# HeadLink
The HTML `` element is increasingly used for linking a variety of
resources for your site: stylesheets, feeds, favicons, trackbacks, and more. The
`HeadLink` helper provides a simple interface for creating and aggregating these
elements for later retrieval and output in your layout script.
The `HeadLink` helper has special methods for adding stylesheet links to its
stack:
- `appendStylesheet($href, $media = 'screen', $conditionalStylesheet = '', $extras = [])`
- `offsetSetStylesheet($index, $href, $media = 'screen', $conditionalStylesheet = '', $extras = [])`
- `prependStylesheet($href, $media = 'screen', $conditionalStylesheet = '', $extras = [])`
- `setStylesheet($href, $media = 'screen', $conditionalStylesheet = '', $extras = [])`
The `$media` value defaults to 'screen', but may be any valid media value.
`$conditionalStylesheet` is a string or boolean `false`, and will be used at
rendering time to determine if special comments should be included to prevent
loading of the stylesheet on certain platforms. `$extras` is an array of any
extra values that you want to be added to the tag.
Additionally, the `HeadLink` helper has special methods for adding 'alternate'
links to its stack:
- `appendAlternate($href, $type, $title, $extras = [])`
- `offsetSetAlternate($index, $href, $type, $title, $extras = [])`
- `prependAlternate($href, $type, $title, $extras = [])`
- `setAlternate($href, $type, $title, $extras = [])`
The `headLink()` helper method allows specifying all attributes necessary for a
`` element, and allows you to also specify placement: whether the
new element replaces all others, prepends (top of stack), or appends (end of
stack).
The `HeadLink` helper is a concrete implementation of the
[Placeholder helper](placeholder.md).
## Basic Usage
You may specify a `headLink` at any time. Typically, you will specify global
links in your layout script, and application specific links in your application
view scripts. In your layout script, in the `` section, you will then echo
the helper to output it.
```php
headLink(['rel' => 'icon', 'href' => '/img/favicon.ico'], 'PREPEND')
->appendStylesheet('/styles/basic.css')
->prependStylesheet(
'/styles/moz.css',
'screen',
true,
['id' => 'my_stylesheet']
);
// rendering the links from the layout:
echo $this->headLink();
?>
```
Output:
```html
```