WIP on map-extent, updates to layer

Author: prushforth

spec/index.html

@@ -341,6 +341,7 @@ <h3>Changes</h3>
               <li><time>2023-06-08</time>: Add initial draft WebIDL for <code>geojson2mapml</code>(). Add prose for <code>back</code>, <code>forward</code>, <code>reload</code>.
               <li><time>2023-06-12</time>: Add <code>HTMLGeometryChildElement</code> abstract interface
               <li><time>2023-06-29</time>: Update Authoring section. Include definitions of local and remote content.
+              <li><time>2023-11-05</time>: Correct error in contexts in which <code>map-extent</code> is found. Add opacity attribute to layer.  
             </ol>
           </details>
         </section>
@@ -873,6 +874,7 @@ <h4>The <code>&lt;<dfn id="the-layer-element">layer</dfn>&gt;</code> element</h4
           if the layer is not not <a href="#attr-layer-hidden"><code>hidden</code></a>. The map author's <a href="#the-title-element"><code>title</code></a> element takes precedence over <code>label</code>, if available.</dd>
         <dd id="attr-layer-checked"><code>checked</code> — Turn the layer on/off dynamically on the map. </dd>
         <dd id="attr-layer-hidden"><code>hidden</code> — Visibility status of the layer in the layer control. Does not affect visibility of the layer on the map.</dd>
+        <dd id="attr-layer-opacity"><code>opacity</code> — An initial opacity value which is reflected to the exposed user interface in the layer control for opacity. Opacity values have a decimal range from 0 (transparent) to 1.0 (opaque)</dd>
         <dd id="attr-layer-referrerpolicy"><code>referrerpolicy</code> — <a href="https://w3c.github.io/webappsec-referrer-policy/#referrer-policy">Referrer policy</a> for <a href="https://fetch.spec.whatwg.org/#concept-fetch">fetches</a> initiated by the element.</dd>
         <dd id="attr-layer-crossorigin"><code>crossorigin</code> — A <a href="https://html.spec.whatwg.org/multipage/urls-and-fetching.html#cors-settings-attribute">CORS settings attribute</a>, specifies how the element handles crossorigin requests.</dd>
         <dt><a href="https://html.spec.whatwg.org/multipage/dom.html#concept-element-tag-omission">Tag omission in text/html</a>:</dt>
@@ -2155,7 +2157,7 @@ <h5>The <code>&lt;<dfn id="the-extent-element">extent</dfn>&gt;</code> element</
           <dt><a href="https://html.spec.whatwg.org/multipage/dom.html#concept-element-categories">Categories</a>:</dt>
           <dd><a href="https://html.spec.whatwg.org/multipage/dom.html#metadata-content-2">Metadata content</a>.</dd>
           <dt><a href="https://html.spec.whatwg.org/multipage/dom.html#concept-element-contexts">Contexts in which this element can be used</a>:</dt>
-          <dd>In <a href="#dfn-remote-content">remote content</a>, as a child of the <a href="#the-head-element"><code>head</code></a> element.</dd>
+          <dd>In <a href="#dfn-remote-content">remote content</a>, as a child of the <a href="#the-body-element"><code>body</code></a> element.</dd>
           <dd>In <a href="#dfn-local-content">local content</a>, as a child of the <a href="#the-layer-element"><code>layer</code></a> element.</dd>
           <dt><a href="https://html.spec.whatwg.org/multipage/dom.html#concept-element-content-model">Content model</a>:</dt>
           <dd>
@@ -2164,10 +2166,11 @@ <h5>The <code>&lt;<dfn id="the-extent-element">extent</dfn>&gt;</code> element</
           </dd>
 
           <dt><a href="https://html.spec.whatwg.org/multipage/dom.html#concept-element-attributes">Content attributes</a>:</dt>
-          <dd><code>units</code> — The name of the coordinate reference system whose measurement units are to be used by values supplied by child <a href="#the-input-element"><code>input</code></a> elements.</dd>
-          <dd><code>label</code> — A text label to be applied to the user interface for the <a href="#the-extent-element"><code>extent</code></a> in the layer control. If no label is supplied, the <a href="#the-extent-element"><code>extent</code></a> will not expose a user interface in the layer control, but will still be displayed on the map.</dd>
-          <dd><code>opacity</code> — An initial opacity value, that will be applied to the content retrieved by the <a href="#the-extent-element"><code>extent</code></a>, and which is reflected to the exposed user interface for opacity. Opacity values have a decimal range from 0 (transparent) to 1.0 (opaque).</dd>
-          <dd><code>checked</code> — A boolean attribute that sets the initial state of the exposed user interface in the layer control. If checked, the <a href="#the-extent-element"><code>extent</code></a> content is displayed on the map.</dd>
+          <dd id="attr-extent-units"><code>units</code> — The name of the coordinate reference system whose measurement units are to be used by values supplied by child <a href="#the-input-element"><code>input</code></a> elements.</dd>
+          <dd id="attr-extent-label"><code>label</code> — A text label to be applied to the user interface for the <a href="#the-extent-element"><code>extent</code></a> in the layer control. If no label is supplied, a default value will be generated for non-hidden extents, with the intended meaning of "Sub-layer".</dd>
+          <dd id="attr-extent-opacity"><code>opacity</code> — An initial opacity value, that will be applied to the content retrieved by the <a href="#the-extent-element"><code>extent</code></a>, and which is reflected to the exposed layer control user interface for opacity. Opacity values have a decimal range from 0 (transparent) to 1.0 (opaque).</dd>
+          <dd id="attr-extent-checked"><code>checked</code> — A boolean attribute that sets the initial state of the exposed user interface in the layer control. If checked, the <a href="#the-extent-element"><code>extent</code></a> content is rendered on the map.</dd>
+          <dd id="attr-extent-hidden"><code>hidden</code> — Visibility status of the extent in the layer control. Does not affect visibility of the extent on the map.</dd>
           <dt><a href="https://html.spec.whatwg.org/multipage/dom.html#concept-element-accessibility-considerations">Accessibility considerations</a>:</dt>
           <dd>
             <details class="a11y-details">