HeadRest

A REST based headless approach for Umbraco.

HeadRest converts your Umbraco front end into a REST API by passing ModelsBuilder models through a mapping function to create serializable ViewModels and returning them as JSON payloads.

Out of the box HeadRest is configured to use UmbracoMapper to perform it's mappings, however you can define your own custom mapper function to use other model mappers such as AutoMapper.

Installation

Nuget

PM> Install-Package Our.Umbraco.HeadRest

Configuration

In order to configure HeadRest you will first of all need to create an Umbraco composer + compontent combination, resolving the HeadRest service from the DI container like so:

    public class HeadRestConfigComponent : IComponent
    {
        private readonly HeadRest _headRest;

        public HeadRestConfigComponent(HeadRest headRest) 
            => _headRest = headRest;

        public void Initialize()
        {
            // Configuration goes here
        }

        public void Terminate() { }
    }

    public class HeadRestConfigComposer : ComponentComposer<HeadRestConfigComponent>
    { }

From within the Initialize method, you can then configure your endpoint(s) via the ConfigureEndpoint method on the resolved HeadRest service instance:

    ...
    _headRest.ConfigureEndpoint(...);
    ...

Basic Configuration

For the most basic implementation, the following minimal configuration is all that is needed:

    _headRest.ConfigureEndpoint(new HeadRestOptions {
        ViewModelMappings = new HeadRestViewModelMap()
            .For(HomePage.ModelTypeAlias).MapTo<HomePageViewModel>()
            ...
    });

This will create an API endpoint at the path /, and will be anchored to the first content at the root of the site. It will use the list of ViewModelMappings provided to lookup the viewmodel to map a given node to.

Advanced Configuration

For a more advanced implementation, the following configuration shows all the supported options.

    _headRest.ConfigureEndpoint("/api/", "/root//nodeTypeAlias[1]", new HeadRestOptions {
        Mode = HeadRestEndpointMode.Dedicated,
        ControllerType = typeof(HeadRestController),
        Mapper = ctx => AutoMapper.Map(ctx.Content, ctx.ContentType, ctx.ViewModelType),
        ViewModelMappings = new HeadRestViewModelMap()
            .For(HomePage.ModelTypeAlias)
                .If(x => x.Request.HeadRestRouteParam("altRoute") == "init")
                .MapTo<InitViewModel>()
            .For(HomePage.ModelTypeAlias).MapTo<HomePageViewModel>()
            .Default().MapTo<BasicViewModel>(),
        CustomRouteMappings = new HeadRestRouteMap()
            .For("/(?<altRoute>init)/?$").MapTo("/")
    });

This will create an endpoint at the url /api/, and will be anchored to the node at the XPath /root//nodeTypeAlias[1]. In addition, the supplied controller will be used to handle the HeadRest requests and the supplied mapper function will be used to perform the mapping. It will use the list of ViewModelMappings provided to lookup the viewmodel to map a given node to. Lastly, a custom route is defined to map the url/api/init/ to the /api/ URL, storing the string "init", captured via the route pattern, which is then used in the ViewModelMappings to map /api/init/ request to the InitViewModel instead of the default HomePageViewModel.

Configuration Options

• basePath : string
  [optional, default:"/"]
  The base path from which your API will be accessible from.
• rootNodeXPath : string
  [optional, default:"/root/*[@isDoc][1]"]
  The XPath statement for the root node from which to anchor your API endpoint to.
• Mode : HeadRestEndpointMode
  [optional, default:HeadRestEndpointMode.Dedicated]
  The mode in which the headrest endpoint will run. Can be either HeadRestEndpointMode.Dedicated, in which case the generated endpoint URLs will be the primary URLs for the relevant content nodes, or HeadRestEndpointMode.Mixed, in which case node will maintain their primary URLs and the endpoint URLs will be added to the nodes "Other URLs" collection.
• ControllerType : Type
  [optional, default:typeof(HeadRestController)]
  The Controller to use to service the API requests. Controllers must inherit from HeadRestController. Useful to add extra FilterAttributes to the request such as AuthU and the OAuth attribute.
• Mapper : Func<HeadRestMapperContext, object>
  [optional, default:ctx => UmbracoMapper.Map(ctx.Content)]
  A function to perform the map between the nodes ModelsBuilder model and it's associated ViewModel. Defaults to using the build in UmbracoMapper.
• ViewModelMappings : HeadRestViewModelMap
  [required, default:null]
  A fluent list of mappings to determine which ViewModel a given content type should be mapped to. Multiple mappings can be defined for the same content type by defining a condition for the mapping via the flient .If(...) interface. Any conditional mappings should be defined before any non-conditional (fallback) mappings. You can set a default map that will be used if no other matching maps are found by using the .ForEverythingElse().MapTo<Type>() syntax. If a default map is defined, it must be the last map defined.
• CustomRouteMappings : HeadRestRouteMap
  [optional, default:null]
  A fluent list of custom route mappings to map any custom routes to a standard built in route. Routes are defined as regex patterns with any captured paramters being made accessible via a HeadRestRouteParam extension on the standard Request object. Usefull to support multiple routes pointing to the same endpoint URL, or for things like pagination URLs.

NB Whilst the ViewModelMappings tells HeadRest which ViewModel to map a content model to, it does not tell it how to actually map the properties over. For this you will need to instruct the model mapper using it's predefined mapping approach, for example, with UmbracoMapper you will want to define your mappings via a MapDefinition class registered via a composer like so:

    public class MyHeadRestMapDefinition : IMapDefinition
    {
        public void DefineMaps(UmbracoMapper mapper)
        {
            mapper.Define<FromType, ToType>(
                (frm, ctx) => ...,      // Constructor function
                (frm, to, ctx) => ...   // Map function
        }
    }
    
    public class MyHeadRestMapDefinisionComposer : IUserComposer
    {
        public void Compose(Composition composition)
        {
            composition.WithCollectionBuilder<MapDefinitionCollectionBuilder>()
                .Add<MyHeadRestMapDefinition>();
        }
    }

How is HeadRest different to Umbraco Headless?

	HeadRest	Umbraco Headless
Configuration	HeadRest requires configuring via a code based API so requires C# knowledge	Zero config required
Maintenance	You are responsible for applying security patches / updates	Automatic updates
Scalability	You are responsible for making the API scalable for your needs	Automatic scalability
API	Fixed API based on compiled ViewModels	Flexible query language
Security	You are responsible for securing your API (Suggest AuthU)	Security baked in
Back office UI	Potentially unused features visible	Unused features disabled
Supports use of 3rd party packages	Yes	No
Supports mixed install	Yes. You can have a headless API + website in one install	No. Headless only install
Supports custom backend code	Yes	No
Client libraries available	None. Roll your own	.NET Framework, .NET Core, Node.js
Hosting	Installs to any Umbraco version (7.12+)	Umbraco Cloud service only
Support	Limited community support	HQ Supported

Contributing To This Project

Anyone and everyone is welcome to contribute. Please take a moment to review the guidelines for contributing.

• Bug reports
• Feature requests
• Pull requests

License

Copyright © 2019 Matt Brailsford, Outfield Digital Ltd

Licensed under the MIT License