Leprechaun

Leprechaun is a universal, open API for code generation from Rainbow serialized or Sitecore serialized Sitecore templates. Leprechaun uses state-of-the-art Roslyn code generation technology instead of T4 templates for speedy generation that doesn't require Visual Studio.

Why should I use Leprechaun?

It's Really Flexible

Leprechaun uses C# Script files as templates. If you're familiar with C#, it's a breeze. Out of the box, a Synthesis script file is provided, but it can easily be adapted to generate templates Glass, Fortis, or more! The template is essentially a big StringBuilder that you can build out however you like and Leprechaun will fill in the rest.

It Can Be Run at Build-Time

Sick of trying to resolve merge conflicts in gigantic model files? You don't need to do that anymore with Leprechaun. The outputted model files don't have to be checked into source control at all!

Why not?

Leprechaun generates models based off of the yaml files outputted by Rainbow. Since these yaml files are on disk already, there's no need for Sitecore to be running or for Visual Studio to be open in order to generate the models. Without these dependencies, you can generate models as a pre-build step.

It's Helix-Friendly

Most everything in Leprechaun is config-based. The base Leprechaun.config (for Rainbow, for Sitecore Serialization) file contains everything needed for Leprechaun to get started for a single project. However, these configs can be extended and overridden. For each module you have, create a CodeGen.config file and have it extend another config.

For example, a module named Feature.Promo would contain a CodeGen.config file like this:

<configuration name="Feature.Promo" extends="Sample.Base">

</configuration>

For more information, read the comments in the Leprechaun.config file and check out this Kam Figy blog post (for Unicorn, but the technique is the same).

Getting Started

Ok, you're convinced. Now how do you set it up?

Installing Leprechaun

Leprechaun is available as a dotnet tool. You can install it locally to a project, or globally.

To install it globally:

Open a PowerShell window and execute the following command:

dotnet tool install --global --no-cache Leprechaun.Cli

Then close and reopen PowerShell

To install it locally:

If your project does not have the following file: .config\dotnet-tools.json, go to the root of your project directory and type

dotnet new tool-manifest
dotnet tool install --no-cache Leprechaun.Cli

Updating Leprechaun

If you have Leprechaun installed locally, open a PowerShell window at the root of your project and run:

dotnet tool update --no-cache Leprechaun.Cli

If you have installed Leprechaun globally, open a PowerShell window anywhere you'd like and run:

dotnet tool update --global --no-cache Leprechaun.Cli

Uninstalling Leprechaun

If you have Leprechaun installed locally, open a PowerShell window at the root of your project and run:

dotnet tool uninstall Leprechaun.Cli

If you have installed Leprechaun globally, open a PowerShell window anywhere you'd like and run:

dotnet tool uninstall --global Leprechaun.Cli

---

Initial Configuration

General Steps

1. Grab the version of Leprechaun.config associated with your version of Leprechaun from GitHub:
   • Leprechaun.config (for Rainbow)
   • Leprechaun.config (for Sitecore Serialization)
2. Place the Leprechaun.config file somewhere close to the source code. In Helix solutions, I would recommend src/.
3. Grab a script template. Some pre-configured ones can be found here (link).
4. Open up Leprechaun.config and update settings where applicable. Pay close attention to the following:
   1. <configurations import=".....">
      • This line is going to tell Leprechaun where to look for additional configurations, typically for modules. Wildcards accepted.
      • For Helix solutions with Rainbow: .\*\*\code\CodeGen.config should work.
      • For Helix Solutions with Sitecore Serialization: **\*.module.json should work.
   2. <configuration name="Sample.Base">
      • Recommend changing this to [SolutionName].Base
   3. <codeGenerator scripts="..." outputFile="...">
      • scripts are the script templates that will be used. Pre-configured ones can be downloaded from https://github.com/blipson89/Leprechaun/tree/main/src/Leprechaun.CodeGen.Roslyn/Scripts
      • outputFile - I recommend $(configDirectory)\$(layer)\$(module)\code\Templates.cs for Habitat
        • For Helix solutions using NuGet: $(configDirectory)\..\..\..\$(layer)\$(module)\code\Models\Synthesis.Model.cs should work. This is assuming you leave the .exe in the packages folder.
   4. <templatePredicate rootNamespace="Sample.$(layer).$(module)">
      • Replace Sample with the appropriate namespace
      • Make sure that the <include> matches the path your data templates. (see Troubleshooting)

Rainbow-Specific Configuration Steps

After following the General Steps:

1. Open up Leprechaun.config and update Rainbow-specific settings where applicable. Pay close attention to the following:
   1. <dataStore physicalRootPath="...">
      • folder where Rainbow YAML files are.
      • For Helix solutions: $(configDirectory)\$(layer)\$(module)\serialization should work
        • For Helix solutions using NuGet: $(configDirectory)\..\..\..\$(layer)\$(module)\serialization
   2. <rainbowSettings type="Leprechaun.Console.LeprechaunRainbowSettings, Leprechaun.Console" ... />
      • If you altered the path lengths in your Unicorn configuration, you will need to adjust them here as the comment mentions

Sitecore-Specific Configuration Steps

After following the General Steps:

1. Open up Leprechaun.config and update Rainbow-specific settings where applicable. Pay close attention to the following:
   1. <moduleConfigReader type="..." configRootDirectory="..." singleInstance="true" />
      • the configRootDirectory should be the path to your project's sitecore.json file

Note: Leprechaun.config is NOT a file that gets deployed to the web server. It's purely used in build.

