Extends DocPad's tagging features by adding tag cloud generation and automatic tag index pages.

npm install --save docpad-plugin-tagging

Add tag metadata to your documents as described in the Related Plugin.

The plugin adds the @getTagCloud() template helper, which returns an object containing the tag cloud data of the form:

yellow:
	tag: "yellow"			// the tag name
	url: "/tags/yellow"		// URL of the tag index page
	count: 5					// number of documents containing the tag
	weight: 0.25				// weight of the tag
blue:
	tag: "blue"
	url: "/tags/blue"
	count: 3
	weight: 0.12
...

The following example iterates through the tag cloud and generates links to the tag index pages (in eco):

<% for tag, data of @getTagCloud(): %>
    <a href="<%= data.url %>" data-tag-count="<%= data.count %>" data-tag-weight="<%= data.weight %>">
        <%= tag %>
    </a>
<% end %>

Note that in this example we've added the count and weight here as HTML5 data fields so that a client-side script can apply the desired styling. You can of course do whatever you wish with the count or weight values, such as adding inline CSS for setting the font-size (but of course we don't do that kind of thing anymore right?)

The plugin will also dynamically generate a document for each tag found with the url tags/[tagname].html. The index documents are created with the following metadata (by default):

---
layout: tags
tag: [tagname]
---

The plugin does not generate any content for the index pages. You are in complete control of what is displayed on the index pages via the layout file.

For example, let's create the following file at layouts/tags.html.eco to display a list of all documents that have the tag in question:

---
layout: default
---
<h1>Pages tagged with '<%= @document.tag %>'</h1>

<ul>
<% for doc in @getCollection('documents').findAll({tags: '$in': @document.tag}).toJSON(): %>
    <li><a href="<%= doc.url %>"><%= doc.title %></a></li>
<% end %>
</ul>

The plugin also adds a @getTagUrl(tagname) template helper so you can easily get the URL of the index page for a particular tag. For example, in your templates you could display a list of the document's tags as links to their index page (this time in coffeekup just to keep life interesting):

---
title: "Random document"
layout: default
tags:
 - blarky
 - snargle
 - floopy
---
h2 -> "My Tags"
ul ->
    for tag in @document.tags
        li -> a href: @getTagUrl(tag), -> tag

• collectionName : Can be used to narrow the scope of the plugin to a specific collection and therefore improve performance (defaults to 'documents').
• indexPageLayout : Override the name of the layout file used for the tag index pages (defaults to 'tags').
• indexPagePath : Override the relative output path of the tag index pages (defaults to 'tags'). An Array of paths is also accepted (e.g. ['en/tags', 'de/tags'])
• getTagWeight : Override the function used to generate the tag weights (see below).

By default, the tag weights are calculated using a simple logarithmic algorithm. If that isn't floating your proverbial boat you are free to override this function with the weight function of your choosing. For example in your docpad config you could add:

plugins:
    tagging:
        getTagWeight: (count, maxCount) ->
            return count/maxCount

Here count is the number of occurences of the tag, and maxCount is the count of the tag with the highest number of occurrences.

Licensed under the incredibly permissive MIT License
Copyright © 2013 Richard Antecki