the <mxp:XDPConnection> element; or null if not.
DataSourceDefinition	readDataSourceDefinition(IXmlReader xml, File workingDir, Map connections, TableDepot tableDepot) Returns a DataSourceDefinition or null if the implementation did not understand the contents of the <mxp:XDPDataSourceDefinition> element pointed to by the specified IXmlReader.
boolean	writeConnection(IXmlWriter w, Connection connection) Returns true if the implementation wrote the specified Connection as an <mxp:XDPConnection> to the specified IXmlWriter; false if not.
boolean	writeDataSourceDefinition(IXmlWriter w, DataSourceDefinition mwsDataSourceDefinition, File workingDir) Returns true if the implementation of this method understood how to write the specified DataSourceDefinition; false if not.

Method Detail

readDataSourceDefinition

DataSourceDefinition readDataSourceDefinition(IXmlReader xml,
                                              File workingDir,
                                              Map connections,
                                              TableDepot tableDepot)

Returns a DataSourceDefinition or null if the implementation did not understand the contents of the <mxp:XDPDataSourceDefinition> element pointed to by the specified IXmlReader.

Parameters:

xml - The IXmlReader that is pointing to the <mxp:XDPDataSourceDefinition>

workingDir - the current working directory. Usually used for data sources that support relative paths.

connections - a Map of <mxp:ConnectionName>s to Connections that were read from the <mxp:ConnectionSet>.

tableDepot - a collection of ITables that have already be read from the .

Returns:

a DataSourceDefinition or null if the implementation did not understand the contents of the <mxp:XDPDataSourceDefinition> element.

writeDataSourceDefinition

boolean writeDataSourceDefinition(IXmlWriter w,
                                  DataSourceDefinition mwsDataSourceDefinition,
                                  File workingDir)

Returns true if the implementation of this method understood how to write the specified DataSourceDefinition; false if not.

Parameters:

w - the IXmlWriter to use to write the desired XML elements to the Named Table definition.

mwsDataSourceDefinition - the DataSourceDefinition to write to the Named Table definition.

workingDir - the working directory. May be used to store relative paths but not recommended.

Returns:

true if the implementation of this method understood how to write the specified DataSourceDefinition; false if not.

readConnection

Connection readConnection(IXmlReader r)

Returns a Connection if the implementation read the contents of the <mxp:XDPConnection> element; or null if not.

Parameters:

r - The IXmlReader that is pointing to the <mxp:XDPConnection>.

Returns:

a Connection if the implementation understand and read the contents of the <mxp:XDPConnection> element; or null if not.

writeConnection

boolean writeConnection(IXmlWriter w,
                        Connection connection)

Returns true if the implementation wrote the specified Connection as an <mxp:XDPConnection> to the specified IXmlWriter; false if not.

Parameters:

w - the IXmlWriter to use to write the desired XML elements.

connection - The Connection to write.

Returns:

true if the implementation wrote the specified Connection as an <mxp:XDPConnection> to the specified IXmlWriter; false if not.