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Introduction to Yjs

FireSync is compatible with the Yjs library. Yjs provides data structures for fast and reliable collaboration and the Yjs data is syncronised between all clients by FireSync for you automatically.

The top level object in Yjs is a doc (Y.Doc) and each doc can contain Text, Maps and Arrays. Any nested combination of these types can be used in a single doc and they will be automatically synced between FireSync and anyone else subscribed to that doc. For example:

const doc = firesync.subscribeYDoc("my-document");
const ymap = doc.getMap("a");
const ytext = doc.getText("b");
const yarray = doc.getArray("c");


const doc = firesync.subscribeYDoc("my-document");

const ytext = doc.getText("foo");

// Inserting text
ytext.insert(0, "Hello");
ytext.insert(5, "world!");

// Retrieving the text
console.log(ytext.toString()); // Output: 'Hello world!'

See Y.Text in the Yjs documentation for more information.


const doc = firesync.subscribeYDoc("my-document");

const ymap = doc.getMap("foo");

// Setting a value
ymap.set("key1", "value1");
ymap.set("key2", "value2");

// Retrieving a value
console.log(ymap.get("key1")); // Output: 'value1'
console.log(ymap.get("otherKey")); // Set by a different user but available here too!

See Y.Map in the Yjs documentation for more information.


const doc = firesync.subscribeYDoc("my-document");
const yarray = doc.getArray("foo");

// Adding elements to the array

// Retrieving an element
console.log(yarray.get(0)); // Output: 'element1'

See Y.Array in the Yjs documentation for more information.


Yjs also supports XML documents, which are mostly useful for supporting some rich text which use XML as an underlying data structure. Y.XmlFragment, XmlText, and XmlElement are the three types of xml element available. The Yjs documentation has more information on these.

Further information

More details on the data types and Yjs can be found in the Yjs documentation.