created: 20170209145637233
modified: 20170209150007550
tags: HookMechanism
title: Hook: th-relinking-tiddler
type: text/vnd.tiddlywiki

This hook allows plugins to inspect tiddlers before they are relinked ("relinking" is the optional operation of relinking references to a tiddler when it is renamed).

Hook function parameters:

* ''newTiddler'': tiddler object incorporating the relinking
* ''oldTiddler'': optional existing tiddler object that will be overwritten

Return value:

* ''newTiddler'': tiddler object to be used for the relinking operation.

The original tiddler object can be returned unmodified by the hook. If the hook needs to modify the tiddler then it should return a new tiddler object, for example:

```
	return new $tw.Tiddler(tiddler,{"my-field": value});
```

Hooks must not change the ''title'' field but can freely modify any other field of the tiddler.