Stardust.Paradox

Entity framework'ish tool for developing .net applications using gremlin graph query language with CosmosDb

Usage (asp.net core)

Startup.cs

ConfigureServices

Add the generated entity implementations to the IOC container (I will provide an extention method to make this easier)

 services.AddEntityBinding((entityType, entityImplementation) => services.AddTransient(entityType, entityImplementation))
        .AddScoped<MyEntityContext,MyEntityContext>()
        .AddScoped<IGremlinLanguageConnector>(s => new CosmosDbLanguageConnector(DbAccountName, AccessKey, "databaseName","collectionName"));

Defining the model

[VertexLabel("person")]
public interface IPerson : IVertex
{
    string Id {get;}

    string FirstName { get; set; }

    string LastName { get; set; }
    
    string Email { get; set; }

    EpochDateTime Birthday {get;set;}//Wrapper type for DateTime that serializes into unix epoch. Can be used in predicate steps directly.

    IEdgeCollection<IPerson> Parents { get; }

    IEdgeCollection<IPerson> Children { get; }

    IEdgeCollection<IPerson> Siblings { get; }

    [EdgeLabel("city")] //pointing to the Residents property in ICity
    IEdgeReference<ICity> HomeCity { get; }//use IEdgeReference to enable task-async operations

    IEdgeCollection<ICompany> Employers { get; }
}

[VertexLabel("city")]
public interface ICity : IVertex
{
    string Id { get; }

    string Name { get; set; }

    string ZipCode { get; set; }
    

   [ReverseEdgeLabel("city")] //pointing to the HomCity property in IPerson
    IEdgeCollection<Iperson> Residents { get; } //use IEdgeCollection to enable task-async operations on the collection

    IEdgeReference<ICountry> Country { get; }
}

[VertexLabel("company")]
public interface ICompany : IVertex
{
    string Id { get; }

    string Name { get; set; }

    IEdgeCollection<ICompany> Employees { get; }
}

[VertexLabel("country")]
public interface ICountry : IVertex
{
    string Id { get; }

    string Name { get; set; }

    string CountryCode { get; set; }

    string PhoneNoPrefix { get; set; }

    IEdgeCollection<ICity> Cities { get; }
}

 [EdgeLabel("employer")]
    public interface IEmployment : IEdge<IProfile, ICompany>
    {
        string Id { get; }

        EpochDateTime HiredDate { get; set; }

        string Manager { get; set; }
    }

Defining the entity context and generating the entity implementations

public class MyEntityContext : Stardust.Paradox.Data.GraphContextBase
{
    public IGraphSet<IPerson> Persons => GraphSet<IPerson>();

    public IGraphSet<ICity> Cities => GraphSet<ICity>();

    public IGraphSet<ICountry> Countries => GraphSet<ICountry>();

    public IGraphSet<ICompany> Companies => GraphSet<ICompany>();

    public IGraphSet<IEmployment> Employments => EdgeGraphSet<IEmployment>();

    public MyEntityContext(IGremlinLanguageConnector connector, IServiceProvider resolver) : base(connector, resolver)
    {
    }

    protected override bool InitializeModel(IGraphConfiguration configuration)
    {
        //Added some fluent configuration of the edges
        configuration.ConfigureCollection<IPerson>()
                .AddEdge(t => t.Children, "children").Reverse<IPerson>(t => t.Parents)
            .ConfigureCollection<ICity>()
            .ConfigureCollection<ICountry>()
                .AddEdge(t=>t.Cities).Reverse<ICountry>(t=>t.Country)
            .ConfigureCollection<ICompany>()
                .AddEdge(t => t.Employees, "employees").Reverse<IPerson>(t => t.Employers)
                .ConfigureCollection<IEmployment>();;
        return true;
    }
}

Using the datacontext

public class DemoController:Controller
{
    private MyEntityContext _dataContext;
    public DemoController(MyEntityContext dataContext)
    {
        _dataContext=dataContext;
    }

    public Task<IActionResult> GetDataAsync(string personId)
    {
        var person=await _dataContext.Persons.GetAsync(persionId);
        return new User
        {
            Id=person.Id,
            FirstName=person.FistName,
            LastName=person.LastName,
            Email=person.Email
        }
    }

    public Task<IActionResult> AddEmploymentAsync(string userId, string companyId,DateTime hiredDate, string managerName) //new in V2
    {
        var user=await await _dataContext.Persons.GetAsync(persionId);
        var company=await _dataContext.Companies.GetAsync(companyId);
        var e= _dataContext.Employments.Create(user,company);
        e.HiredDate=hiredDate.ToEpoch();
        e.ManagerName=managerName;
        await _dataContext.SaveChangesAsync();
        //alternative
        
    }

    public Task<IActionResult> AddEmploymentAlternativeAsync(string userId, string companyId,DateTime hiredDate, string managerName) //edge property handling in V1
    {
        var user=await await _dataContext.Persons.GetAsync(persionId);
        var company=await _dataContext.Companies.GetAsync(companyId);
        user.Employers.Add(company,new Dictionary<string,object>{
            {"hiredDate",hiredDate.ToEpoch()},
            {"managerName","managerName"}
        })
        await _dataContext.SaveChangesAsync();
        //alternative
        
    }
}