/// <summary>
/// Produces the Linq expression representing the entire filter descriptors collection.
/// </summary>
/// <param name="filterDescriptors">Collection of filters</param>
/// <param name="filterOperator">The operator used to combine filters</param>
/// <param name="expressionCache">Cache for storing built expressions</param>
/// <returns>Produced linq expression, which can be <c>null</c> if there are no filter descriptors.</returns>
public static Expression BuildFiltersExpression(
FilterDescriptorCollection filterDescriptors,
FilterDescriptorLogicalOperator filterOperator,
ExpressionCache expressionCache)
{
Debug.Assert(filterDescriptors != null, "Unexpected null filterDescriptors");
Expression filtersExpression = null;
foreach (FilterDescriptor filterDescriptor in filterDescriptors)
{
// Ignored filters will not have a cache entry
if (expressionCache.ContainsKey(filterDescriptor))
{
Expression filterExpression = expressionCache[filterDescriptor];
if (filtersExpression == null)
{
filtersExpression = filterExpression;
}
else if (filterOperator == FilterDescriptorLogicalOperator.And)
{
filtersExpression = Expression.AndAlso(filtersExpression, filterExpression);
}
else
{
filtersExpression = Expression.OrElse(filtersExpression, filterExpression);
}
}
}
return(filtersExpression);
}
/// <summary>
/// Produces the Linq expression representing the entire filter descriptors collection.
/// </summary>
/// <param name="filterDescriptors">Collection of filters</param>
/// <param name="filterOperator">The operator used to combine filters</param>
/// <param name="expressionCache">Cache for storing built expressions</param>
/// <returns>Produced linq expression, which can be <c>null</c> if there are no filter descriptors.</returns>
public static Expression BuildFiltersExpression(
FilterDescriptorCollection filterDescriptors,
FilterDescriptorLogicalOperator filterOperator,
ExpressionCache expressionCache)
{
Debug.Assert(filterDescriptors != null, "Unexpected null filterDescriptors");
Expression filtersExpression = null;
foreach (FilterDescriptor filterDescriptor in filterDescriptors)
{
// Ignored filters will not have a cache entry
if (expressionCache.ContainsKey(filterDescriptor))
{
Expression filterExpression = expressionCache[filterDescriptor];
if (filtersExpression == null)
{
filtersExpression = filterExpression;
}
else if (filterOperator == FilterDescriptorLogicalOperator.And)
{
filtersExpression = Expression.AndAlso(filtersExpression, filterExpression);
}
else
{
filtersExpression = Expression.OrElse(filtersExpression, filterExpression);
}
}
}
return filtersExpression;
}
