# Documentation Pages

Fractal makes it easy to create documentation for your project. Documentation pages are written in Github-flavoured Markdown (opens new window) and support the use of YAML 'front-matter' for configuration, as well as configuration via standard configuration files.

Additionally, if you need to generate more complex documentation, you can use a template language of your choosing (as for components, the default is Handlebars) to help dynamically generate pages.

Pages can be organised into as many folders and sub-folders as is necessary for your project, but must all reside in the documentation folder that you have configured in your project settings.

# A simple page

A very simple documentation page might look like this:

This is some documentation for the project. Still to do:

* Finish the docs
* Write tests
* Make the tea

Fractal will then take that and turn it into HTML ready for display:

<p>This is some documentation for the project. Still to do:</p>
    <li>Finish the docs</li>
    <li>Write tests</li>
    <li>Make the tea</li>

If there is no configuration data available (see below) then Fractal will generate metadata (such the title of the page) based on the file name.

# YAML front-matter

YAML 'front-matter' is a way of specifying configuration data at the top of a markdown file. It is a block of YAML that is fenced-off from the rest of the document via triple hyphen (---) separators. For example:

title: Change Log
This is the body of the page

In this case we are specifying that we want the title of the page (used in the web UI and other places) to be 'Change Log'. To see a full list of available configuration items, check out the documentation configuration reference.

If you don't want to use YAML front matter, you can also use a separate configuration file in the same way as you would for a component.

# Using data in page templates

Because pages are rendered using Handlebars (or another template engine of your choosing) before being run through the Markdown processor, you can easily dynamically generate sections of pages.

As for components, any context data that you wish to have access to in the page must be specified under the context property. You can then use Handlebars to generate content based on that data.

For instance, if you are using YAML front matter, you could re-create the example at the start of this page as follows:

title: Project Overview
    - Finish the docs
    - Write tests
    - Make the tea
This is some documentation for the project. Still to do:

{{#each items}}
* {{ this }}


It's important to note that the template engine rendering happens before the Markdown parsing, so you are free to use it to generate Markdown or HTML (which is ignored by Markdown parsers).

# Accessing page metadata

Pages only have direct access to data specified within the context object. If you need to access information about the page itself (such as the title) you have to use the special _self variable, as follows:

{{ _self.title }} <!-- Outputs: Project Overview -->

This is to prevent page configuration data clashing with context data intended to be used when rendering the page.

Note that the _self variable is actually a JSON representation of the page object itself, and not just a regurgitation of configuration data (i.e. title will have a value whether or not it is overridden in the configuration, as Fractal generates one for every page).

# Ordering pages

Pages can be ordered by prefixing file names with a two digit number (with leading zero, if required) followed by a hyphen. For example:

├── pages
│   ├── 01-index.md
│   ├── 02-changelog.md
│   └── 03-naming-conventions.md

Order prefixes are ignored when auto-generating page titles.

Alternatively, you can use the order property in the page's configuration file to specify an order without amending the filename.

# Hiding pages

Pages can be hidden from listings and navigation in two ways. You can either specify hidden: true in the pages's configuration file or you can prefix the page's filename with an underscore. So in the following example, the changelog page would not show up in any navigation:

├── pages
│   ├── _changelog.md
│   ├── index.md
│   └── naming-conventions.md


You can also combine ordering and hiding by constructing a filename such as _01-changelog.md.

# Escaping Handlebars expressions

Sometimes you may want to show a piece of code that itself contains a Handlebars expression, without that expression being parsed out at the rendering step. To do this you can prefix the expression with a backslash:

\{{ foo }}

This will prevent the Handlebars template engine from attempting to render that variable and will instead just keep it as a string.