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This section is informative. For the normative version, see [XHTML2].
The Embedding Attributes module defines the Embedding attribute collection.
This collection causes the contents of a remote resource to be embedded in the document in place of the element's content. If accessing the remote resource fails, for whatever reason (e.g., network unavailable, no resource available at the URI given, inability of the user agent to process the type of resource) or an associated @ismap attribute fails, the content of the element must be processed instead.
Note that this behavior makes documents far more robust, and gives much better opportunities for accessible documents than the longdesc
attribute present in earlier versions of XHTML, since it allows the description of the resource to be included in the document itself, rather than in a separate document.
Example
<p src="holiday.png" srctype="image/png"> <span src="holiday.gif" srctype="image/gif"> An image of us on holiday. </span> </p> <table src="temperature-graph.png" srctype="image/png"> <caption>Average monthly temperature over the last 20 years</caption> <tr><th>Jan</th><th>Feb</th><th>Mar</th><th>Apr</th><th>May</th><th>Jun</th> <th>Jul</th><th>Aug</th><th>Sep</th><th>Oct</th><th>Nov</th><th>Dec</th> </tr> <tr><td> 4</td><td> 2</td><td> 7</td><td> 9</td><td>13</td><td>16</td> <td>17</td><td>17</td><td>14</td><td>11</td><td> 7</td><td> 4</td> </tr> </table>
The user agent must use this list as the field value of the accept-charset
request header when requesting the resource using HTTP.
If this attribute is not present, the user agent must use its default value of the accept-charset request header.
User agents should use a similar technique when using other protocols that allow encoding negotation
When using protocols that do not allow encoding negotiation to retrieve resources whose encodings are not self-identifying, the user agent should use the first encoding in the attribute's value as the indication of the resource.
Example
<style type="text/css" src="style/home" encoding="utf-8" />
What happens if the src fails
If the src attribute target is not available, the contents of the element are processed. Is there a DOM event that is raised in this context as well?
At the Dulles f2f we discussed the possibility of relying upon DOM events to raise these - but ensure that XHTML refers to DOM events for any elements / attributes that have behaviors in addition to semantics.
This attribute specifies the allowable content types of the resource referenced by the relevant @src URI.
Example
<handler src="pop" srctype="application/x-javascript, text/x-newspeak" /> <style src="midnight" srctype="text/css, text/x-mystyle" /> <p src="w3c-logo" srctype="image/png, image/jpeg;q=0.2">W3C logo</p> <span src="logo.png">Our logo</span> <span src="theme.mp3" srctype="audio/x-mpeg">Our theme jingle</span>
When this module is selected, the Embedding Attribute Collection is included in the Common attribute collection.
Implementations: RELAX NG, XML Schema
Re: Formal Response to My issue on styling embedding attributes.
PR #7724
State: Open
Resolution: None
User: None
Notes:
Original message at:
http://lists.w3.org/Archives/Public/www-html-editor/2005AprJun/0064
This is a reply to issue 7655, where SP also replied
17 Embedding Attributes User aborted downloads.
PR #7730
State: Approved
Resolution: Accepted
User: None
Notes:
Any failure to completely process the reference results in falling back. User
abort is also such a failure. We will ensure that the definition of the
embedding attributes is clear about this.
17 Embedding Attributes - Invalid XHTML 2 documents
PR #7731
State: Approved
Resolution: Modify and Accept
User: None
Notes:
The working group believes that if a resource is successfully accessed, the
fallback is NOT accessed even if the resource cannot be appropriately rendered
by the user agent. We will ensure the specification makes this clear.
Moreover, things brought in via the src attribute are in an independent context
- just as in the object element.
[XHTML 2] 17.1 Encoding attribute
PR #7732
State: Approved
Resolution: Reject
User: None
Notes:
The encoding applies to retrieving a specific version of a resource to hand off
to a resource processor for an embedded attribute. It has nothing to do, per
se, with the capabilities of the user agent. We will make it clear in the text
that this is the case.
[XHTML 2] Embedding attributes and nextFocus
PR #7733
State: Approved
Resolution: Modify and Accept
User: None
Notes:
Embedded content is not in the document flow, so it is not availabnle for use in
nextfocus. We will clarify this.
17 Embedding Attributes Success/Failure status codes.
PR #7734
State: Approved
Resolution: Modify and Accept
User: None
Notes:
This specification should not specify anything about how the underlying
protocols associated with a URI scheme report success or failure. We will
clarify in the spec that this is the responsibility of the associated protocol.
[XHTML 2] 17 Embedding Attributes - srcType
PR #7735
State: Approved
Resolution: None
User: None
Notes:
Add note to section that effect is defined in the datatype definition.
[XHTML 2] Embedding XHTML Resources Linking.
PR #7736
State: Approved
Resolution: Modify and Accept
User: None
Notes:
Content brought in via the src attribute is placed *within* the surrounding
element, so any annotation on the surrounding element would apply to that
element. In this case, the href attribute would make the surrounding element
(the a) linkable. We will clarify this in the specification.
[XHTML 2] Embedded Resources containing links
PR #7737
State: Approved
Resolution: Modify and Accept
User: None
Notes:
Embedded content is in an independent context, so any links within that content
would replace the embedded content, and not effect the surrounding document. We
will examine providing functionality to embed content inline in a specification
separately.
[XHTML 2] Embedding Attributes Examples
PR #7738
State: Approved
Resolution: Reject
User: None
Notes:
The purpose of this example is to demonstrate that it is possible to use src on
tables. While it might be more sensible to embed the table within an img
element, it would not achieve the same result in the example.
[XHTML 2] 17 Clipping of embedded documents to viewport.
PR #7739
State: Approved
Resolution: Accepted
User: None
Notes:
The embedded resource is in its own context and has its own environment (e.g.,
object or iframe) and any styling would be relative to that environment.
[XHTML 2] 17 Embedding Attributes
PR #7774
State: Approved
Resolution: Accepted
User: None
Notes:
We will provide additional use cases and examples.
xhtml2 attributes type, srctype and hreftype
PR #7892
State: Approved
Resolution: Accepted
User: None
Notes:
We will add srclang. All the embedding attributes should be equivalent to the
linking attributes. We will also ensure that @type is used consistently.