gostatic

gostatic

Gostatic is a static site generator. What differs it from most of other tools is that it's written in Go and tracks changes, which means it should work reasonably fast.

Features include:

• No run-time dependencies, just a single binary - download it and run
• Dependency tracking and re-rendering only changed pages
• Markdown support
• Flexible filter system
• Simple config syntax
• HTTP server and watcher (instant rendering on changes)

Binary builds:

If you want to download specific version, url pattern is http://solovyov.net/files/gostatic-<version>-<32/64>-<win.exe/linux/osx>.

Examples of use: my site or run gostatic -i name to generate example site in directory name.

Documentation index:

• Approach
• Speed
• External Resources
• Configuration
  • Constants
• Page config
• Processors
• Templating
  • Global Functions
  • Page interface
  • Page list interface
  • Site interface

Approach

Each given file is processed through a pipeline of filters, which modify the state and then rendered on disk. Single input file corresponds to a single output file, but filters can generate virtual input files.

Each file can have dependencies, and will be rendered in case it does not exist, or its source is newer than output, or one of this is the case for one of its dependencies.

All read pages are sorted by date. This date is taken in their config or, in case if config is absent or dates there are equal, by file modification time.

Speed

On late 2008 MacBook (C2D 2.4 GHz, 8 GB RAM, 5400 rpm HDD) it takes 0.3s to generate a site of 250 pages. It costs 0.05s to check there are no modifications and 0.1s to re-render a single changed page (along with index and tag pages, coming to 77 pages in total).

External resources

• Jack Pearkes wrote Heroku buildpack for gostatic and an article about it.

Configuration

Config syntax is Makefile-inspired with some simplifications, look at the example:

TEMPLATES = site.tmpl
SOURCE = src
OUTPUT = site

# this is a comment
*.md:
    config
    ext .html
    directorify
    tags tags/*.tag
    markdown
    template page # yeah, this is a comment as well

index.md: blog/*.md
    config
    ext .html
    inner-template
    markdown
    template page

*.tag: blog/*.md
    ext .html
    directorify
    template tag
    markdown
    template page

Here we have constants declaration (first three lines), a comment and then three rules. One for any markdown file, one specifically for index.md and one for generated tags.

Note: Specific rules override matching rules, but there is no very smart logic in place and matches comparisons are not strictly defined, so if you have several matches you could end up with any of them. Though there is order: exact path match, exact name match, glob path match, glob name match. NOTE: this may change in future.

Rules consist of path/match, list of dependencies (also paths and matches, the ones listed after colon) and commands.

Each command consists of a name of processor and (possibly) some arguments. Arguments are separated by spaces.

Note: if a file has no rules whatsoever, it will be copied to exactly same location at destination as it was in source without being read into memory. So heavy images etc shouldn't be a problem.

Constants

There are three configuration constants. SOURCE and OUTPUT speak for themselves, and TEMPLATES is a list of files which will be parsed as Go templates. Each file can contain few templates.

You can also use arbitrary names for constants to access later from templates.

Page config

Page config is only processed if you specify config processor for a page. It's format is name: value, for example:

title: This is a page
tags: test
date: 2013-01-05

Parsed properties:

• title - page title.
• tags - list of tags, separated by ,.
• date - page date, could be used for blog. Accepts formats from bigger to smaller (from "2006-01-02 15:04:05 -07" to "2006-01-02")

You can also define any other property you like, it's value will be treated as a string and it's key is capitalized and put on the .Other page property.

Processors

You can always check list of available processors with gostatic --processors.

• config - reads config from content. Config should be in format "name: value" and separated by four dashes on empty line (----) from content.

• ignore - ignore file.

• rename <new-name> - rename a file to new-name. New name can contain *, then it will be replaced with whatever * captured in path match. Right now rename touches whole path, so be careful (you may need to include whole path in rename pattern) - this may change in future.

• ext <.ext> - change file extension to a given one (which should be prefixed with a dot).

• directorify - rename a file from whatever/name.html to whatever/name/index.html.

• markdown - process content as Markdown.

• inner-template - process content as Go template.

• template <name> - pass page to a template named <name>.

• tags <path-pattern> - create (if not yet) virtual page for all tags of a current page. This tag page has path formed by replacing * in <path-pattern> with a tag name.

• relativize - change all urls archored at / to be relative (i.e. add appropriate amount of ../) so that generated content can be deployed in a subfolder of a site.

• external <command> <args...> - call external command with content of a page as stdin and using stdout as a new content of a page. Has a shortcut: :<command> <args...> (: is replaced with external ).

Templating

Templating is provided using Go templates. See link for documentation on syntax.

Each template is executed in context of a page. This means it has certain properties and methods it can output or call to generate content, i.e. {{ .Content }} will output page content in place.

Global functions

Go template system provides some convenient functions, and gostatic expands on that a bit:

• changed <name> <value> - checks if value has changed since previous call with the same name. Storage, used for checking, is global over whole run of gostatic, so choose unique names.

• cut <value> <begin> <end> - cut partial content from <value>, delimited by regular expressions <begin> and <end>.

• hash <value> - return 32-bit hash of a given value.

• version <path> - return relative url to a page with resulting path <path> with ?v=<32-bit hash> appended (used to override cache settings on static files).

Page interface

• .Site - global site object.
• .Rule - rule object, matched by page.
• .Pattern - pattern, which matched this page.
• .Deps - list of pages, which are dependencies for this page.

• .Source - relative path to page source.
• .FullSource - full path to page source.
• .Path - relative path to page destination.
• .FullPath - full path to page destination.
• .ModTime - page last modification time.

• .Title - page title.
• .Tags - list of page tags.
• .Date - page date, as defined in page config.
• .Other - map of all other properties (capitalized) from page config.

• .Content - page content.
• .Url - page url (i.e. .Path, but with index.html stripped from the end).
• .UrlTo <other-page> - relative url from current to some other page.
• .Rel <url> - relative url to given absolute (anchored at /) url.
• .Is <url> - checks if page is at passed url (or path) - use it for marking active elements in menu, for example.
• .UrlMatches <pattern> - checks if page url matches regular expression <pattern>.

Page list interface

• .Get <n> - page number <n>.
• .First - first page.
• .Last - last page.
• .Len - length of page list.
• .Prev <page> - return page with earlier date than given. Returns nil if no earlier pages exist or page is not in page list.
• .Next <page> - return page with later date than given. Returns nil if no later pages exist or page is not in page list.

• .Children <prefix> - list of pages, nested under <prefix>.
• .WithTag <tag-name> - list of pages, tagged with <tag-name>.

• .BySource <path> - finds a page with source path <path>.
• .ByPath <path> - finds a page with resulting path <path>.

Site interface

• .Pages - list of all pages.
• .Source - path to site source.
• .Output - path to site destination.
• .Templates - list of template files used for the site.
• .Other - any other properties (capitalized) defined in site config.