Duplication

Edit a block once, for example the site footer, and have it copied, verbatim, onto every page that references it. One master, many copies, kept in step on every run.

<!-- sitehoster:duplicate name="footer" role="master"
     NOTE: Master copy of the site footer — edit here.
     See: https://sitehoster.org/usage/automation/duplication/ -->
<footer>
  … your footer …
</footer>
<!-- sitehoster:/duplicate name="footer" -->

The master: the one copy you edit.

Attributes

A duplication is a paired block, an opening sitehoster:duplicate comment and a matching close, wrapped around the content. Its role is set on the opening comment, and a free-text note after it reminds editors what the block is:

Name	Type	Description
`name`	required	ties a master to its copies; use different names for independent blocks (a footer, a banner, a sign-up box)
`role`	`master` or `copy`	whether this block is the source you edit or a generated copy

Note: the notes are free text to remind editors about the structure.

Copies

On every other page, the same markers with role="copy". Whatever sits between them is replaced with the master’s content on the next run, and the note points back to where the master lives:

<!-- sitehoster:duplicate name="footer" role="copy"
     NOTE: Generated — edit the master at: /index.html
     See: https://sitehoster.org/usage/automation/duplication/ -->
<footer>
  … replaced from the master …
</footer>
<!-- sitehoster:/duplicate name="footer" -->

A copy: its content is replaced from the master.

There must be exactly one master per name within a site or group, and a copy with no master is an error. In a group a master and its copies are shared across every member: define the block once, on any site, and it fills the copies on all of them.

Propagate the master to every copy with node client/automate.js (add --dry-run -v to preview).

Errors

A duplication is validated before the site is written; a problem is reported against the page and the block, and the site is left unchanged until it is fixed (other sites still run):

Message	When it appears
`sitehoster:duplicate "…" must set role="master" or role="copy"`	an opening `duplicate` with no `role`, or an unknown one
`a second master for duplicate "…" (already defined in …)`	two masters share one `name` within a site or group
`copy duplicate "…" has no master in group "…"`	a `role="copy"` block whose `name` has no master anywhere in the group