Codegen

This is simple code generator that uses Stencil as template language and as input you can provide a context using a YAML, JSON or PLIST file.

Codegen is helpful for the cases that you have to autogenerate code, but as input, you can't use your source code. For instance, you can have a YAML with a list of feature flags and from there, autogenerate all the related boilerplate code. Check Word of the Day example to learn more about that.

If you can use your source code as input to autogenerate the code, you should try Sourcery.

Stencil is a simple and powerful template language for Swift, you can find more information here.

Codegen also uses StencilSwiftKit, that library adds more Tags and Filters to Stencil.

Installation

• Building with Swift Package Manager:

You can clone the project and then run:

$ swift build -c release
$ cd .build/release
$ cp -f codegen /usr/local/bin/codegen

Alternatively, you can run $ sh install.sh from the root folder.

• Homebrew

🚧coming soon 🚧

Usage

Codegen is a command line tool. You have to provide three parameters:

• --input or -i A path to the file input.
• --template or -t A path to the stencil template.
• --output or -o A path for the autogenerated codoe.

$ codegen -i fruits.yaml -t template.stencil -o fruits.html

As input you can provide a YAML, JSON or PLIST file, the extension is used to know how to parse the file.

Alternatively, instead of a file, you can provide as input a dictionary.

$ codegen -i '{"fruits": ["Apple", "Organge", "Lemon"]}' -t template.stencil -o fruits.html

By default, existing autogenerated files are not overriden. If you you want to override files everytime that you run codegen, include --override flag.

File annotations

In case that you want to generate multiple files from one template or just set a custom name for the autogenerated file based on the input, you can use file annotations.

Imagine that you have an input YAML of people:

Having this input.yaml

people:
  - name: "Pablo"
    city: "Barcelona"
    profession: "Software Engineer"
  - name: "John"
    city: "New York"
    profession: "Graphic Designer"
  - name: "Akira"
    city: "Tokyo"
    profession: "Writer"

If you want to generate one output file for each person, you can create a template like:

{% for person in people %}
// codegen:file:begin:{{ person.name }}.md
{{ person.name }} is from {{ person.city }} and works as {{ person.profession }}.
// codegen:file:end
{% endfor %}

That will generate three files:

Pablo.md

Pablo is from Barcelona and works as a Software Engineer.

John.md

John is from New York and works as a Graphic Designer.

Akira.md

Akira is from Tokyo and works as a Writer.

Additionaly, you can define some directory as part of the file name:

// codegen:file:begin:{{ person.name }}/data.md

If the directory doesn't exist, it will be created.

You can also define a common root folder for all autogenerated annotated files when you execute the codegen command:

$ codegen -i people.yml -t template.stencil -o People

In that case, files will be generated with this directory structure:

People/Pablo/data.md
People/John/data.md
People/Akira/data.md