twikifier

A node.js based wikifier for TiddlyWiki text.

What

This is a first pass at creating node.js-based wikifier for wikitext formatted as TiddlyWiki text.

Rather than creating new code this code simply assembles the required parts from the TiddlyWiki core code repository along with the necessary bits of additional JavaScript. This means that as the TiddlyWiki core changes this code automatically keeps up to date.

By using jsdom and htmlparser with node, it is possible to simulate the browser environment that the wikifier would normally run in, and create some HTML output.

How

(The below is for OS X but should transliterate to other environments. It has also been tested on Ubuntu 12.04)

Install node.js and its package manager npm. If you are using brew that goes like this:

brew install node npm

Once you have npm, install grunt with:

npm install -g grunt-cli

Then install the project dependencies:

npm install

In the repo directory run:

grunt

This will get all the necessary TiddlyWiki code and concatenate it into dist/twikifier.js. The grunt test task is run after this and runs all the files in the test/files directory against twikifier via test/twikify/js.

The task also creates a distributable node application in bin/server.js.

From the test directory, you can try your own wikitext by piping data into twikify on STDIN:

node twikify.js --collection=<url for tiddler collection> < /tmp/mysampledata.txt

or by giving the names of multiple files on the command line:

node twikify.js --collection=<url for tiddler collection> /tmp/mysampledata.txt \
    /tmp/someotherdata.txt

<url for tiddler collection> should be replaced with the url of a collection of tiddlers, in JSON, as found in TiddlyWeb. Things like:

http://cdent-test7.tiddlyspace.com/bags/cdent-test7_public/tiddlers
http://cdent-test7.tiddlyspace.com/recipes/cdent-test7_public/tiddlers

As the tool develops there will be other interfaces.

Testing the NPM Package Works

From the repo directory run:

npm pack

This will create a zipped tarball. Install this tarball as follows:

npm install -g twikifier-x.y.z.tgz

If all is well, twikifier will be available in your path. Run this to check twikifier works.

Releasing the NPM Package

Run:

grunt release

See this link for how this works.

Use with TiddlyWeb and Tiddlyspace

Copy twikified.py into the folder where the instance is running.

Add 'twikified' to the list of system plugins in tiddlywebconfig.py.

Install this package via NPM then run the twikifier server:

npm install -g twikifier
twikifier

Then start TiddlyWeb/Tiddlyspace

If you have connection problems after a restart, remove /tmp/wst.sock and try again.

To permantly run twikifier, see the next section.

To have twikifier automatically run on start-up and to give more control over starting and stopping it:

Copy the file scripts/twikifier to /etc/init.d/

Test it can start and stop:

sudo /etc/init.d/twikifier start
sudo /etc/init.d/twikifier stop
sudo /etc/init.d/twikifier restart

Enable the script to start-up automatically on boot:

update-rc.d twikifier defaults

Credit goes to https://github.com/chovy/node-startup for this.

Why

TiddlyWeb and friends use WikklyText to do sever-side rendering of TiddlyWiki text to HTML. It works, but not great. It has long been thought that a transcoding of the TiddlyWiki wikifier would a) work better, b) be easier to extend and modify.

Also see the next section.

Comments

In order to get the TiddlyWiki wikifier to work standalone, a great deal of the TiddlyWiki code is required. Have a look at TWREMOTES in the Makefile and the comments in TwikifierBase.js. The general overview comment is that TiddlyWiki is non-functional: meaning its modules and methods are tightly coupled with others, have many side effects and make use of data from globals rather than passed in parameters. This means that independent code reuse is nigh on impossible.

That this is true is neither surprising, nor damning: TiddlyWiki was originally built as a single file application. However since there is code in there that could be useful if extracted and abstracted, hopefully this work can point out some of the problems.

I tried to write down a simple dependency tree that explains how each chunk of javascript requires another, but delineating the reasons got to be too much so instead: What follows has less explanation than it could.

twikifier functionality currently lives in twikify and TwikifierBase.js.

twikify requires global wikify() in Wikifier.js.

Wikifier.js requires the global formatter, a Formatter from FormatterHelpers.js.

FormatterHelpers.js requires the global config, from Config.js.

A Formatter needs formatters, which are in config and defined in Formatter.js.

Formatter.js requires FormatterHelper.js, creating a cycle.

Wikifier.js requires global createTiddlyText(), from Utilities.js.

Wikifier.js requires global createTiddlyElement(), from Utilities.js.

Formatter.js, to format links, requires global createTiddlyLink() from Utilities.js.

Utilities.js requires the pushUnique modification to the Array prototype. This is found in BasicTypes.js.

Formatter.js, FormatterHelpers.js, Utilities.js all make use of a store global. A store, is a TiddlyWiki class, from TiddlyWiki.js.

TiddlyWiki.js calls instanceof Tiddler (4 times) and new Tiddler (twice), thus requiring Tiddler.js.

Utilities.js has getTiddlyLinkInfo, which requires Lingo.js for messages. (Lingo.js requires Config.js and Utilities.js (for merge()).)

Presenting messages requires adding format() to the String prototype, thus requiring Strings.js.

This gets us to a working formatter, but not macros.

Adding Macros.js adds (limited, not yet tested) support for macros. Macros.js requires Config.js.

For macros to run, we need invokeMacro, which is from main.js. Rather than including main.js (which has active code at the global level) I made a copy of invokeMacro. It is not clear why the function definition code is in main.

The difficulty here is not so much that there are a bunch of interdependencies, but rather that the interdependencies are in the global scope and because the files are simply building blocks for a single file, there are no clues like import statements, namespaces, etc.

Next

While the existing code will do basic rendering, to be truly useful in a TiddlyWeb situation, twikifier needs two things:

  • To present a web service or local socket that takes an input (a text string, a tiddler bag/title combo?) and returns the generated HTML.

  • The Python code that provides the plugin hook for TiddlyWeb should live in a seperate repository and be installed via pip.

Who

twikifier is written by Chris Dent and is Copyright 2011, Peermore Limited using a New BSD License.