title: Attribute Lists Extension # Attribute Lists ## Summary The Attribute Lists extension adds a syntax to define attributes on the various HTML elements in markdown's output. This extension is included in the standard Markdown library. ## Syntax The basic syntax was inspired by [Maruku][]'s Attribute Lists feature. [Maruku]: http://maruku.rubyforge.org/proposal.html#attribute_lists ### The List An example attribute list might look like this: ```text {: #someid .someclass somekey='some value' } ``` A word which starts with a hash (`#`) will set the id of an element. A word which starts with a dot (`.`) will be added to the list of classes assigned to an element. A key/value pair (`somekey='some value'`) will assign that pair to the element. Be aware that while the dot syntax will add to a class, using key/value pairs will always override the previously defined attribute. Consider the following: ```text {: #id1 .class1 id=id2 class="class2 class3" .class4 } ``` The above example would result in the following attributes being defined: ```text id="id2" class="class2 class3 class4" ``` ### Block Level To define attributes for a block level element, the attribute list should be defined on the last line of the block by itself. ```text This is a paragraph. {: #an_id .a_class } ``` The above results in the following output: ```html

This is a paragraph.

``` The one exception is headers, as they are only ever allowed on one line. ```text A setext style header {: #setext} ================================= ### A hash style header ### {: #hash } ``` The above results in the following output: ```html

A setext style header

A hash style header

``` ### Inline To define attributes on inline elements, the attribute list should be defined immediately after the inline element with no white space. ```text [link](http://example.com){: class="foo bar" title="Some title!" } ``` The above results in the following output: ```html

link

``` ## Usage See [Extensions](index.md) for general extension usage, specify `markdown.extensions.attr_list` as the name of the extension. This extension does not accept any special configuration options.