Older blog entries for hugoduncan (starting at number 0)

27 Mar 2009 (updated 27 Mar 2009 at 23:56 UTC) »

I recently uploaded some links to my cl-blog-generator project, and have been getting some feedback with comparisons to other blog site generators, or compilers, such as Steve Kemp's Chronicle, or Jekyll as used on GitHub Pages. Compared to these, cl-blog-generator is immature, but takes a different approach in several areas that Charles Stewart suggested might be worth exploring. I look forward to any comments you might have.

Formatting

All the blog generators seem to use a file based approach for writing content, but they differ in the choice of input formats supported, and in the approach to templating. cl-blog-generator is the least flexible, requiring input in XHTML, while Chronicle allows HTML, Textile or Markdown, and Jekyll Textile or Markdown. For templates, Chronicle uses Perl's HTML::Template, and Jekyll uses Liquid. cl-blog-generator uses an approach which substitutes content into elements identified with specific id's or classes, similar to transforming the templates with XSLT.

cl-blog-generator's choice of XHTML input was driven by a requirement to enable the validation of post content in the editor, which is not possible using Chronicle's HTML input because of the headers and lack of a body or head element, and a desire to be able to use any CSS tricks I wanted, which ruled out Textile and Markdown, or any other markup language. The lack of an external templating engine in cl-blog-generator was driven by simplicity; I couldn't see a use for conditionals or loops given the fixed structure of the content, and this choice leads to templates that validate, unlike Jekyll, and which are not full of HTML comments. The current id and class naming scheme in cl-blog-generator could certainly use some refinement to improve the flexibility of the output content format, and I would definitely welcome requests for enhancements should the scheme not fit your requirements.

Database and Two Phase Publishing

Perhaps the most significant difference in approach for cl-blog-generator is its use of a database and an explicit publish step. With cl-blog-generator a draft can exist anywhere in the filesystem, and must be "published" to be recognised by the blog site generator. The publishing process fills in some default metadata, such as post date, if this is not originally specified, copies the modified draft to a configurable location, and enters the metadata into the database. This ensures that the post is completely specified by its representation in the filesystem, and that the database is recreatable.

The database enables the partial regeneration of the site, without having to parse the whole site, and makes the linking of content much simpler. However, having Elephant as a dependency is probably the largest impediment to installation at present.

On Titles, Dates, Tags and Filenames

cl-blog-generator's input XHTML has been augmented to add elements for specifying post title, date, update date (which I believe is missing from the other systems), slug, description, and tags. On publising (see next section), any of these elements that is missing, except the mandatory title, is filled in with defaults.

Both Chronicle and Jekyll use a preamble to specify metadata, with the filename being used to generate the post's slug. Jekyll also uses the filename and its path for specifying the post date, and tags.

Bells and Whistles

Finally, here is a grab bag of features.

  • Chronicle comes with a commenting system.

  • cl-blog-generator generates a meta description element, which is used by search engines to generate link text. It also generates meta elements with links to the previous and next posts.

  • Jekyll has a "Related posts" feature for generating links to similar posts.

  • Chronicle and Jekyll both have migration scripts for importing content.
  • Chronicle has a spooler for posting pre- written content at specific times

New Advogato Features

New HTML Parser: The long-awaited libxml2 based HTML parser code is live. It needs further work but already handles most markup better than the original parser.

Keep up with the latest Advogato features by reading the Advogato status blog.

If you're a C programmer with some spare time, take a look at the mod_virgule project page and help us with one of the tasks on the ToDo list!