/// <summary>
/// Add the Fetch clauses to the query according to the given expand paths
/// </summary>
/// <param name="queryable">The query to expand</param>
/// <param name="expandsQueryString">Comma-separated list of properties to expand. May include nested paths of the form "Property/SubProperty"</param>
/// <param name="sessionFactory">Provides the NHibernate metadata for the classes</param>
/// <param name="expandMap">Will be populated with the names of the expanded properties for each type.</param>
/// <param name="expandCollections">If true, eagerly fetch collections. Caution: this causes problems with $skip and $top operations.
/// Default is false. expandMap will still be populated with the collection property, so it will be lazy loaded.
/// Be sure to set default_batch_fetch_size in the configuration for lazy loaded collections.</param>
/// <returns></returns>
public IQueryable ApplyExpansions(IQueryable queryable, string expandsQueryString, ExpandTypeMap expandMap, bool expandCollections = false)
{
string[] expandPaths = expandsQueryString.Split(',').Select(s => s.Trim()).ToArray();
if (!expandPaths.Any()) throw new Exception("Expansion Paths cannot be null");
if (queryable == null) throw new Exception("Query cannot be null");
return ApplyExpansions(queryable, expandPaths, expandMap, expandCollections);
}
/// <summary>
/// Recursively forces loading of each NHibernate proxy in the tree that matches an entry in the map.
/// </summary>
/// <param name="list">Top-level collection of objects</param>
/// <param name="expandMap">Properties to initialize for each type</param>
public static void InitializeList(IEnumerable list, ExpandTypeMap expandMap)
{
if (expandMap == null)
{
return;
}
var map = expandMap.map;
var depth = expandMap.maxDepth;
foreach (var el in list)
{
InitializeWithCascade(el, map, depth);
}
}
/// <summary>
/// Create an ExpandTypeMap populated according to the expandPaths.
/// </summary>
/// <param name="type">The type of the root element.</param>
/// <param name="expandPaths">The names of the properties to expand. May include nested paths of the form "Property/SubProperty"</param>
/// <param name="expandMap">Will be populated with the names of the expanded properties for each type. If null, a new one is created.</param>
/// <returns>expandMap</returns>
public static ExpandTypeMap MapExpansions(Type type, string[] expandPaths, ExpandTypeMap expandMap = null)
{
if (!expandPaths.Any())
{
throw new ArgumentException("Expansion Paths cannot be null");
}
if (expandMap == null)
{
expandMap = new ExpandTypeMap();
}
foreach (string expand in expandPaths)
{
// We always start with the resulting element type
var currentType = type;
// split on '/' or '.'
var segments = expand.Split('/', '.');
expandMap.Deepen(segments.Length);
foreach (string seg in segments)
{
if (expandMap != null && !expandMap.map.ContainsKey(currentType))
{
expandMap.map.Add(currentType, new List <string>());
}
// Gather information about the property
var propInfo = currentType.GetProperty(seg);
if (propInfo == null)
{
throw new ArgumentException("Type '" + currentType.Name + "' does not have property '" + seg + "'");
}
if (expandMap != null && !expandMap.map[currentType].Contains(seg))
{
expandMap.map[currentType].Add(seg);
}
var propType = propInfo.PropertyType;
currentType = propType;
}
}
return(expandMap);
}
/// <summary>
/// Add the Fetch clauses to the query according to the given expand paths
/// </summary>
/// <param name="queryable">The query to expand</param>
/// <param name="expandPaths">The names of the properties to expand. May include nested paths of the form "Property/SubProperty"</param>
/// <param name="sessionFactory">Provides the NHibernate metadata for the classes</param>
/// <param name="expandMap">Will be populated with the names of the expanded properties for each type.</param>
/// <param name="expandCollections">If true, eagerly fetch collections. Caution: this causes problems with $skip and $top operations.
/// Default is false. expandMap will still be populated with the collection property, so it will be lazy loaded.
/// Be sure to set default_batch_fetch_size in the configuration for lazy loaded collections.</param>
/// <returns></returns>
public IQueryable ApplyExpansions(IQueryable queryable, string[] expandPaths, ExpandTypeMap expandMap, bool expandCollections = false)
{
if (queryable == null)
{
throw new ArgumentException("Query cannot be null");
}
var nHibQuery = queryable.Provider as DefaultQueryProvider;
if (nHibQuery == null)
{
throw new ArgumentException("Expansion only supported on INHibernateQueryable queries");
}
if (!expandPaths.Any())
{
throw new ArgumentException("Expansion Paths cannot be null");
}
var currentQueryable = queryable;
foreach (string expand in expandPaths)
{
// We always start with the resulting element type
var currentType = currentQueryable.ElementType;
var isFirstFetch = true;
var isInvoking = true;
// split on '/' or '.'
