Show all tags related to a category? Is it possible to show all tags that are related to a category? I can't find anything on it.

Thanks.

Edit:

What I am looking for is this:

I know a category slug or name. I want to get all tags associated with entries in that category.

I can't seem to get this to work using the relatedTo param.
You can use the relatedTo param on craft.tags like you can with any Element inside Craft.

All Elements inside Craft can be related to one another. There is a .relatedTo parameter available on all of the query elements like craft.entries and craft.tags.  

You will need to pass a category object into this relatedTo parameter. I have included the group param below but this can be omitted if you want to query all of your tags.

{% set tags = craft.tags.group( 'groupName' ).relatedTo( category ) %}

More info on using Relations in Craft: https://craftcms.com/docs/relations



UPDATE

The relatedTo param takes one of the following:


An AssetFileModel, CategoryModel, EntryModel, UserModel, or TagModel
object 
An element’s ID 
An array of element objects and/or IDs


To get a CategoryModel using a slug inside your template you can use:

{% set category = craft.categories.slug( 'theslug' ).first() %}

This will set category to a CategoryModel which you can then use inside the .relatedTo param in the above example.



UPDATE 2

If you've set category to have their own URL's then category inside the template you've set to use is a CategoryModel.

You then set entries to all entries related to the category. Finally, use these entries to get all related tags.

{% set entries = craft.entries.relatedTo( category ).find() %}
{% set tags = craft.tags.relatedTo( entries ).find() %}