Bug 151694 appContext is null when evaluating parameters
On a report with parameters, during the resolution of the report parameters, datasource used to populate values of each parameters doesn't have any appContext. We used a jdbcbridbe, and thru appContext, we're retrieving jndi name and others parameters usueful for our datasource. In those case, during the evaluation of parameters, appContext is null so the datasource used to populate values of the parameters are not from the same database ...
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/GetParameterDefinitionTask.java
if ( DesignChoiceConstants.PARAM_TYPE_FLOAT.equals( valueType ) )
				return DataTypeUtil.toDouble( value );
		}
		catch ( BirtException e )
		{
			log.log( Level.SEVERE, e.getLocalizedMessage( ), e );
		}
		return value;
	}
	/**
	 * get selection choices from the data set.
	 * 
	 * @param dataSetName
	 *            data set name
	 * @param labelStmt
	 *            label statement
	 * @param valueStmt
	 *            value statement
	 * @param dataType
	 *            value type
	 * @return
	 */
	private Collection createDynamicSelectionChoices( String pattern, String dataSetName,
			String labelStmt, String valueStmt, String dataType, int limit,
			boolean fixedOrder )
	{
		ArrayList choices = new ArrayList( );
		ReportDesignHandle report = (ReportDesignHandle) this.runnable
				.getDesignHandle( );
		DataSetHandle dataSet = report.findDataSet( dataSetName );