Tags

Tags are the hub's shared vocabulary. A member types a word into a Tags field on a resource, a group, a wiki page, a support ticket or a profile, and that word becomes a link that gathers everything else carrying it. This chapter covers the administrator's side: the tag list, aliases, merging, tagged items, relationships and focus areas. The Hub users book covers what members see at /tags.

Almost nothing here is about creating tags. Members create them, in their hundreds, by typing; your job is to tidy up after them. A hub two years old has machine-learning, machine learning, ML and Machine Learning all in use, splitting the same body of work across four tag pages that each look half-empty. Merging those four into one is the characteristic task of this component, and the rest of the screens exist to support it.

That makes tags different from categories elsewhere in the hub. A category is a list you define and content is filed into. A tag is whatever somebody typed. You cannot stop a member inventing a new one, and there is no approval step — so a tag vocabulary is curated after the fact or not at all.

Open it under Components > Tags. Four sub-menu links sit at the top left: Tags, the list below; Relationships; Focus Areas; and Plugins, which opens the Plugin Manager filtered to the tags folder. The Plugins link appears only if you may manage plugins.

Tags

The list shows every tag in the system with these columns.

Column	Notes
Raw Tag	The word or phrase as it was typed.
Tag	The normalized form: transliterated to ASCII, lowercased, with every non-alphanumeric character stripped. "N.Y.", "NY" and "ny" all normalize to ny.
Type	User, Admin or Core.
# tagged	How many items carry the tag. The number links to the Tagged Items screen filtered to this tag.
Aliases	How many aliases the tag has.
Created	When the tag was first created, or (unknown).

Click any column heading to sort by it; click again to reverse. Above the list, Search (raw tag) matches a term against the tag, its raw tag, and its aliases, then press Go. The Filter menu narrows the list to All tags (default), User tags or Admin tags.

The toolbar offers:

• Options — the component's configuration; see Options.
• Re-calculate # Tagged and Aliases — recount the checked tags' items and aliases and store the totals.
• Pierce — copy one tag's items onto another; see Piercing.
• Merge — fold two or more tags into one; see Merging.
• New — create a tag.
• Delete — remove the checked tags after a confirmation. This deletes the tag, its aliases, and every association it has with content. It is permanent.
• Help — the built-in help screen.

Creating or editing a tag

Field	Notes
Type	User, Core or Admin. Admin tags are hidden from the site: they do not appear in tag clouds, autocompletion or search results for anyone without the Manage permission. They are a way to attach metadata that is not meant for visitors. A new tag defaults to Admin.
Raw Tag	Required. The tag as it should be displayed. Up to 250 characters.
Tag	Read-only. The normalized form, generated from the raw tag when you save.
Alias	A comma-separated list of alternate spellings, abbreviations or synonyms. See Aliases.
Description	Free text shown above the results on the tag's page on the site.

The panel beside the form shows the tag's ID, Creator and Created date, and, once the tag has been edited, Modifier and Modified. Below that, Activity log lists up to the last hundred recorded actions on the tag — created, edited, aliases added or removed, associations moved, copied or deleted — each with a timestamp and the person responsible.

Press Save to save and stay, Save & Close to return to the list, or Cancel to discard.

Aliases

An alias maps one spelling onto another. Give the tag "water" the aliases h2o, aqua and a member who types "aqua" ends up with the tag "water" instead; the alias itself is never stored on the item.

Merging

Merging is how you fix a split vocabulary. It is the only action here that consolidates rather than destroys: everything tagged with any of the source tags comes out tagged with the destination, and the old spellings survive as aliases, so a member who types one of them still lands in the right place.

Check two or more tags and press Merge. The next screen lists the tags you chose, each with the number of items using it, and asks for the tag to merge into. Type it into the Tag field — it may be an existing tag, one of the tags being merged, or an entirely new name, which is created for you. Press Save & Close to finish.

Merging moves every item association and every alias from the source tags onto the destination, adds each source tag's raw text as an alias of the destination, and then deletes the source tags. There is no undo.

