JBake Permalink Implementation

[manikmagar]

jbake-org#294

This pull request implements Permalink/URI Generation and customization in JBake.

It is driven by a property permalink in jbake.properties file. Sample permalink pattern can be permalink=/:blog:/:title which will generate urls as blog\first-post.html.

If permalink is not specified then default pattern is /:filepath.

Every keyword should be separated with '/:'. It allows you to use any keywords from content header. eg. /:slug/:tags/:title.

Few Rules:

Some keywords are reserved for specific format. Below is the list of such keywords -

1. /:filepath: This keyword will result it addition of relative source file path from content folder. If you want to maintain the content folder structure in output then, permalink=/:filepath will result in generating URI structure same as source files.
2. /:filename: This keyword will result in addition of source file name (without extension).
3. /:YEAR, /:MONTH, :DAY: These keywords will add a related date part from content published date to url.
4. Adding Static words - Static words can be added in url by using ':' as suffix in permalink. For example, permalink=/:blog:/:filename will result in generation of urls like /blog/First-post.html

Using permalink in templates

Generated permalinks can be accessed in templates as content.permalink.

Extension-less permalinks

If ur.noExtension is set to true then all permalinks will be extension-less. For example, permalink=/:blog:/:filename will generate /blog/First-post/.

How to use different permalink patterns for each content type.

It is possible to use different permalink patterns based on content type. For example, post and page content type can use their own permalink patterns. permalink property will always be used as a default pattern for every content. To customize it based on content type, you can add another property permalink.{type} and specify pattern for it.

Sample configuration -
permalink=/:filepath
permalink.post=/:blog:/:filename
permalink.page=/:filename

Above configuration will result in pages with uri as filenames only, while posts will have suffix /blog/ for url. Any other content type will keep using /:filepath pattern.