public static IList <IDataSource> WithFilters(
this IList <IDataSource> dataSources,
IMemberMapperData mapperData)
{
var dataSourceCount = dataSources.Count;
var filteredDataSources = new IDataSource[dataSourceCount];
for (var i = 0; i < dataSourceCount; ++i)
{
var dataSource = dataSources[i];
var filteredDataSource = filteredDataSources[i] = ApplyFilter(
dataSource.IsFallback ? dataSources[i - 1].SourceMember : dataSource.SourceMember,
dataSource,
mapperData);
if (!dataSource.IsFallback)
{
continue;
}
if (filteredDataSource != null)
{
break;
}
var filteredDataSourcesWithoutFallback = new IDataSource[dataSourceCount - 1];
filteredDataSourcesWithoutFallback.CopyFrom(filteredDataSources);
return(filteredDataSourcesWithoutFallback);
}
return(filteredDataSources);
}
private static bool TryAdjustToSingleUseableDataSource(
ref IList <IDataSource> dataSources,
IMemberMapperData mapperData)
{
var finalDataSource = dataSources.Last();
if (!finalDataSource.IsFallback)
{
return(false);
}
var finalValue = finalDataSource.Value;
if (finalValue.NodeType == ExpressionType.Coalesce)
{
// Coalesce between the existing target member value and the fallback:
dataSources[dataSources.Count - 1] = new AdHocDataSource(
finalDataSource.SourceMember,
((BinaryExpression)finalValue).Right,
finalDataSource.Condition,
finalDataSource.Variables);
return(false);
}
var targetMemberAccess = mapperData.GetTargetMemberAccess();
if (!ExpressionEvaluation.AreEqual(finalValue, targetMemberAccess))
{
return(false);
}
if (dataSources.Count == 2)
{
return(true);
}
var dataSourcesWithoutFallback = new IDataSource[dataSources.Count - 1];
dataSourcesWithoutFallback.CopyFrom(dataSources);
dataSources = dataSourcesWithoutFallback;
return(false);
}