ASF Pelican plugins

Note In 2019 Infra created ASF-Pelican as a structure and template for projects to use to build their websites, and for the ASF's own website.

In 2024, Infra moved from ASF-Pelican to the ASF Infrastructure Pelican Action GitHub Action to perform the same functions without being closely tied to BuildBot. The repository for this GHA is github.com/apache/infrastructure-actions/tree/main/pelican.

The following material is correct for both ASF-Pelican and its replacement.

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Plugins

You can find the available plugins for a site using the ASF-Pelican template in the themes/plugins folder of your website's project repository.

Plugin architecture

The plugins operate at various points in a Pelican build.

Pelican uses signals at various points.

Here is a high-level review of the sequence of events:

Pelican settings

Settings for a Pelican build are in your Pelican configuration file, pelicanconf.py. Here is where you list the plugins you are using.

PLUGIN_PATHS = ['./theme/plugins']
PLUGINS = ['asfgenid', 'asfdata', 'pelican-gfm', 'asfreader']

Initialization

At initialization, Pelican reads any ASF_DATA into a metadata dictionary that is available in every page in the site.

• The plugin .asfdata.py reads an .asfdata.yaml file and creates the metadata dictionary.

ASF_DATA_YAML = ".asfdata.yaml"
ASF_DATA = {
    'data': ASF_DATA_YAML,
    'metadata': { },
    'debug': True
}

• The asfgenid plugin ./asfgenid.py configures the site's features.

# Configure the asfgenid plugin
ASF_GENID = {
    'metadata': True,
    'elements': True,
    'headings': True,
    'headings_re': r'^h[1-4]',
    'permalinks': True,
    'toc': True,
    'toc_headers': r"h[1-4]",
    'tables': True,
    'debug': False
}

Readers (readers_init)

The system sets two important readers at this point. Readers are responsible for transforming page files to HTML and providing a metadata dictionary.

• GFMReader by the pelican-gfm plugin. This code is in a private repository - ask Infra. Transforms GitHub Flavored Markdown(GFM) to HTML.

• .md
• .markdown
• .mkd
• .mdown

• ASFReader,.asfreader.py) transforms an ezt template into GFM and then to HTML.

  • .ezmd

Content init (content_object_init)

This is signaled after a reader has processed the site's content. At this point plugins can review, record, and transform the HTML content.

• The asfgenid plugin, ./asfgenid.py, performs a number of steps. Some of the steps are optional.
  • Metadata transformation by looking up {{ key_expression }} in the page metadata.
  • Inventory of existing ID attributes.
  • Set ID and class attributes specified by {#id} and {.class} syntax.
  • Assign an ID to any headings without IDs.
  • Insert a table of contents if a [TOC] tag is present.

Apache CMS

Many projects had their websites served by the Apache CMS from 2010. It was deprecated in 2021. The CMS was written in Perl. We have a new approach that fits Pelican.

If you want to look into the old CMS process, its Subversion repository and history remain available.