rib-0.6.0.0: README.md
# rib
[](https://en.wikipedia.org/wiki/BSD_License)
[](https://hackage.haskell.org/package/rib)
[](https://builtwithnix.org)
[](https://funprog.zulipchat.com/#narrow/stream/218047-Rib)
Rib is a Haskell library for writing your own **static site generator**.
How does it compare to Hakyll?
- Uses the [Shake](https://shakebuild.com/) build system at its core.
- Allows writing Haskell DSL to define HTML ([Lucid](https://chrisdone.com/posts/lucid2/)) & CSS ([Clay](http://fvisser.nl/clay/))
- Built-in support for [Pandoc](https://pandoc.org/) and [MMark](https://github.com/mmark-md/mmark), while also supporting custom parsers (eg: [Dhall](https://github.com/srid/website/pull/6), [TOML](https://github.com/srid/website/pull/7))
- Remain as simple as possible to use (see example below)
- Nix-based environment for reproducibility
- `ghcid` and fsnotify for "hot reload"
Rib prioritizes the use of *existing* tools over reinventing them, and enables
the user to compose them as they wish instead of having to write code to fit a
custom framework.
**Table of Contents**
- [rib](#rib)
- [Quick Preview](#quick-preview)
- [Getting Started](#getting-started)
- [Concepts](#concepts)
- [Directory structure](#directory-structure)
- [Run the site](#run-the-site)
- [How Rib works](#how-rib-works)
- [Editing workflow](#editing-workflow)
- [What's next?](#whats-next)
- [Examples](#examples)
## Quick Preview
Here is how your code may look like if you were to generate your static site
using Rib:
``` haskell
-- | A generated page corresponds to either an index of sources, or an
-- individual source.
--
-- Each `Source` specifies the parser type to use. Rib provides `MMark` and
-- `Pandoc`; but you may define your own as well.
data Page
= Page_Index [Source M.MMark]
| Page_Single (Source M.MMark)
-- | Metadata in our markdown sources. Parsed as JSON.
data SrcMeta
= SrcMeta
{ title :: Text,
-- | Description is optional, hence it is a `Maybe`
description :: Maybe Text
}
deriving (Show, Eq, Generic, FromJSON)
-- | Main entry point to our generator.
--
-- `Rib.run` handles CLI arguments, and takes three parameters here.
--
-- 1. Directory `a`, from which static files will be read.
-- 2. Directory `b`, under which target files will be generated.
-- 3. Shake build action to run.
--
-- In the shake build action you would expect to use the utility functions
-- provided by Rib to do the actual generation of your static site.
main :: IO ()
main = Rib.run [reldir|a|] [reldir|b|] generateSite
where
-- Shake Action for generating the static site
generateSite :: Action ()
generateSite = do
-- Copy over the static files
Rib.buildStaticFiles [[relfile|static/**|]]
-- Build individual sources, generating .html for each.
-- The function `buildHtmlMulti` takes the following arguments:
-- - File patterns to build
-- - Function that will parse the file (here we use mmark)
-- - Function that will generate the HTML (see below)
srcs <-
Rib.buildHtmlMulti M.parse [[relfile|*.md|]] $
renderPage . Page_Single
-- Write an index.html linking to the aforementioned files.
Rib.writeHtml [relfile|index.html|] $
renderPage (Page_Index srcs)
-- Define your site HTML here
renderPage :: Page -> Html ()
renderPage page = with html_ [lang_ "en"] $ do
head_ $ do
meta_ [httpEquiv_ "Content-Type", content_ "text/html; charset=utf-8"]
title_ $ case page of
Page_Index _ -> "My website!"
