/// <summary>
/// Register a property mapper as DbRef to serialize/deserialize only document reference _id
/// </summary>
internal static void RegisterDbRef(BsonMapper mapper, MemberMapper member, string collection)
{
member.IsDbRef = true;
if (member.IsList)
{
RegisterDbRefList(mapper, member, collection);
}
else
{
RegisterDbRefItem(mapper, member, collection);
}
}
/// <summary>
/// Register a property as a DbRef - implement a custom Serialize/Deserialize actions to convert entity to $id, $ref only
/// </summary>
private static void RegisterDbRefItem(BsonMapper mapper, MemberMapper member, string collection)
{
// get entity
var entity = mapper.GetEntityMapper(member.DataType);
member.Serialize = (obj, m) =>
{
// supports null values when "SerializeNullValues = true"
if (obj == null)
{
return(BsonValue.Null);
}
var idField = entity.Id;
// #768 if using DbRef with interface with no ID mapped
if (idField == null)
{
throw new LiteException("There is no _id field mapped in your type: " + member.DataType.FullName);
}
var id = idField.Getter(obj);
return(new BsonDocument
{
{ "$id", m.Serialize(id.GetType(), id, 0) },
{ "$ref", collection }
});
};
member.Deserialize = (bson, m) =>
{
var idRef = bson.AsDocument["$id"];
return(m.Deserialize(entity.ForType,
idRef.IsNull ?
bson : // if has no $id object was full loaded (via Include) - so deserialize using normal function
new BsonDocument {
{ "_id", idRef }
})); // if has $id, deserialize object using only _id object
};
}
/// <summary>
/// Register a property as a DbRefList - implement a custom Serialize/Deserialize actions to convert entity to $id, $ref only
/// </summary>
private static void RegisterDbRefList(BsonMapper mapper, MemberMapper member, string collection)
{
// get entity from list item type
var entity = mapper.GetEntityMapper(member.UnderlyingType);
member.Serialize = (list, m) =>
{
// supports null values when "SerializeNullValues = true"
if (list == null)
{
return(BsonValue.Null);
}
var result = new BsonArray();
var idField = entity.Id;
foreach (var item in (IEnumerable)list)
{
if (item == null)
{
continue;
}
var id = idField.Getter(item);
result.Add(new BsonDocument
{
{ "$id", m.Serialize(id.GetType(), id, 0) },
{ "$ref", collection }
});
}
return(result);
};
member.Deserialize = (bson, m) =>
{
var array = bson.AsArray;
if (array.Count == 0)
{
return(m.Deserialize(member.DataType, array));
}
// copy array changing $id to _id
var result = new BsonArray();
foreach (var item in array)
{
var refId = item.AsDocument["$id"];
// if refId is null was included by "include" query, so "item" is full filled document
if (refId.IsNull)
{
result.Add(item);
}
else
{
result.Add(new BsonDocument {
{ "_id", refId }
});
}
}
return(m.Deserialize(member.DataType, result));
};
}
/// <summary>
/// Use this method to override how your class can be, by default, mapped from entity to Bson document.
/// Returns an EntityMapper from each requested Type
/// </summary>
protected virtual EntityMapper BuildEntityMapper(Type type)
{
var mapper = new EntityMapper
{
Members = new List <MemberMapper>(),
ForType = type
};
var idAttr = typeof(BsonIdAttribute);
var ignoreAttr = typeof(BsonIgnoreAttribute);
var fieldAttr = typeof(BsonFieldAttribute);
var indexAttr = typeof(BsonIndexAttribute);
var dbrefAttr = typeof(BsonRefAttribute);
var members = GetTypeMembers(type);
var id = GetIdMember(members);
foreach (var memberInfo in members)
{
// checks [BsonIgnore]
if (memberInfo.IsDefined(ignoreAttr, true))
{
continue;
}
// checks field name conversion
var name = ResolveFieldName(memberInfo.Name);
// check if property has [BsonField]
var field = (BsonFieldAttribute)memberInfo.GetCustomAttributes(fieldAttr, false).FirstOrDefault();
// check if property has [BsonField] with a custom field name
if (field != null && field.Name != null)
{
name = field.Name;
}
// checks if memberInfo is id field
if (memberInfo == id)
{
name = "_id";
}
// test if field name is OK (avoid to check in all instances) - do not test internal classes, like DbRef
if (BsonDocument.IsValidFieldName(name) == false)
{
throw LiteException.InvalidFormat(memberInfo.Name);
}
// create getter/setter function
var getter = Reflection.CreateGenericGetter(type, memberInfo);
var setter = Reflection.CreateGenericSetter(type, memberInfo);
// check if property has [BsonId] to get with was setted AutoId = true
var autoId = (BsonIdAttribute)memberInfo.GetCustomAttributes(idAttr, false).FirstOrDefault();
// get data type
var dataType = memberInfo is PropertyInfo ?
(memberInfo as PropertyInfo).PropertyType :
(memberInfo as FieldInfo).FieldType;
// check if datatype is list/array
var isList = Reflection.IsList(dataType);
// create a property mapper
var member = new MemberMapper
{
AutoId = autoId == null ? true : autoId.AutoId,
FieldName = name,
MemberName = memberInfo.Name,
DataType = dataType,
IsList = isList,
UnderlyingType = isList ? Reflection.GetListItemType(dataType) : dataType,
Getter = getter,
Setter = setter
};
// check if property has [BsonRef]
var dbRef = (BsonRefAttribute)memberInfo.GetCustomAttributes(dbrefAttr, false).FirstOrDefault();
if (dbRef != null && memberInfo is PropertyInfo)
{
RegisterDbRef(this, member, dbRef.Collection ?? ResolveCollectionName((memberInfo as PropertyInfo).PropertyType));
}
// support callback to user modify member mapper
if (ResolveMember != null)
{
ResolveMember(type, memberInfo, member);
}
// test if has name and there is no duplicate field
if (member.FieldName != null && mapper.Members.Any(x => x.FieldName == name) == false)
{
mapper.Members.Add(member);
}
}
return(mapper);
}