# Editing topic title/category or tag does not re-render docked header

**URL:** <https://meta.discourse.org/t/editing-topic-title-category-or-tag-does-not-re-render-docked-header/54468>\
**Category:** Bug\
**Created:** [December 19, 2016, 3:31am UTC](https://meta.discourse.org/t/editing-topic-title-category-or-tag-does-not-re-render-docked-header/54468 "2016-12-19T03:31:39Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![eviltrout](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/eviltrout/32/5275_2.png) [@eviltrout](https://meta.discourse.org/u/eviltrout)\
**Post date:** [December 19, 2016, 5:29pm UTC](https://meta.discourse.org/t/editing-topic-title-category-or-tag-does-not-re-render-docked-header/54468/3 "2016-12-19T17:29:14Z")

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In cases where components don’t exist in a hierarchy (for example, header and main body) I prefer to use our injected `appEvents` object to signal things like this. In fact, there is already a `header:show-topic` event that is triggered when the topic is changed while browsing around. So the fix was just to trigger that after the topic was updated:

[https://github.com/discourse/discourse/commit/05e99a68cec550eb3b1aa9703bdca462e74303e7](https://github.com/discourse/discourse/commit/05e99a68cec550eb3b1aa9703bdca462e74303e7)

Over time I learned to loathe observers. They still have some uses in our codebase but if there’s a way I can instead say “okay, signal that something changed”, preferably by action handler, I’ll always do that.

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