var segments = expand.Split('/', '.');
expandMap.Deepen(segments.Length);
foreach (string seg in segments)
{
if (expandMap != null && !expandMap.map.ContainsKey(currentType))
{
expandMap.map.Add(currentType, new List <string>());
}
IClassMetadata metadata = sessionFactory.GetClassMetadata(currentType);
if (metadata == null)
{
throw new ArgumentException("Type '" + currentType + "' not recognized as a valid type for this Context");
}
// Gather information about the property
var propInfo = currentType.GetProperty(seg);
if (propInfo == null)
{
throw new ArgumentException("Type '" + currentType.Name + "' does not have property '" + seg + "'");
}
if (expandMap != null && !expandMap.map[currentType].Contains(seg))
{
expandMap.map[currentType].Add(seg);
}
var propType = propInfo.PropertyType;
var metaPropType = metadata.GetPropertyType(seg);
// When this is the first segment of a path, we have to use Fetch instead of ThenFetch
var propFetchFunctionName = (isFirstFetch ? "Fetch" : "ThenFetch");
// The delegateType is a type for the lambda creation to create the correct return value
System.Type delegateType;
if (metaPropType.IsCollectionType)
{
// We have to use "FetchMany" or "ThenFetchMany" when the target property is a collection
propFetchFunctionName += "Many";
// We only support IList<T> or something similar
propType = propType.GetGenericArguments().Single();
delegateType = typeof(Func <,>).MakeGenericType(currentType,
typeof(IEnumerable <>).MakeGenericType(propType));
if (!expandCollections)
{
// if we don't expand this collection, we won't invoke any sub-expansions of it either
// but we still need to traverse the tree top populate expandMap
isInvoking = false;
}
}
else
{
delegateType = typeof(Func <,>).MakeGenericType(currentType, propType);
}
if (isInvoking)
{
// Get the correct extension method (Fetch, FetchMany, ThenFetch, or ThenFetchMany)
var fetchMethodInfo = typeof(EagerFetchingExtensionMethods).GetMethod(propFetchFunctionName,
BindingFlags.Static |
BindingFlags.Public |
BindingFlags.InvokeMethod);
var fetchMethodTypes = new List <System.Type>();
fetchMethodTypes.AddRange(currentQueryable.GetType().GetGenericArguments().Take(isFirstFetch ? 1 : 2));
fetchMethodTypes.Add(propType);
fetchMethodInfo = fetchMethodInfo.MakeGenericMethod(fetchMethodTypes.ToArray());
// Create an expression of type new delegateType(x => x.{seg.Name})
var exprParam = System.Linq.Expressions.Expression.Parameter(currentType, "x");
var exprProp = System.Linq.Expressions.Expression.Property(exprParam, seg);
var exprLambda = System.Linq.Expressions.Expression.Lambda(delegateType, exprProp,
new System.Linq.Expressions.
ParameterExpression[] { exprParam });
// Call the *Fetch* function
var args = new object[] { currentQueryable, exprLambda };
currentQueryable = (IQueryable)fetchMethodInfo.Invoke(null, args) as IQueryable;
}
currentType = propType;
isFirstFetch = false;
}
}
return(currentQueryable);
}
/// <summary>
/// Add the Fetch clauses to the query according to the given expand paths
/// </summary>
/// <param name="queryable">The query to expand</param>
/// <param name="expandsQueryString">Comma-separated list of properties to expand. May include nested paths of the form "Property/SubProperty"</param>
/// <param name="sessionFactory">Provides the NHibernate metadata for the classes</param>
/// <param name="expandMap">Will be populated with the names of the expanded properties for each type.</param>
/// <param name="expandCollections">If true, eagerly fetch collections. Caution: this causes problems with $skip and $top operations.
/// Default is false. expandMap will still be populated with the collection property, so it will be lazy loaded.
/// Be sure to set default_batch_fetch_size in the configuration for lazy loaded collections.</param>
/// <returns></returns>
public IQueryable ApplyExpansions(IQueryable queryable, string expandsQueryString, ExpandTypeMap expandMap, bool expandCollections = false)
{
string[] expandPaths = expandsQueryString.Split(',').Select(s => s.Trim()).ToArray();
if (!expandPaths.Any())
{
throw new Exception("Expansion Paths cannot be null");
}
if (queryable == null)
{
throw new Exception("Query cannot be null");
}
return(ApplyExpansions(queryable, expandPaths, expandMap, expandCollections));
}
/// <summary>
/// Add the Fetch clauses to the query according to the given expand paths
/// </summary>
/// <param name="queryable">The query to expand</param>
/// <param name="expandPaths">The names of the properties to expand. May include nested paths of the form "Property/SubProperty"</param>
/// <param name="sessionFactory">Provides the NHibernate metadata for the classes</param>
/// <param name="expandMap">Will be populated with the names of the expanded properties for each type.</param>
/// <param name="expandCollections">If true, eagerly fetch collections. Caution: this causes problems with $skip and $top operations.
/// Default is false. expandMap will still be populated with the collection property, so it will be lazy loaded.
