Radarr/Marr.Data/Mapping/MappingHelper.cs

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Data.Common;
namespace Marr.Data.Mapping
{
internal class MappingHelper
{
private MapRepository _repos;
private IDataMapper _db;
public MappingHelper(IDataMapper db)
{
_repos = MapRepository.Instance;
_db = db;
}
/// <summary>
/// Instantiates an entity and loads its mapped fields with the data from the reader.
/// </summary>
public object CreateAndLoadEntity<T>(ColumnMapCollection mappings, DbDataReader reader, bool useAltName)
{
return CreateAndLoadEntity(typeof(T), mappings, reader, useAltName);
}
/// <summary>
/// Instantiates an entity and loads its mapped fields with the data from the reader.
/// </summary>
/// <param name="entityType">The entity being created and loaded.</param>
/// <param name="mappings">The field mappings for the passed in entity.</param>
/// <param name="reader">The open data reader.</param>
/// <param name="useAltNames">Determines if the column AltName should be used.</param>
/// <returns>Returns an entity loaded with data.</returns>
public object CreateAndLoadEntity(Type entityType, ColumnMapCollection mappings, DbDataReader reader, bool useAltName)
{
// Create new entity
object ent = _repos.ReflectionStrategy.CreateInstance(entityType);
return LoadExistingEntity(mappings, reader, ent, useAltName);
}
public object LoadExistingEntity(ColumnMapCollection mappings, DbDataReader reader, object ent, bool useAltName)
{
// Populate entity fields from data reader
foreach (ColumnMap dataMap in mappings)
{
try
{
string colName = dataMap.ColumnInfo.GetColumName(useAltName);
int ordinal = reader.GetOrdinal(colName);
object dbValue = reader.GetValue(ordinal);
// Handle conversions
if (dataMap.Converter != null)
{
dbValue = dataMap.Converter.FromDB(dataMap, dbValue);
}
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if (dbValue != DBNull.Value && dbValue != null)
{
dataMap.Setter(ent, dbValue);
}
}
catch (Exception ex)
{
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string msg = string.Format("The DataMapper was unable to load the following field: '{0}'. {1}",
dataMap.ColumnInfo.Name, ex.Message);
throw new DataMappingException(msg, ex);
}
}
PrepareLazyLoadedProperties(ent);
return ent;
}
private void PrepareLazyLoadedProperties(object ent)
{
// Handle lazy loaded properties
Type entType = ent.GetType();
if (_repos.Relationships.ContainsKey(entType))
{
Func<IDataMapper> dbCreate = () =>
{
var db = new DataMapper(_db.ProviderFactory, _db.ConnectionString);
db.SqlMode = SqlModes.Text;
return db;
};
var relationships = _repos.Relationships[entType];
foreach (var rel in relationships.Where(r => r.IsLazyLoaded))
{
var lazyLoaded = (ILazyLoaded)rel.LazyLoaded.Clone();
lazyLoaded.Prepare(dbCreate, ent);
rel.Setter(ent, lazyLoaded);
}
}
}
public T LoadSimpleValueFromFirstColumn<T>(DbDataReader reader)
{
try
{
return (T)reader.GetValue(0);
}
catch (Exception ex)
{
string firstColumnName = reader.GetName(0);
string msg = string.Format("The DataMapper was unable to create a value of type '{0}' from the first column '{1}'.",
typeof(T).Name, firstColumnName);
throw new DataMappingException(msg, ex);
}
}
/// <summary>
/// Creates all parameters for a SP based on the mappings of the entity,
/// and assigns them values based on the field values of the entity.
/// </summary>
public void CreateParameters<T>(T entity, ColumnMapCollection columnMapCollection, bool isAutoQuery)
{
ColumnMapCollection mappings = columnMapCollection;
if (!isAutoQuery)
{
// Order columns (applies to Oracle and OleDb only)
mappings = columnMapCollection.OrderParameters(_db.Command);
}
foreach (ColumnMap columnMap in mappings)
{
if (columnMap.ColumnInfo.IsAutoIncrement)
continue;
var param = _db.Command.CreateParameter();
param.ParameterName = columnMap.ColumnInfo.Name;
param.Size = columnMap.ColumnInfo.Size;
param.Direction = columnMap.ColumnInfo.ParamDirection;
object val = columnMap.Getter(entity);
param.Value = val ?? DBNull.Value; // Convert nulls to DBNulls
if (columnMap.Converter != null)
{
param.Value = columnMap.Converter.ToDB(param.Value);
}
// Set the appropriate DbType property depending on the parameter type
// Note: the columnMap.DBType property was set when the ColumnMap was created
MapRepository.Instance.DbTypeBuilder.SetDbType(param, columnMap.DBType);
_db.Command.Parameters.Add(param);
}
}
/// <summary>
/// Assigns the SP result columns to the passed in 'mappings' fields.
/// </summary>
public void SetOutputValues<T>(T entity, IEnumerable<ColumnMap> mappings)
{
foreach (ColumnMap dataMap in mappings)
{
object output = _db.Command.Parameters[dataMap.ColumnInfo.Name].Value;
dataMap.Setter(entity, output);
}
}
/// <summary>
/// Assigns the passed in 'value' to the passed in 'mappings' fields.
/// </summary>
public void SetOutputValues<T>(T entity, IEnumerable<ColumnMap> mappings, object value)
{
foreach (ColumnMap dataMap in mappings)
{
dataMap.Setter(entity, Convert.ChangeType(value, dataMap.FieldType));
}
}
}
}