Merging four spellings into one

Taking the machine learning example from the top of the chapter:

1. In Components > Tags, type machine into Search (raw tag) and press Go. The variants appear together; the # tagged column shows how much content each is holding.
2. Decide which one wins. Prefer the one with the most items — the fewest associations move, and the tag page most people already link to keeps working.
3. Tick the losing spellings. Leave the winner unticked; you do not have to include it, and naming it as the destination is enough.
4. Press Merge. Type the winning tag's text into the Tag field exactly as it should read, and press Save & Close.
5. Open the surviving tag and check its Alias field. The old spellings are now aliases, which is what redirects the next member who types one.
6. Look at # tagged. If it has not moved, tick the tag and press Re-calculate # Tagged and Aliases — the count is stored, not counted live.

Everything that carried the old tags now carries the new one, on every component of the hub, and nobody was notified. That is normally what you want; it also means a mistake here is visible to members immediately and is not something you can put back.

Piercing

Piercing is the non-destructive relative of merging. Check the tags, press Pierce, and name a destination tag in the New Tag field. Every item carrying the checked tags is also tagged with the destination. The original tags and their associations are left exactly as they were.

Tagged Items

The Tagged Items screen lists individual tag-to-item links. Reach it by clicking a number in the # tagged column, which filters it to that tag, or from a Tagged Items link. Columns are ID, Tag ID (hidden when the list is already filtered to one tag), Item Type, Item ID, Created and Creator. The Filter menu lists the item types actually present, and defaults to All Types.

New and Delete are the only toolbar actions besides Help. The edit form takes three required fields: Tag ID, Item ID and Item type — the last usually a component name without the com_ prefix, such as wishlist or blog. Deleting a row removes the tag from that item; it does not touch the tag or the item.

Relationships

Relationships draws a tag and its neighbours as a force-directed graph. Type a tag into Find tag, choose labels and hierarchy or implicit, and press Lookup. The hierarchical view follows the parent and label links you have defined, up to seven levels deep. The implicit view infers relationships from co-occurrence: tags that appear on the same items, weighted by how often, ignoring pairs that occur only once.

Click a node and the Metadata panel below fills in with its Description, Labeled, Labels, Parents and Children. Edit those lists and press Update to save. Naming a tag that does not exist yet creates it.

Focus Areas

Focus areas are groups of tags offered as a structured choice during resource submission, rather than as free typing. Each group has a Group name — itself a tag, whose children are the choices — a set of resource types it applies to, whether it is optional, mandatory, or mandatory until depth n, and whether choices are multiple-select (checkbox), single-select (radio), or single-select until a depth. Add group appends a group, Delete group removes one, and Save writes the whole set.

Tags nested more deeply than the mandatory level are presented as an optional, multiple-selection box.

Options

The Options button opens the component configuration. Ten Focus Area fields name tags used by the tool contribution workflow in Tools, and two cache settings control whether the tag clouds on /tags are cached and for how long. Every option is listed with its values in the configuration reference.

The Permissions tab sets, per user group, who may configure the component, manage it, and create, delete, edit, or change the state of tags. Manage is what admits you to the administrator screens at all, and it is also what lets a person see admin tags on the site.

Plugins

The tags plugins decide what a tag's page on the site can find. Each one searches its own component and contributes a category to the results: Questions & Answers, Blogs, Citations, Collections, Courses, Events, Forum, Groups, Knowledge Base, Members, Publications, Resources, Support Tickets and Wiki Pages. The Resources and Publications plugins go further and split their results into sub-categories by resource type.

Disable a plugin and its content disappears from tag pages. Each plugin applies its own component's visibility rules, so results differ by who is looking: guests see only public groups, members see groups they belong to, and profiles are filtered by access level.

API

The component exposes endpoints under /api/tags for listing, reading, creating, updating and deleting tags, and for adding a tag to or removing it from an item. See the API reference.