Page_Single src -> toHtml $ title $ getMeta src
style_ [type_ "text/css"] $ Clay.render pageStyle
body_
$ with div_ [id_ "thesite"]
$ do
with a_ [href_ "/"] "Back to Home"
hr_ []
case page of
Page_Index srcs ->
div_ $ forM_ srcs $ \src -> with li_ [class_ "links"] $ do
let meta = getMeta src
b_ $ with a_ [href_ (Rib.sourceUrl src)] $ toHtml $ title meta
maybe mempty (M.render . either (error . T.unpack) id . M.parsePure "<desc>") $ description meta
Page_Single src ->
with article_ [class_ "post"] $ do
h1_ $ toHtml $ title $ getMeta src
M.render $ Rib.sourceVal src
-- Get metadata from Markdown YAML block
getMeta :: Source M.MMark -> SrcMeta
getMeta src = case M.projectYaml (Rib.sourceVal src) of
Nothing -> error "No YAML metadata"
Just val -> case fromJSON val of
Aeson.Error e -> error $ "JSON error: " <> e
Aeson.Success v -> v
-- Define your site CSS here
pageStyle :: Css
pageStyle = "div#thesite" ? do
margin (em 4) (pc 20) (em 1) (pc 20)
"li.links" ? do
listStyleType none
marginTop $ em 1
"b" ? fontSize (em 1.2)
"p" ? sym margin (px 0)
```
(View full [`Main.hs`](https://github.com/srid/rib-sample/blob/master/Main.hs) at rib-sample)
## Getting Started
The easiest way to get started with [Rib](/) is to [use the
template](https://help.github.com/en/articles/creating-a-repository-from-a-template)
repository, [**rib-sample**](https://github.com/srid/rib-sample), from Github.
## Concepts
### Directory structure
Let's look at what's in the template repository:
```shell
$ git clone https://github.com/srid/rib-sample.git mysite
...
$ cd mysite
$ ls -F
a/ default.nix Main.hs README.md rib-sample.cabal
```
The three key items here are:
1. `Main.hs`: Haskell source containing the DSL of the HTML/CSS of your site.
1. `a/`: The source content (eg: Markdown sources and static files)
1. `b/`: The target directory, excluded from the git repository, will contain
_generated_ content (i.e., the HTML files, and copied over static content)
The template repository comes with a few sample posts under `a/`, and a basic
HTML layout and CSS style defined in `Main.hs`.
### Run the site
Now let's run them all.
Clone the sample repository locally, install [Nix](https://nixos.org/nix/) and
run your site as follows:
```shell
nix-shell --run 'ghcid -T main'
```
(Note even though the author recommends it Nix is strictly not required; you may
simply run `ghcid -T main` instead of the above command if you do not wish to
use Nix.)
Running this command gives you a local HTTP server at http://localhost:8080/
(serving the generated files) that automatically reloads when either the content
(`a/`) or the HTML/CSS/build-actions (`Main.hs`) changes. Hot reload, in other
words.
### How Rib works
How does the aforementioned nix-shell command work?
1. `nix-shell` will run the given command in a shell environment with all of our
dependencies (notably the Haskell ones including the `rib` library itself)
installed.
1. [`ghcid`](https://github.com/ndmitchell/ghcid) will compile your `Main.hs`
and run its `main` function.
1. `Main.hs:main` in turn calls `Rib.App.run` which takes as argument your custom Shake action that will build the static site.
1. `Rib.App.run`: this parses the CLI arguments and runs the rib CLI "app" which
can be run in one of a few modes --- generating static files, watching the
`a/` directory for changes, starting HTTP server for the `b/` directory. By
default---without any explicit arguments---this will run the Shake build
action passed as argument on every file change and spin up a HTTP server.
Run that command, and visit http://localhost:8080 to view your site.
### Editing workflow
Now try making some changes to the content, say `a/first-post.md`. You should
see it reflected when you refresh the page. Or change the HTML or CSS of your
site in `Main.hs`; this will trigger `ghcid` to rebuild the Haskell source and
restart the server.
### What's next?
Great, by now you should have your static site generator ready and running! What
more can you do? Surely you may have specific needs; and this usually translates
to running custom Shake actions during the build. Rib provides helper functions in `Rib.Shake` to make this easier.
Rib recommends writing your Shake actions in the style of being
[forward-defined](http://hackage.haskell.org/package/shake-0.18.3/docs/Development-Shake-Forward.html)
which adds to the simplicity of the entire thing.
## Examples
* [rib-sample](https://github.com/srid/rib-sample): Use this to get started with
your own site.
* Author's own website. Live at https://www.srid.ca/