Skip to content

Clarify child inheritance #90

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: gh-pages
Choose a base branch
from
Open

Clarify child inheritance #90

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
f623c0b
Clarify what it means for a feature to be enabled or disabled by
clelland Jun 9, 2017
6e90d62
Make it a bit clearer, maybe
clelland Aug 16, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
61 changes: 53 additions & 8 deletions index.bs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,20 @@ spec:fetch; type:dfn; text:value
<li>A <a data-lt="declared policy">declared policy</a>.
</li>
</ul>
<p>The <a>feature policy</a> for a {{Document}} or {{WorkerGlobalScope}}
determines whether a feature is <a>allowed</a> or <a>disallowed</a> in that
context.</p>
<p>A feature which is <dfn>disallowed</dfn> should be disabled, or be made
unavailable for use in the Document or web worker. Each feature may have a
different mechanism for being disabled when <a>disallowed</a>, which should
be defined in that feature's specification.</p>
<p>A feature is <dfn>allowed</dfn> if it is not <a>disallowed</a>.</p>
<p>A feature may be <dfn>allowed by default</dfn> in a {{Document}} or
{{WorkerGlobalScope}}. If a feature is <a>allowed by default</a>, then it
is <a>allowed</a> if no other policy disallows it.</p>
<p>A feature may be <dfn>disallowed by default</dfn> in a {{Document}} or
{{WorkerGlobalScope}}. If a feature is <a>disallowed by default</a>, then it
is <a>disallowed</a> unless explicitly allowed by policy.</p>
</section>
<section>
<h3 id="inherited-policies">Inherited policies</h3>
Expand Down Expand Up @@ -257,16 +271,18 @@ spec:fetch; type:dfn; text:value
allowlists</a>:</p>
<dl>
<dt><code>*</code></dt>
<dd>The feature is allowed at the top level by default, and when allowed,
is allowed by default to documents in child frames.</dd>
<dd>The feature is <a>allowed by default</a> in top-level documents. If
allowed in a frame, the feature is <a>allowed by default</a> in that
frame's children.</dd>
<dt><code>'self'</code></dt>
<dd>The feature is allowed at the top level by default, and when allowed,
is allowed by default to same-origin domain documents in child frames,
but is disallowed by default in cross-origin documents in child
frames.</dd>
<dd>The feature is <a>allowed by default</a> in top-level documents. If
allowed in a frame, the feature is <a>allowed by default</a> in
same-origin documents in child frames, and is <a>disallowed by default</a>
in cross-origin documents in child frames.</dd>
<dt>'none'</dt>
<dd>The feature is disallowed at the top level by default, and is also
disallowed by default to documents in child frames.</dd>
<dd>The feature is <a>disallowed by default</a> in top-level documents,
and is also <a>disallowed by default</a> in documents in child frames.
</dd>
</dl>
</section>
</section>
Expand Down Expand Up @@ -380,6 +396,35 @@ partial interface HTMLIFrameElement {
</section>
</section>
</section>
<section>
<h2 id="combining-policies">Combining Policies from different sources</h2>
<p>To determine the effective feature policy for a given document, several
pieces of information are required:</p>
<ul>
<li>The default allowlists for all features supported by the user agent</li>
<li>The header policy for the document</li>
<li>The origin of the document</li>
</ul>
<p>If the document is in a frame, then this is also required:</p>
<ul>
<li>The feature policy of the document in the parent frame</li>
<li>The container policy defined for the document's frame by its parent.
</li>
</ul>
<p>Then, for each supported feature, we go through these steps:</p>
<ol>
<li>Use the parent's policy and the container policy to define the
<a>inherited policy</a> for the new document.
For each feature, if it is allowed by the parent for the new document's origin,
and not disallowed by the container policy, then it is enabled in the inherited policy. Otherwise, it is disabled.</li>
<li>Use the inherited policy and the document's header policy to determine the
effective policy for the new document.
For each feature, if it is disabled in the inherited policy, then its allowlist will be empty.
If it is enabled, and there is a declaration for that feature in the header policy, then its allowlist will be the declared list from the header.
If it is enabled, and there is no declaration for that feature in the header policy, then its allowlist will be the default allowlist for the feature (with 'self' replaced with the origin of the document).
</li>
</ol>
</section>
<section>
<h2 id="integrations">Integrations</h2>
<p>This document defines a set of algorithms which other specifications will
Expand Down
Loading