# `MishkaCmsCore.Runtime.Resources.Validations.SiteScopedDocument`
[🔗](https://github.com/mishka-group/mishka_cms_core/blob/v0.0.1/lib/mishka_cms_core/runtime/resources/__validations/site_scoped_document.ex#L5)

Refuses a global row about a document that cannot itself be global.

## What it is for

`MishkaCmsCore.Runtime.PageComment` is `global? true`, because the builder edits documents that
are global — components and layouts — as well as documents that are not. But the two `global?
false` documents, **pages** and **error pages**, always belong to exactly one site, so a note
about one has no honest reading as "belongs to no site". Left unguarded, such a row is visible to
every tenant on every site, which is the opposite of what a page note means.

It was true in practice already, by accident: the builder happens to hand a master the record's
own `site_id`. That is a LiveView doing the right thing, not a rule — and a JSON:API caller, a
seed, or a future screen would not know to. This makes it a rule.

## Options

  * `:sections` — the section values that require a site. Required.
  * `:attribute` — where the section is stored. Defaults to `:section`.

## Usage

    create :master_create do
      validate {SiteScopedDocument, sections: [:page, :error_page]}
    end

A section not in the list is left alone: a note on a component may be global, and a tenant's note
on that same component is stamped with their own site by the tenant action, not by this.

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*Consult [api-reference.md](api-reference.md) for complete listing*