---

Module-Level Configuration

Now that the base configuration is setup, it's time to install the module-level configs. Create a config file in each module that contains a configuration name in the format Layer.Module and have it extend the base configuration (Step 2 from the Initial Configuration section).

Inside this config block, you can override any configurations from the main configuration file. The majority of the time, this won't be necessary.

Examples:

Unicorn:

<configuration name="Feature.Promo" extends="Sample.Base">

</configuration>

Sitecore Serialization

For Sitecore Serialization, rather than create a specific module file, you can add a leprechaun node do the .module.json file. The leprechaun node is a json representation of the xml in the Leprechaun.config file.

In the following example, the "items" section is setup by Sitecore and was only included as a point of reference.

Sample.module.json

{
  "namespace": "Feature.Sample",
  "items": {
    "includes": [
      {
        "name": "templates",
        "path": "/sitecore/templates/Feature/Sample"
      },
      {
        "name": "renderings",
        "path": "/sitecore/layout/Renderings/Feature/Sample"
      },
      {
        "name": "buttons",
        "database": "core",
        "path": "/sitecore/content/Applications/WebEdit/Custom Experience Buttons/Sample"
      }
    ]
  },
  "leprechaun": {
    "configuration": {
      "@extends": "Sample.Base",
      "@name": "Feature.Sample"
    },
  }
}

---

Integration

There are a few ways possible you can integrate Leprechaun.

NOTE: in all examples below, add the switch /r before the /c if you are using Rainbow

Example 1: Pre-Build Event in MSBuild

  <PropertyGroup>
    <PreBuildEvent>dotnet leprechaun /c $(SolutionDir)\src\Leprechaun.config</PreBuildEvent>
  </PropertyGroup>

Example 2: Create a gulp task from a custom install location

gulp.task('_Code-Generation', function (cb) {
    exec('dotnet leprechaun /c .\\src\\Leprechaun.config', function (err, stdout, stderr) {
        console.log(stdout);
        console.log(stderr);
        cb(err);
    });
})

Example 3: You can create a project target

<Target Name="Leprechaun">  
    <Exec Command="dotnet leprechaun /c $(SolutionDir)\src\Leprechaun.config"/>  
</Target>  

---

Watch

Leprechaun has the ability to watch the yaml files and automatically regenerate models when there's a change. Run Leprechaun with the /w switch to turn this on.

Watch is currently not supported for Sitecore serialization.

---

Migration from Synthesis Code Gen

If you are migrating from Synthesis Code Gen, have your models in source control, and Synthesis AutoRegenerate on non-local environments, you may want to note the following:

1. <templatePredicate rootNamespace="Sample.$(layer).$(module)">
   • You may want to use $(layer).$(module).Models if you used the default namespace.
2. You will no longer need your models in source control. You should remove them from source control and add them to your ignores (e.g. .gitignore or similar functionality)
3. You should disable Synthesis AutoRegenerate in non-local environments by removing it or transforming its event nodes out of the config in those environments.
   • Recommendation: disable Synthesis AutoRegenerate on local environments as well, and use Leprechaun's watch instead

---

Upgrading from Leprechaun 1.x

Updating your Leprechaun.config

The best way to upgrade your Leprechaun.config is to compare your file against the latest from the repo.

1. Add the following lines to your <shared> configuration:

   <orchestrator type="Leprechaun.Orchestrator, Leprechaun" singleInstance="true" />
   <inputProvider type="Leprechaun.InputProviders.Rainbow.RainbowInputProvider, Leprechaun.InputProviders.Rainbow" 
   singleInstance="true" />
   <watcher type="Leprechaun.InputProviders.Rainbow.RainbowWatcher, Leprechaun.InputProviders.Rainbow" singleInstance="true" />

2. Update namespaces for the following:
   1. Leprechaun.Console.ConsoleLogger, Leprechaun.Console becomes Leprechaun.Execution.ConsoleLogger, Leprechaun
   2. Leprechaun.Console.LeprechaunRainbowSettings, Leprechaun.Console becomes Leprechaun.InputProviders.Rainbow.Modules.RainbowSettingsModule, Leprechaun.InputProviders.Rainbow
   3. the <rainbowSettings> node has been renamed to <rainbowSettingsModule>
   4. Leprechaun.Filters.StandardTemplatePredicate, Leprechaun becomes Leprechaun.InputProviders.Rainbow.Filters.StandardTemplatePredicate, Leprechaun.InputProviders.Rainbow
   5. Leprechaun.TemplateReaders.DataStoreTemplateReader, Leprechaun becomes Leprechaun.InputProviders.Rainbow.TemplateReaders.DataStoreTemplateReader
   6. Leprechaun.Filters.RainbowNullFieldFilter, Leprechaun becomes Leprechaun.InputProviders.Rainbow.Filters.RainbowNullFieldFilter, Leprechaun.InputProviders.Rainbow

Updating your build process

1. Install the leprechaun.cli dotnet tool (see installation section above)
2. Update build scripts to add the /r switch before the /c if you are using Rainbow (i.e. dotnet leprechaun /r /c "path/to/config/file")

---

Troubleshooting

The model file is generated, but there are no templates in it!

The template predicate is probably not set correctly for your solution. In Leprechaun.config, take a peek at the <include> in this section:

<templatePredicate type="Leprechaun.Filters.StandardTemplatePredicate, Leprechaun" rootNamespace="$(layer).$(module)" singleInstance="true">
	<include name="Templates" path="/sitecore/templates/$(layer)/$(module)" />
</templatePredicate>