/// <summary>
/// Initializes a new instance of the DefaultQueryHandler class.
/// </summary>
/// <param name="sourcer">The query expression sourcer to use.</param>
/// <param name="authorizer">The query expression authorizer to use.</param>
/// <param name="expander">The query expression expander to use.</param>
/// <param name="processor">The query expression processor to use.</param>
public DefaultQueryHandler(IQueryExpressionSourcer sourcer,
IQueryExpressionAuthorizer authorizer = null,
IQueryExpressionExpander expander = null,
IQueryExpressionProcessor processor = null)
{
Ensure.NotNull(sourcer, nameof(sourcer));
this.authorizer = authorizer;
this.expander = expander;
this.processor = processor;
this.sourcer = sourcer;
}
public QueryExpressionVisitor(QueryContext context,
IQueryExpressionSourcer sourcer,
IQueryExpressionAuthorizer authorizer = null,
IQueryExpressionExpander expander = null,
IQueryExpressionProcessor processor = null)
{
Ensure.NotNull(sourcer, nameof(sourcer));
this.context = new QueryExpressionContext(context);
this.authorizer = authorizer;
this.expander = expander;
this.processor = processor;
this.sourcer = sourcer;
processedExpressions = new Dictionary <Expression, Expression>();
}
private Expression Source(Expression node)
{
if (this.sourcer == null)
{
this.sourcer = this.context.QueryContext
.GetHookPoint <IQueryExpressionSourcer>();
}
if (this.sourcer == null)
{
// Missing sourcer
throw new NotSupportedException();
}
node = this.sourcer.Source(this.context, this.BaseQuery != null);
if (node == null)
{
// Missing source expression
throw new NotSupportedException();
}
if (this.BaseQuery == null)
{
// The very first time the sourcer is used, the
// visited node represents the original starting
// point for the entire composed query, and thus
// it should produce a non-embedded expression.
var constant = node as ConstantExpression;
if (constant == null)
{
throw new NotSupportedException();
}
this.BaseQuery = constant.Value as IQueryable;
if (this.BaseQuery == null)
{
throw new NotSupportedException();
}
node = this.BaseQuery.Expression;
}
return(node);
}
private Expression Source(Expression node)
{
if (this.sourcer == null)
{
this.sourcer = this.context.QueryContext
.GetApiService <IQueryExpressionSourcer>();
}
if (this.sourcer == null)
{
// Missing sourcer
throw new NotSupportedException(Resources.QuerySourcerMissing);
}
node = this.sourcer.ReplaceQueryableSource(this.context, this.BaseQuery != null);
if (node == null)
{
// Missing source expression
throw new NotSupportedException(Resources.SourceExpressionMissing);
}
return(node);
}
private Expression Source(Expression node)
{
if (this.sourcer == null)
{
this.sourcer = this.context.QueryContext
.GetHookHandler<IQueryExpressionSourcer>();
}
if (this.sourcer == null)
{
// Missing sourcer
throw new NotSupportedException(Resources.QuerySourcerMissing);
}
node = this.sourcer.Source(this.context, this.BaseQuery != null);
if (node == null)
{
// Missing source expression
throw new NotSupportedException(Resources.SourceExpressionMissing);
}
if (this.BaseQuery == null)
{
// The very first time the sourcer is used, the
// visited node represents the original starting
// point for the entire composed query, and thus
// it should produce a non-embedded expression.
var constant = node as ConstantExpression;
if (constant == null)
{
throw new NotSupportedException(Resources.OriginalExpressionShouldBeConstant);
}
this.BaseQuery = constant.Value as IQueryable;
if (this.BaseQuery == null)
{
throw new NotSupportedException(Resources.OriginalExpressionShouldBeQueryable);
}
node = this.BaseQuery.Expression;
}
return node;
}
private Expression Source(Expression node)
{
if (this.sourcer == null)
{
this.sourcer = this.context.QueryContext
.GetApiService<IQueryExpressionSourcer>();
}
if (this.sourcer == null)
{
// Missing sourcer
throw new NotSupportedException(Resources.QuerySourcerMissing);
}
node = this.sourcer.ReplaceQueryableSource(this.context, this.BaseQuery != null);
if (node == null)
{
// Missing source expression
throw new NotSupportedException(Resources.SourceExpressionMissing);
}
return node;
}
