Entity Framework 6
Structr.EntityFramework package provides methods to easily implement auto-auditing in Entity Framework DbContext
, ModelBuilder
extensions which applies the entity type default configuration and IQueryable<T>
extensions to paginate through a list of entities.
Installation
EntityFramework package is available on NuGet.
dotnet add package Structr.EntityFramework
Usage
EntityFramework package have a reference to Structr.Domain package that provides some abstract classes for entities, value objects and interfaces which are intended to help to implement Domain Model.
Auto-auditing
Auto-auditing - it's entity change auditing for Entity Framework entities. The basic way to add auditing is to override the SaveChanges()
method of the DbContext
and plug in some logic for filling and tracking auditable properties (e.g. DateCreated
or CreatedBy
) automatically.
For example, create some entity that inherits Entity<TEntity,TKey>
class and ICreatable
interface.
public class Issue : Entity<Issue, int>, ICreatable
{
public string Name { get; set; }
public string Description { get; set; }
public DateTime DateCreated { get; set; } // It's an auditable property from "ICreatable".
}
Create your own DbContext
class implementation with configure some auditing dependencies (e.g. ITimestampProvider
) and override SaveChanges()
methods.
public class DataContext : DbContext
{
public DbSet<Issue> Issues { get; set; };
private readonly AuditTimestampProvider? _auditTimestampProvider;
public DataContext(string nameOrConnectionString, ITimestampProvider? timestampProvider = null)
: base(nameOrConnectionString)
{
_auditTimestampProvider = timestampProvider != null ? timestampProvider.GetTimestamp : null;
}
public override int SaveChanges(bool acceptAllChangesOnSuccess)
{
this.Audit(_auditTimestampProvider); // Auto-audit entities.
return base.SaveChanges(acceptAllChangesOnSuccess);
}
public override Task<int> SaveChangesAsync(bool acceptAllChangesOnSuccess, CancellationToken cancellationToken = default(CancellationToken))
{
this.Audit(_auditTimestampProvider); // Auto-audit entities.
return base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken);
}
}
Now if you add a new instance of Issue
to DbSet<Issue>
and call SaveChanges()
or SaveChangesAsync()
method, the DateCreated
property will be filled in automatically.
Auto-configure entity types
Create your own DbContext
class implementation and override OnModelCreating()
method with calling ApplyEntityConfiguration()
, ApplyValueObjectConfiguration()
and/or ApplyAuditableConfiguration()
methods.
public class DataContext : DbContext
{
public DataContext(string nameOrConnectionString)
: base(nameOrConnectionString)
{}
protected override void OnModelCreating(ModelBuilder builder)
{
builder.ApplyEntityConfiguration();
builder.ApplyValueObjectConfiguration();
builder.ApplyAuditableConfiguration();
}
}
ModelBuilder
extension methods list:
ApplyEntityConfiguration
Applies the default configuration for all classes inherited from the Entity<TEntity, TKey>
. Automatically configures PK for entities with HasKey()
method.
ApplyValueObjectConfiguration
Applies the default configuration for all classes inherited from the ValueObject<TValueObject>
.
ApplyAuditableConfiguration
Applies the default configuration for all classes that implement the IAuditable
.
You can configure options when applying entity types default configurations. For example, configure PK column name for all domain entities:
protected override void OnModelCreating(ModelBuilder builder)
{
builder.ApplyEntityConfiguration(options =>
{
options.Configure = (typeConfiguration) =>
{
typeConfiguration.Property("Id")
.HasColumnName($"{typeConfiguration.ClrType.Name}ID");
};
});
}
EntityConfigurationOptions
properties:
Configure
Action<IMutableEntityType, EntityTypeBuilder>
Delegate for configuring Entities. Default value is null
.
Configure name strategy for all properties of value objects:
protected override void OnModelCreating(ModelBuilder builder)
{
builder.ApplyValueObjectConfiguration(options =>
{
options.Configure = (typeConfiguration) =>
{
foreach (var property in typeConfiguration.ClrType.GetProperties(BindingFlags.Public | BindingFlags.Instance))
{
typeConfiguration.Property(property).HasColumnName(property.Name);
}
};
});
}
ValueObjectConfigurationOptions
properties:
Configure
Action<IMutableEntityType, string, OwnedNavigationBuilder>
Delegate for configuring Value Objects. Default value is null
.
Configure signed properties for auditable entities:
protected override void OnModelCreating(ModelBuilder builder)
{
builder.ApplyAuditableConfiguration(options =>
{
options.SignedColumnIsRequired = true;
options.SignedColumnMaxLength = 100;
});
}
AuditableConfigurationOptions
properties:
SignedColumnMaxLength
int
Defines the maximum size of a signed column (CreatedBy
, ModifiedBy
, DeletedBy
). Default value is 50
.
SignedColumnIsRequired
bool
Defines if a signed column (CreatedBy
, ModifiedBy
, DeletedBy
) is required. Default value is false
.
SoftDeletableFilterName
string
Defines the name of soft deletable filter. Default value is SoftDeletable
.
Pagination
Use .ToPagedList()
and .ToPagedListAsync()
extension methods for IQueryable<T>
to paginate result of entities query:
PagedList<Issue> issues = _dbContext.Issues
.OrderByDescending(x => x.DateCreated)
.ToPagedList(pageNumber: 1, pageSize: 10); // Returns only top 10 of latest issues.
If you call ToPagedList()
method with pageSize
parameter equals -1
that returns all entities from DbContext
without limitation.
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