gen-mdl is a code generator that takes a data model definition as input and produces code in C# and TypeScript for that model.
It's great at centralizing knowledge to keep data model classes in client side (browser) and server-side updated.
We attempt to follow DRY and KISS principles.
Our core principles
- Knowledge should be centered in a single place.
- You shouldn't have to look at files in different languages to understand your model.
- Data modeling should be simple.
- You should only provide as much detail as is actually needed, but rely on the defaults to do the rest.
- You write model definitions in YAML.
- You invoke gen-mdl with your model definition.
- You get code. :)
A model definition for a blog application looks like this.
%YAML 1.1
---
targets :
csharp :
path : Blog.Model\\Data
namespace : Blog.Model.Data
type_aliases :
id_t : int
typescript :
path : client\\app\\model
type_aliases :
id_t : int
enums :
blog_post_status : [draft, final]
entities :
author :
members:
id : id_t
name : string
alias : string
blog :
members:
id : id_t
title : string
posts :
type : blog_post
is_collection : true
author : author
blog_post :
members:
id : id_t
date_published : { type: datetime, is_nullable: true }
description : { type: string, is_nullable: true }
comments :
type : comment
is_collection : true
status : blog_post_status
comment :
members:
id : id_t
text : string
shared_in_fb : { type: bool, exclude: [typescript] }
For the model above you would get the following files
- Blog.Model\Data\Author.cs
namespace Blog.Model.Data
{
using System.ComponentModel.DataAnnotations;
public class Author
{
public int Id { get; set; }
[Required(AllowEmptyStrings = true)]
public string Name { get; set; }
[Required(AllowEmptyStrings = true)]
public string Alias { get; set; }
}
}- Blog.Model\Data\Blog.cs
namespace Blog.Model.Data
{
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
public class Blog
{
public int Id { get; set; }
[Required(AllowEmptyStrings = true)]
public string Title { get; set; }
[Required]
public IList<BlogPost> Posts { get; set; }
[Required]
public Author Author { get; set; }
}
}- Blog.Model\Data\BlogPost.cs
namespace Blog.Model.Data
{
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
public class BlogPost
{
public int Id { get; set; }
public DateTimeOffset? DatePublished { get; set; }
public string Description { get; set; }
[Required]
public IList<Comment> Comments { get; set; }
public BlogPostStatus Status { get; set; }
}
}- Blog.Model\Data\BlogPostStatus.cs
namespace Blog.Model.Data
{
public enum BlogPostStatus
{
Draft,
Final
}
}- Blog.Model\Data\Comment.cs
namespace Blog.Model.Data
{
using System.ComponentModel.DataAnnotations;
public class Comment
{
public int Id { get; set; }
[Required(AllowEmptyStrings = true)]
public string Text { get; set; }
public bool SharedInFb { get; set; }
}
}- client\app\model\author.ts
export default class Author {
id : number;
name : string;
alias : string;
}- client\app\model\blog-post-status.ts
enum BlogPostStatus {
Draft,
Final
}
export default BlogPostStatus;- client\app\model\blog-post.ts
import BlogPostStatus from './blog-post-status'
import Comment from './comment'
export default class BlogPost {
id : number;
datePublished : Date;
description : string;
comments : Comment[];
status : BlogPostStatus;
}- client\app\model\blog.ts
import BlogPost from './blog-post'
import Author from './author'
export default class Blog {
id : number;
title : string;
posts : BlogPost[];
author : Author;
}- client\app\model\comment.ts
export default class Comment {
id : number;
text : string;
}- client\app\model\index.ts
export * from './blog-post-status';
export * from './author';
export * from './blog';
export * from './blog-post';
export * from './comment';- .NET Framework 4 or higher.