Relations and backlinks

A relation is a typed link between Objects. Give your Book Type an author relation that points to Person, and each Book links to a real Person Object instead of a name typed as text. Open that Person and the Books they wrote are listed automatically as backlinks, and they appear as connections in the graph.

A relation declares its target Type and whether it holds one link or many. The link picker only offers Objects of the target Type, including Objects of its subtypes.

Add a relation to a Type

1. Open Object type settings → Properties and choose Add Property.
2. Pick Object Select.
3. Enter a Name, such as author.
4. Under Linked object type, choose the target Type, such as Person.
5. Under Single or Multi-Select, choose Single or Multiple.
6. Select + Create.

The relation appears in the property list with an Object badge. Choose Edit on it to change the Linked object type, switch between Single and Multiple, Enable fixed set to limit choices to a predefined list of Objects, or set up two-way linking. The Relations section of Object type settings offers a compact form for adding and removing relations as well.

Removing a relation orphans the links on every Object of the Type and can’t be undone, so Lar asks you to confirm.

Link Objects

1. Open the Object and find the relation in its details panel, under Relations.
2. Choose + add and pick the target Object.

A Multiple relation can hold several links. A Single relation holds one, so + add disappears once it’s set; choose Remove link beside the current target to replace it.

Create a two-way relation

Two-way linking keeps two relations in step: add a Person as a Book’s author, and the Book is added to that Person’s books.

1. Create the relation on each Type, for example author on Book (target Person) and books on Person (target Book). Both must have the same cardinality, so make both Multiple; books can have co-authors.
2. Open one relation’s settings with Edit.
3. Under Two-way linking, choose the matching relation on the other Type.

After that, adding or removing a link on either side updates the other. Two-way linking is available only between your own custom Types, not built-in Types.

Tip

You don’t need a two-way relation just to see where an Object is referenced. Backlinks already show every Object that links to it. Pair relations when you want the link stored, and editable, on both Objects.

Mentions and backlinks

Typing [[Object title]] in a body creates a mention, a link maintained by Lar’s built-in mentions relation that you don’t need to declare. See Links and transclusion for how mentions look and behave in the editor.

The Linked from section of an Object’s details panel lists its backlinks: every Object that points to it through a mention, a tag, or any relation. How the section displays them is set per Type under Object type settings → Layout → Backlinks view.

The Unlinked mentions section finds plain-text uses of the Object’s title that aren’t links yet. Review each one before converting it, because matching words don’t always mean the same thing.

Link to part of an Object

Beyond whole-Object links, you can embed another Object’s content with ![[Title]] or ![[Title#section]], or point to one specific block. See Links and transclusion.

Next: Tags.