Building static sites becomes all the more powerful when you introduce
the concept of working with external data.
Let's say you just want a `yaml` or `json` file in your project
root that contains some information that you don't want to repeat everywhere
on your site, something like:
```
title: "Crossbow.io"
cssFile: "/css/main.css"
```
To use this data like this in your app, you have a couple of ways to achieve it.
First, in your main configuration, you can specify a `data` property like so:
```js
var site = crossbow.builder({
data: {
site: {
title: "Crossbow.io",
cssFile: "/css/main.css"
}
}
})
```
Now, across every page in your website you'll have access to the `site` variable -
this means you can easily use any of the values like so:
```hbs
\{{site.title}}
```
## Auto data-file include
Of course, the previous approach is fine for a couple of pieces of data,
but if you prefer to keep your data in a separate file, you can use the
auto-include features of Crossbow with some special syntax. So assuming
you have a `_config.yaml` file in the root of your project, you can
automatically pull that in by using the following:
```js
var site = crossbow.builder({
data: {
site: "file:_config.yaml"
}
})
```
... now you have access to the `site` variable just as before.
## Data blocks
You can also load data on the fly from within your templates. You use the
block-helper style syntax and provide at least two parameters `src` and `as`.
- `src` is the path to the file containing data.
- `as` is the name of the variable you use to access the data within the block.
```hbs
\{{#data src="config.yaml" as="config"}}
\{{/data}}
```