TiddlyWiki5/editions/tw5.com/tiddlers/mechanisms/BootMechanism.tid

title: BootMechanism
tags: docs mechanism

!Introduction

TiddlyWiki5 is based on a 1,000 line boot kernel that runs on node.js or in the browser, with all other functionality added via dynamically loaded modules.

The kernel boots just enough of the TiddlyWiki environment to allow it to load tiddlers and execute JavaScript modules. Plugin modules are written like `node.js` modules.

There are many [[different types of module|ModuleType]]: parsers, serializers, deserializers, macros etc. It goes much further than you might expect. For example, individual tiddler fields are modules, too: there's a module that knows how to handle the `tags` field, and another that knows how to handle the special behaviour of the `modified` and `created` fields.

Some plugin modules have further sub-plugins: the wikitext parser, for instance, accepts rules as individual plugin modules.

!Plugins and Modules

In TiddlyWiki5, [[Plugins]] are bundles of tiddlers that are distributed and managed as one; [[Modules]] are JavaScript tiddlers with a module type identifying when and how they should be executed.

The tiddler [[$:/core/boot.js]] is a barebones TiddlyWiki kernel that is just sufficient to load the core plugin modules and trigger a startup module to load up the rest of the application.

The kernel includes:

* Several short shared utility functions
* A handful of methods implementing the plugin module mechanism
* The `$tw.Tiddler` class (and field definition plugins)
* The `$tw.Wiki` class (and tiddler deserialization methods)
* Code for the browser to load tiddlers from the HTML DOM
* Code for the server to load tiddlers from the file system

Each module is an ordinary `node.js`-style module, using the `require()` function to access other modules and the `exports` global to return JavaScript values. The boot kernel smooths over the differences between `node.js` and the browser, allowing the same plugin modules to execute in both environments.

In the browser, `core/boot.js` is packed into a template HTML file that contains the following elements in order:

* Ordinary and shadow tiddlers, packed as HTML `<DIV>` elements
* `core/bootprefix.js`, containing a few lines to set up the plugin environment
* JavaScript modules, packed as HTML `<SCRIPT>` blocks
* `core/boot.js`, containing the boot kernel

On the server, `core/boot.js` is executed directly. It uses the `node.js` local file API to load plugins directly from the file system in the `core/modules` directory. The code loading is performed synchronously for brevity (and because the system is in any case inherently blocked until plugins are loaded).

The boot kernel sets up the `$tw` global variable that is used to store all the state data of the system.
Docs update 2012-08-04 10:20:47 +00:00			`title: BootMechanism`
Lots of documentation updates More to come... 2012-06-10 12:40:53 +00:00			`tags: docs mechanism`
Updated docs 2012-05-04 16:46:01 +00:00
			`!Introduction`
Fixed docs to work with new wikitext parser Which turns out to be entirely a matter of inserting additional blank lines, which has the beneficial effect of making the wikitext a lot more readable 2012-06-04 11:25:54 +00:00
Admit to the true size of the boot kernel 2012-11-16 22:47:05 +00:00			`TiddlyWiki5 is based on a 1,000 line boot kernel that runs on node.js or in the browser, with all other functionality added via dynamically loaded modules.`
Updated docs 2012-05-04 16:46:01 +00:00
Docs update 2012-08-04 10:20:47 +00:00			The kernel boots just enough of the TiddlyWiki environment to allow it to load tiddlers and execute JavaScript modules. Plugin modules are written like `node.js` modules.
Updated docs 2012-05-04 16:46:01 +00:00
Docs updates Trying to get the plugin documentation into shape 2012-08-30 12:55:28 +00:00			There are many [[different types of module\|ModuleType]]: parsers, serializers, deserializers, macros etc. It goes much further than you might expect. For example, individual tiddler fields are modules, too: there's a module that knows how to handle the `tags` field, and another that knows how to handle the special behaviour of the `modified` and `created` fields.
Updated docs 2012-05-04 16:46:01 +00:00
Docs update 2012-08-04 10:20:47 +00:00			`Some plugin modules have further sub-plugins: the wikitext parser, for instance, accepts rules as individual plugin modules.`
Updated docs 2012-05-04 16:46:01 +00:00
			`!Plugins and Modules`
Fixed docs to work with new wikitext parser Which turns out to be entirely a matter of inserting additional blank lines, which has the beneficial effect of making the wikitext a lot more readable 2012-06-04 11:25:54 +00:00
Docs updates Trying to get the plugin documentation into shape 2012-08-30 12:55:28 +00:00			`In TiddlyWiki5, [[Plugins]] are bundles of tiddlers that are distributed and managed as one; [[Modules]] are JavaScript tiddlers with a module type identifying when and how they should be executed.`
Update docs and readme generation 2012-05-05 22:08:00 +00:00
Docs updates Trying to get the plugin documentation into shape 2012-08-30 12:55:28 +00:00			`The tiddler [[$:/core/boot.js]] is a barebones TiddlyWiki kernel that is just sufficient to load the core plugin modules and trigger a startup module to load up the rest of the application.`
Update docs and readme generation 2012-05-05 22:08:00 +00:00
			`The kernel includes:`
Fixed docs to work with new wikitext parser Which turns out to be entirely a matter of inserting additional blank lines, which has the beneficial effect of making the wikitext a lot more readable 2012-06-04 11:25:54 +00:00
Docs updates Trying to get the plugin documentation into shape 2012-08-30 12:55:28 +00:00			`* Several short shared utility functions`
			`* A handful of methods implementing the plugin module mechanism`
			* The `$tw.Tiddler` class (and field definition plugins)
			* The `$tw.Wiki` class (and tiddler deserialization methods)
Update docs and readme generation 2012-05-05 22:08:00 +00:00			`* Code for the browser to load tiddlers from the HTML DOM`
			`* Code for the server to load tiddlers from the file system`

			Each module is an ordinary `node.js`-style module, using the `require()` function to access other modules and the `exports` global to return JavaScript values. The boot kernel smooths over the differences between `node.js` and the browser, allowing the same plugin modules to execute in both environments.

			In the browser, `core/boot.js` is packed into a template HTML file that contains the following elements in order:

			* Ordinary and shadow tiddlers, packed as HTML `<DIV>` elements
			* `core/bootprefix.js`, containing a few lines to set up the plugin environment
Docs updates Trying to get the plugin documentation into shape 2012-08-30 12:55:28 +00:00			* JavaScript modules, packed as HTML `<SCRIPT>` blocks
Update docs and readme generation 2012-05-05 22:08:00 +00:00			* `core/boot.js`, containing the boot kernel

			On the server, `core/boot.js` is executed directly. It uses the `node.js` local file API to load plugins directly from the file system in the `core/modules` directory. The code loading is performed synchronously for brevity (and because the system is in any case inherently blocked until plugins are loaded).

			The boot kernel sets up the `$tw` global variable that is used to store all the state data of the system.