Set Up URL Redirects with page-aliases

Page aliases are designed to address page renames or moves, particularly within a component version. They are not a general-purpose URL router. Although they can be used to create redirects across components or component versions, you need to use this feature with care or else it can become quite noisy and thus confusing.

If you remove a large number of pages, such as if you remove or rename a component or component version, and you want to preserve the existing URLs, you should not attempt to do so using page aliases. Page aliases were not designed to provide bulk URL redirects. Instead, we strongly recommended that you use the router provided by your web server or host when you remove or rename a component or component version. You can do so either using a separate step during publishing or by using an Antora extension.

The page-aliases attribute is set in the page header of a target page using an attribute entry. The target page refers to the page you’re redirecting a source page to. The source page refers to the deleted, renamed, or moved page that you’re redirecting from (i.e., the page to claim). A source page’s resource ID—​its resource ID before it was deleted, renamed, or moved—​is assigned to the page-aliases attribute in a target page. Multiple resource IDs can be assigned to the attribute in a comma-separated list.

You can split this list across multiple lines using a line continuation (a space followed by a backslash at the end of the line):

Antora calculates the URL for a source page’s resource ID and generates redirect information so that the source page URL redirects to the target page URL. Any coordinates, such as version or component, that aren’t specified in a resource ID assigned to page-aliases are interpolated from the target page’s coordinates. The generated output format of the redirect information is determined by your chosen redirect facility.

A resource ID assigned to a page-aliases attribute can be used in an xref. Therefore, if you delete, rename, or move a page, you don’t need to update any references to it in your source files.

If you change a source page’s filename from old-name.adoc to new-name.adoc, assign the file’s former resource ID to page-aliases in its header.

This will result in https://base-url.com/component/version/module/old-name.html being redirected to https://base-url.com/component/version/module/new-name.html. The version, component, and module coordinates that weren’t specified in the old-name.adoc resource ID are interpolated from the target page’s coordinates. Alternatively, if you assigned indexify to the html-extension-style key in your playbook, https://base-url.com/component/version/module/old-name/ will redirect to https://base-url.com/component/version/module/new-name/ .

When a page is moved from one module to another module in the same component, the aliased resource ID needs to contain the source page’s former module coordinate. In Example 4, the page source-1.adoc has moved from module-1 to module-z. Both module-1 and module-z are modules in version 5.0 of component-1.

Now, Antora will redirect the URL https://base-url.com/component-1/5.0/module-1/source-1.html to the URL https://base-url.com/component-1/5.0/module-z/source-1.html.

When a page is moved from one component to another component, assign the source page’s fully qualified former resource ID to page-aliases. In Example 5, the page source-w.adoc has moved from version 1.4 of component-8, module-u to version 3.0 of component-delta, ROOT.

This will result in the URL https://base-url.com/component-8/1.4/module-u/source-w.html being redirected to https://base-url.com/component-delta/3.0/source-w.html.

Sometimes you just need to delete a page. Before redirecting the deleted page’s URL to another page, consider the following:

You shouldn’t create a redirect to a target page that doesn’t have much in common with the deleted page, as this often frustrates visitors.

If it’s appropriate to redirect the deleted page’s URL to another page, assign the deleted page’s ID to the page-aliases attribute, making sure to specify the necessary coordinates.