/// <summary>
/// Modifies a projector that would be understandable by the columns mapping process.
/// </summary>
/// <param name="projector">Projector.</param>
/// <returns>A projector that can be used by the columns mapping process for discover the DataTable columns.</returns>
private LambdaExpression ShapeProjector(LambdaExpression projector)
{
// Rewrites an projection of the form p => p into a new projection
// that uses the new operator (explicit projection): p => new {p.UnitPrice, p.InStock}
var implicitProjectionRewritter = new ImplicitProjectionRewritter();
projector = (LambdaExpression)implicitProjectionRewritter.Rewrite(projector);
// Evaluates any subtree that do not reference the projector's parameter
var partialEvaluator = new PartialEvaluator();
projector = (LambdaExpression)partialEvaluator.Evaluate(projector);
// Evalatues any ColumnSettings object within the projection
var columnSettingsEvaluator = new ColumnSettingsEvaluator();
projector = (LambdaExpression)columnSettingsEvaluator.Evaluate(projector);
// Rewrites a projection of the form p => p.Member into a new projection
// that wraps the member access as a ColumnSettings
var memberAccessProjRewritter = new SingleMemberProjectionRewritter();
projector = (LambdaExpression)memberAccessProjRewritter.Rewrite(projector);
var projectionValidator = new ProjectionValidator();
projectionValidator.Validate(projector);
// Marks as column any subtree that's not a NewExpression
var columnExpressionsMapper = new ColumnExpressionMapper();
projector = (LambdaExpression)columnExpressionsMapper.Map(projector);
return(projector);
}
public EditProjectionCommand(MFGContext context, IMapper mapper, ProjectionValidator validator)
{
_context = context;
_mapper = mapper;
_validator = validator;
}
