/// <summary>
/// Ensures the automatic history.
/// </summary>
/// <param name="context">The context.</param>
public static void EnsureAutoHistory(this DbContext context)
{
// TODO: only record the changed properties.
var jsonSetting = new JsonSerializerSettings
{
ContractResolver = new EntityContractResolver(context),
};
var entries = context.ChangeTracker.Entries().Where(e => e.State != EntityState.Unchanged &&
e.State != EntityState.Detached &&
IncludeEntity(e)).ToList();
if (entries.Count == 0)
{
return;
}
foreach (var entry in entries)
{
var history = new AutoHistory
{
TypeName = entry.Entity.GetType().FullName,
};
switch (entry.State)
{
case EntityState.Added:
// REVIEW: what's the best way to do this?
history.SourceId = "0";
history.Kind = EntityState.Added;
history.AfterJson = JsonConvert.SerializeObject(entry.Entity, Formatting.Indented, jsonSetting);
break;
case EntityState.Deleted:
history.SourceId = entry.PrimaryKey();
history.Kind = EntityState.Deleted;
history.BeforeJson = JsonConvert.SerializeObject(entry.Entity, Formatting.Indented, jsonSetting);
break;
case EntityState.Modified:
history.SourceId = entry.PrimaryKey();
history.Kind = EntityState.Modified;
history.BeforeJson = JsonConvert.SerializeObject(entry.Original(), Formatting.Indented, jsonSetting);
history.AfterJson = JsonConvert.SerializeObject(entry.Entity, Formatting.Indented, jsonSetting);
break;
default:
continue;
}
context.Add(history);
}
}
internal static AutoHistory AutoHistory(this EntityEntry entry)
{
var history = new AutoHistory
{
TableName = entry.Metadata.Relational().TableName,
};
// Get the mapped properties for the entity type.
// (include shadow properties, not include navigations & references)
var properties = entry.Properties;
var json = new JObject();
switch (entry.State)
{
case EntityState.Added:
foreach (var prop in properties)
{
if (prop.Metadata.IsKey() || prop.Metadata.IsForeignKey())
{
continue;
}
json[prop.Metadata.Name] = prop.CurrentValue != null
? JToken.FromObject(prop.CurrentValue, _jsonerializer)
: JValue.CreateNull();
}
// REVIEW: what's the best way to set the RowId?
history.RowId = "0";
history.Kind = EntityState.Added;
history.Changed = json.ToString();
break;
case EntityState.Modified:
var bef = new JObject();
var aft = new JObject();
foreach (var prop in properties)
{
if (prop.IsModified)
{
bef[prop.Metadata.Name] = prop.OriginalValue != null
? JToken.FromObject(prop.OriginalValue, _jsonerializer)
: JValue.CreateNull();
aft[prop.Metadata.Name] = prop.CurrentValue != null
? JToken.FromObject(prop.CurrentValue, _jsonerializer)
: JValue.CreateNull();
}
}
json["before"] = bef;
json["after"] = aft;
history.RowId = entry.PrimaryKey();
history.Kind = EntityState.Modified;
history.Changed = json.ToString();
break;
case EntityState.Deleted:
foreach (var prop in properties)
{
json[prop.Metadata.Name] = prop.OriginalValue != null
? JToken.FromObject(prop.OriginalValue, _jsonerializer)
: JValue.CreateNull();
}
history.RowId = entry.PrimaryKey();
history.Kind = EntityState.Deleted;
history.Changed = json.ToString();
break;
case EntityState.Detached:
case EntityState.Unchanged:
default:
throw new NotSupportedException("AutoHistory only support Deleted and Modified entity.");
}
return(history);
}