/// Be sure to set default_batch_fetch_size in the configuration for lazy loaded collections.</param>
/// <returns></returns>
public IQueryable ApplyExpansions(IQueryable queryable, string[] expandPaths, ExpandTypeMap expandMap, bool expandCollections = false)
{
if (queryable == null) throw new ArgumentException("Query cannot be null");
var nHibQuery = queryable.Provider as DefaultQueryProvider;
if (nHibQuery == null) throw new ArgumentException("Expansion only supported on INHibernateQueryable queries");
if (!expandPaths.Any()) throw new ArgumentException("Expansion Paths cannot be null");
var currentQueryable = queryable;
foreach (string expand in expandPaths)
{
// We always start with the resulting element type
var currentType = currentQueryable.ElementType;
var isFirstFetch = true;
var isInvoking = true;
// split on '/' or '.'
var segments = expand.Split('/', '.');
expandMap.Deepen(segments.Length);
foreach (string seg in segments)
{
if (expandMap != null && !expandMap.map.ContainsKey(currentType))
expandMap.map.Add(currentType, new List<string>());
IClassMetadata metadata = sessionFactory.GetClassMetadata(currentType);
if (metadata == null)
{
throw new ArgumentException("Type '" + currentType + "' not recognized as a valid type for this Context");
}
// Gather information about the property
var propInfo = currentType.GetProperty(seg);
if (propInfo == null)
{
throw new ArgumentException("Type '" + currentType.Name + "' does not have property '" + seg + "'");
}
if (expandMap != null && !expandMap.map[currentType].Contains(seg))
expandMap.map[currentType].Add(seg);
var propType = propInfo.PropertyType;
var metaPropType = metadata.GetPropertyType(seg);
// When this is the first segment of a path, we have to use Fetch instead of ThenFetch
var propFetchFunctionName = (isFirstFetch ? "Fetch" : "ThenFetch");
// The delegateType is a type for the lambda creation to create the correct return value
System.Type delegateType;
if (metaPropType.IsCollectionType)
{
// We have to use "FetchMany" or "ThenFetchMany" when the target property is a collection
propFetchFunctionName += "Many";
// We only support IList<T> or something similar
propType = propType.GetGenericArguments().Single();
delegateType = typeof(Func<,>).MakeGenericType(currentType,
typeof(IEnumerable<>).MakeGenericType(propType));
if (!expandCollections)
{
// if we don't expand this collection, we won't invoke any sub-expansions of it either
// but we still need to traverse the tree top populate expandMap
isInvoking = false;
}
}
else
{
delegateType = typeof(Func<,>).MakeGenericType(currentType, propType);
}
if (isInvoking)
{
// Get the correct extension method (Fetch, FetchMany, ThenFetch, or ThenFetchMany)
var fetchMethodInfo = typeof(EagerFetchingExtensionMethods).GetMethod(propFetchFunctionName,
BindingFlags.Static |
BindingFlags.Public |
BindingFlags.InvokeMethod);
var fetchMethodTypes = new List<System.Type>();
fetchMethodTypes.AddRange(currentQueryable.GetType().GetGenericArguments().Take(isFirstFetch ? 1 : 2));
fetchMethodTypes.Add(propType);
fetchMethodInfo = fetchMethodInfo.MakeGenericMethod(fetchMethodTypes.ToArray());
// Create an expression of type new delegateType(x => x.{seg.Name})
var exprParam = System.Linq.Expressions.Expression.Parameter(currentType, "x");
var exprProp = System.Linq.Expressions.Expression.Property(exprParam, seg);
var exprLambda = System.Linq.Expressions.Expression.Lambda(delegateType, exprProp,
new System.Linq.Expressions.
ParameterExpression[] { exprParam });
// Call the *Fetch* function
var args = new object[] { currentQueryable, exprLambda };
currentQueryable = (IQueryable)fetchMethodInfo.Invoke(null, args) as IQueryable;
}
currentType = propType;
isFirstFetch = false;
}
}
return currentQueryable;
}
/// <summary>
/// Create an ExpandTypeMap populated according to the expandPaths.
/// </summary>
/// <param name="type">The type of the root element.</param>
/// <param name="expandPaths">The names of the properties to expand. May include nested paths of the form "Property/SubProperty"</param>
/// <param name="expandMap">Will be populated with the names of the expanded properties for each type. If null, a new one is created.</param>
/// <returns>expandMap</returns>
public static ExpandTypeMap MapExpansions(Type type, string[] expandPaths, ExpandTypeMap expandMap = null)
{
if (!expandPaths.Any()) throw new ArgumentException("Expansion Paths cannot be null");
if (expandMap == null) expandMap = new ExpandTypeMap();
foreach (string expand in expandPaths)
{
// We always start with the resulting element type
var currentType = type;
// split on '/' or '.'
var segments = expand.Split('/','.');
expandMap.Deepen(segments.Length);
foreach (string seg in segments)
{
if (expandMap != null && !expandMap.map.ContainsKey(currentType))
expandMap.map.Add(currentType, new List<string>());
// Gather information about the property
var propInfo = currentType.GetProperty(seg);
if (propInfo == null)
{
throw new ArgumentException("Type '" + currentType.Name + "' does not have property '" + seg + "'");
}
if (expandMap != null && !expandMap.map[currentType].Contains(seg))
expandMap.map[currentType].Add(seg);
var propType = propInfo.PropertyType;
currentType = propType;
}
}
return expandMap;
}
