Lokad Code DSL (homepage) is shared as open source project by Lokad in hopes that it would benefit the community.
You can get download binary from github downloads.
Lokad Contracts DSL is an optional console utility that you can run in the background. It tracks changes to files with special compact syntax and updates CS file. Changes are immediate upon saving file (and ReSharper immediately picks them). This is an improved version of Lokad Code DSL, it supports identities and can auto-generate interfaces for aggregates and aggregate state classes.
Lokad Code DSL is used by Lokad.CQRS (was originally part of it) and is explained in greater detail in BeingTheWorst Podcast - Episode 12.
You can try this out by starting Sample project and then changing Sample\Contracts.ddd (view [Contracts.ddd source] (http://github.com/Lokad/lokad-codedsl/blob/master/Sample/Contracts.ddd)). Code DSL tool will be regenerating corresponding contracts file as you change and save (view Contracts.cs source).
Current DSL code generates contracts classes that are compatible with DataContracts, ServiceStack.JSON and ProtoBuf.
Add namespace for our messages
namespace NameSpace
Result:
namespace NameSpace
{
...
}
extern "Lokad"
Result:
[DataContract(Namespace = "Lokad")]
Universe(UniverseId Id, string name)
Result:
[DataContract(Namespace = "Lokad")]
public partial class Universe
{
[DataMember(Order = 1)] public UniverseId Id { get; private set; }
[DataMember(Order = 2)] public string Name { get; private set; }
Universe () {}
public Universe (UniverseId id, string name)
{
Id = id;
Name = name;
}
}
In order to use interface in contract classes, need to create interface shortcut first, definition of interface IIdentity must be contained in C# file
if ! = IIdentity
For the next step define simple class with one property
UniverseId!(long id)
Result:
[DataContract(Namespace = "Lokad")]
public partial class UniverseId : IIdentity
{
[DataMember(Order = 1)] public long Id { get; private set; }
UniverseId () {}
public UniverseId (long id)
{
Id = id;
}
}
Method arguments constants allow us to define constant to replace method argument definition. For example, now we can use term dateUtc instead full definition with argument type and name.
const dateUtc = DateTime dateUtc
Definition of application service must begining with interface key.
interface Universe(UniverseId Id)
{
// define shortcut for commands
if ? = IUniverseCommand
// define shortcut for events
if ! = IUniverseEvent<UniverseId>
CreateUniverse?(name)
// override ToString() for command
explicit "Create universe - {name}"
UniverseCreated!(name)
// override ToString() for event
explicit "Universe {name} created"
}
Result:
public interface IUniverseApplicationService
{
void When(CreateUniverse c);
}
public interface IUniverseState
{
void When(UniverseCreated e);
}
Command and corresponding event
[DataContract(Namespace = "Lokad")]
public partial class CreateUniverse : IUniverseCommand
{
[DataMember(Order = 1)] public UniverseId Id { get; private set; }
[DataMember(Order = 2)] public string Name { get; private set; }
CreateUniverse () {}
public CreateUniverse (UniverseId id, string name)
{
Id = id;
Name = name;
}
public override string ToString()
{
return string.Format(@"Create universe - {0}", Name);
}
}
[DataContract(Namespace = "Lokad")]
public partial class UniverseCreated : IUniverseEvent<UniverseId>
{
[DataMember(Order = 1)] public UniverseId Id { get; private set; }
[DataMember(Order = 2)] public string Name { get; private set; }
UniverseCreated () {}
public UniverseCreated (UniverseId id, string name)
{
Id = id;
Name = name;
}
public override string ToString()
{
return string.Format(@"Universe {0} created", Name);
}
}
| Sublime Text 2 | Visual Studio 2010 |
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Visual Studio 2010 settings
![Visual Studio settings] (https://github.com/Lokad/lokad-codedsl/raw/master/Docs/vs2010_settings.PNG)
[Improved DSL Syntax for DDD and Event Sourcing] (http://abdullin.com/journal/2012/7/25/improved-dsl-syntax-for-ddd-and-event-sourcing.html)
Please, feel free to drop feedback in the Lokad Community.