Bug 131011 Support running query based on report document data
Data Engine should support running a query based on data set and expression data stored in a report document. This bugzilla entry serves as a repository for design docs and notes related to this feature.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/viewing/ExprMetaUtil.java
ExprMetaInfo exprMeta = new ExprMetaInfo( );
			exprMeta.setDataType( baseExpr.getDataType( ) );
			exprMeta.setGroupLevel( groupLevel );
			exprMeta.setName( exprName );
			
			if ( baseExpr instanceof IScriptExpression )
			{
				exprMeta.setType( ExprMetaInfo.SCRIPT_EXPRESSION );
				exprMeta.setJSText( ((IScriptExpression)baseExpr).getText( ) );
			}
			exprMetaList.add( exprMeta );
		}
	}
	
	/**
	 * @param inputStream
	 * @throws DataException
	 */
	public static ExprMetaInfo[] loadExprMetaInfo( InputStream inputStream )
			throws DataException
	{
		ExprMetaInfo[] exprMetas = null;
		DataInputStream dis = new DataInputStream( inputStream );
		try
		{
			int size = IOUtil.readInt( dis );
			exprMetas = new ExprMetaInfo[size + 2];
			for ( int i = 0; i < size; i++ )
			{
				exprMetas[i] = new ExprMetaInfo( );