Plugin Architecture

The plugins used operate at various points in a pelican build. Pelican uses signals at various points. These are documented here. At a high level consider the following sequence of events:

Pelican Settings

Settings for a Pelican Build are in your Pelican Configuration

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

Initialization

At this point any ASF_DATA is read into a metadata dictionary made available in every page.

• The asfdata plugin 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 configures its features.

ASF_GENID = {
    'metadata': True,
    'elements': True,
    'headings': True,
    'permalinks': True,
    'toc': True,
    'toc_headers': r"h[1-6]",
    'debug': False
}

Readers (readers_init)

Two important readers are set 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 by the asfreader plugin. Transforms an ezt template into GFM and then to HTML.

  • .ezmd

Content Init (content_object_init).

This is signaled after a Reader has processed content. At this point plugins can review, record, and transform the html content.

• The asfgenid plugin 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 and {.class} syntax.
  • Assign id to all headings without ids.
  • Insert a Table of Contents if a [TOC] tag is present.

Apache CMS

The Apache CMS was in perl. We have a new approach that fits Pelican. If you want to look into the CMS process the svn history remains available.