# Overview

All the content that is rendered by the AIO application, and some of its configuration files, are generated from source files by [Dgeni](https://github.com/angular/dgeni).
Dgeni is a general purpose documentation generation tool.

Markdown files in `/aio/content`, code comments in the core Angular source files and example files are processed and transformed into files that are consumed by the AIO application.

Dgeni is configured by "packages", which contain services and processors.
Some of these packages are installed as `node_modules` from the [dgeni-packages](https://github.com/angular/dgeni-packages) and some are specific to the AIO project.

The project specific packages are stored in this folder (`aio/tools/transforms`).

If you are an author and want to know how to generate the documentation, the steps are outlined in the top level [README.md](../../README.md#guide-to-authoring).

## Root packages

To run Dgeni, you must specify a root package, which acts as the entry point to the documentation generation.
This root package, in turn requires a number of other packages, some are defined locally in the `tools/transforms` folder, such as `tools/transforms/cheatsheet-package` and `tools/transforms/content-package`, etc.
And some are brought in from the `dgeni-packages` node modules, such as `jsdoc` and `nunjucks`.

* The primary root package is defined in `tools/transforms/angular.io-package/index.js`.
  This package is used to run a full generation of all the documentation.
* There are also root packages defined in `tools/transforms/authors-package/*-package.js`.
  These packages are used by the documentation authors when writing docs, since it allows them to run partial doc generation, which is not complete but is faster for quickly seeing changes to the document that you are working on.

## Other packages

* angular-base-package
* angular-api-package
* angular-content-package
* content-package
* examples-package
* links-package
* post-process-package
* remark-package
* target-package

## Templates

All the templates for the angular.io dgeni transformations are stoted in the `tools/transforms/templates` folder.
See the [README](./templates/README.md).