etherpad-lite/doc/api/changeset_library.md

# Changeset Library

The [changeset
library](https://github.com/ether/etherpad-lite/blob/develop/src/static/js/Changeset.js)
provides tools to create, read, and apply changesets.

## Changeset

```javascript
const Changeset = require('ep_etherpad-lite/static/js/Changeset');
```

A changeset describes the difference between two revisions of a document. When a
user edits a pad, the browser generates and sends a changeset to the server,
which relays it to the other users and saves a copy (so that every past revision
is accessible).

A transmitted changeset looks like this:

```
'Z:z>1|2=m=b*0|1+1$\n'
```

## Attribute Pool

```javascript
const AttributePool = require('ep_etherpad-lite/static/js/AttributePool');
```

Changesets do not include any attribute key–value pairs. Instead, they use
numeric identifiers that reference attributes kept in an [attribute
pool](https://github.com/ether/etherpad-lite/blob/develop/src/static/js/AttributePool.js).
This attribute interning reduces the transmission overhead of attributes that
are used many times.

There is one attribute pool per pad, and it includes every current and
historical attribute used in the pad.

## Further Reading

Detailed information about the changesets & Easysync protocol:

* [Easysync Protocol](https://github.com/ether/etherpad-lite/blob/develop/doc/easysync/easysync-notes.pdf)
* [Etherpad and EasySync Technical Manual](https://github.com/ether/etherpad-lite/blob/develop/doc/easysync/easysync-full-description.pdf)
-												Fix doc format, add in makefile for docs

OK, first up, SOMEBODY *cough*analphabet*cough* screwed up the docs
by making them all use the wrong heading level. Not cool, guy. I
had to change them so they would compile right.

But anyway, now the docs will build into sexy-looking HTML and will
shortly be hosted on marktraceur.info.

Fixed the makefile to work properly.

Run:
 * `make clean` for removing old doc-build(s)
 * `make docs` for running new doc-build(s)

											
										
										
											2012-08-14 04:03:06 +02:00
+								# Changeset Library
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								The [changeset
 								library](https://github.com/ether/etherpad-lite/blob/develop/src/static/js/Changeset.js)
 								provides tools to create, read, and apply changesets.
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								## Changeset
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								```javascript
 								const Changeset = require('ep_etherpad-lite/static/js/Changeset');
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
+								```
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								A changeset describes the difference between two revisions of a document. When a
 								user edits a pad, the browser generates and sends a changeset to the server,
 								which relays it to the other users and saves a copy (so that every past revision
 								is accessible).
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								A transmitted changeset looks like this:
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
 								```
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								'Z:z>1|2=m=b*0|1+1$\n'
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
+								```
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								## Attribute Pool
-												Fix markup.

											
										
										
											2012-08-07 20:29:44 +02:00
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								```javascript
 								const AttributePool = require('ep_etherpad-lite/static/js/AttributePool');
-												Fix markup.

											
										
										
											2012-08-07 20:29:44 +02:00
+								```
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								Changesets do not include any attribute key–value pairs. Instead, they use
 								numeric identifiers that reference attributes kept in an [attribute
 								pool](https://github.com/ether/etherpad-lite/blob/develop/src/static/js/AttributePool.js).
 								This attribute interning reduces the transmission overhead of attributes that
 								are used many times.
-												Fix markup.

											
										
										
											2012-08-07 20:29:44 +02:00
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								There is one attribute pool per pad, and it includes every current and
 								historical attribute used in the pad.
-												Add docs.

											
										
										
											2012-08-03 22:04:06 +02:00
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								## Further Reading
-												DOCS: Add basic styles for tables and resources section to Changeset docs - https://github.com/citizenos/citizenos-fe/issues/535

											
										
										
											2021-04-06 21:07:36 +02:00
 								Detailed information about the changesets & Easysync protocol:
-												Changeset: Minimize changeset docs, add links to code

This reduces the amount of duplicate documentation, and helps keep the
documentation and code in sync.

											
										
										
											2021-10-25 01:42:59 +02:00
+								* [Easysync Protocol](https://github.com/ether/etherpad-lite/blob/develop/doc/easysync/easysync-notes.pdf)
 								* [Etherpad and EasySync Technical Manual](https://github.com/ether/etherpad-lite/blob/develop/doc/easysync/easysync-full-description.pdf)