URLs

How the hub turns an address into an article, and how to point an old address at a new one.

An address matters more on a hub than on an ordinary site, because hub addresses end up in places you cannot edit later: a methods section, a grant report, a data availability statement, a link in somebody else's paper. Once /about/citing is in print it has to keep working. This chapter is about knowing which address a page really has before you publish it, and about keeping an old one alive after you move things.

Most managers need two things from it. The first is the rule that an article's URL comes from the menu item pointing at it, not from anything you typed on the article. The second is the Redirect Manager, for the day somebody reorganises the site.

The SEO settings

Search engine friendly URLs are configured in Site → Global Configuration, on the Site tab, under SEO Settings.

Setting	Default	What it does
Search Engine Friendly URLs	Yes	Builds path-style URLs instead of query strings.
Search Engine Friendly Group URLs	No	Nothing. The setting is stored but no code reads it.
Use URL rewriting	Yes	Drops index.php from the path. Needs the web server's rewrite rules in place first.
Adds Suffix to URL	No	Appends the document format, so a page ends in .html.
Unicode Aliases	No	Lets aliases hold non-ASCII characters instead of transliterating them.

These are also listed in the global configuration reference.

Leave these alone. The shipped values are the ones a hub wants: friendly URLs on, rewriting on, everything else off.

Rewriting is the one setting here that can take the site down. It works only while the web server has the matching rewrite rules; turn it on where they are missing and every page on the hub 404s. That is not an afternoon change on a live site. If you must change it, change it, load one page, and be ready to change it straight back.

How an article's address is decided

Two things can give an article a URL, and the first one wins.

A menu item

If any menu item points at the article, the article's URL is that menu item's route: its own alias, with the aliases of its parent menu items in front of it. This is how the pages that ship with a hub are addressed. The sample Terms of Use article is reached at /about/terms because a menu item with alias terms, nested under a menu item with alias about, points at it. The article's own alias, terms, and its category, about, play no part — they happen to match here, and often will not.

Menu item routes are the addresses to publish and to link to. See Menus.

The category path

An article with no menu item is matched by its category path and its own alias:

/{category-path}/{article-alias}

The category path is the nested path of the category the article is in, so an article with alias site in a category this nested under a category about answers at /about/this/site. Only published articles are found this way.

Two shorthands exist for a single-segment address, /{alias}:

• The article is in the Uncategorised category. This is the ordinary case for a page you want at the top level: file it under Uncategorised and it answers at /{alias}.
• Every segment of the article's category path is the same word as the article's alias. An article about in category about answers at /about. The code calls this out as supported for legacy reasons; do not build anything new on it.

Category path	Article alias	URL
(Uncategorised)	terms	/terms
about	site	/about/site
about/this	site	/about/this/site
about	about	/about

If nothing matches, the hub falls back to the component router, which addresses an article as /content/article/{category-path}/{article-alias} and a category as /content/category/{path}. Those addresses work, but they are ugly and no one should be given them.

Redirects

Suppose the hub has grown and the About material is being split up: the page that has answered at /about for three years becomes /about/overview, and a citation page moves in alongside it. The old address is in a funder report. A redirect is how you keep it working.

The Redirect Manager is the supported way to send one address to another. Open it at Site → Maintenance → Routes.

To catch that address:

1. Go to Site → Maintenance → Routes and select New.
2. Put the old address in Source URL — /about.
3. Put the new one in Destination URL — /about/overview.
4. Set Response Code to 301 Moved Permanently, because the move is permanent and you want search engines and citation checkers to learn the new address.
5. Save, and make sure the link is enabled. A link with no destination, or a disabled one, does nothing.
6. Open /about in a browser. It should land on /about/overview.

Redirects are entirely reversible: disable the link and the old address goes back to a 404. Nothing about a redirect touches the article itself.

The manager depends on the System - Redirect plugin, and says at the top of the screen whether that plugin is enabled. With it on, every 404 the site serves is recorded as a link with no destination, so the manager doubles as a list of the broken addresses people are actually asking for.

A link has:

Field	Meaning
Source URL	The address to catch. Required, and must be unique. The plugin matches the full URL, then the server-relative path with and without a leading slash.
Destination URL	Where to send them. Required to enable the link.
Response Code	404 Not Found, 301 Moved Permanently, or 302 Found. A new link with a destination defaults to 302.
Comment	A note for whoever reads the list next.

Enable a link and the redirect takes effect; disable it and the address goes back to a 404. The toolbar also archives, trashes, and — once you filter to Trashed — permanently deletes links. This screen is one of the well behaved ones: trashing is reversible and the permanent delete is a separate button you can only reach after filtering to Trashed. See States, deleting and check-out for why that is worth noticing. Checking several recorded 404s and using Update selected links to the following new URL sets the same destination on all of them at once.

Its parameters are in the Redirect configuration reference.

Redirecting with a menu item

A menu item of type External URL also acts as a redirect. When the requested path matches the menu item's own route exactly, the hub redirects to the item's Link, which may be another page on the hub.

This is worth knowing because it works for paths that belong to a component rather than to an article. To move a group's audience from /groups/mainclass to /groups/spring2016class:

1. Go to Menus → Menu Manager and open a menu that is not displayed anywhere — the Default menu on a stock hub.
2. If the menu has no Groups item, add one: New, then Select next to Menu Item Type, then External URL under System Links. Set Menu Title to Groups and Link to groups. Save & Close.
3. Add a second External URL item with Menu Title Mainclass and Link /groups/spring2016class.
4. Set its Parent Item to Groups, so its route becomes groups/mainclass. Save & Close.

Requests for /groups/mainclass now land on /groups/spring2016class.