The object element

Description

The object element is a reference to a piece of content stored in another file. This may be an image, video, XML text, or other content, but its type must be among those supported by the profile (and possibly features) in use. The optional srctype attribute carries an enumeration of the media types that are allowed.

Two variants of object are defined. The first is for use as an inline element in text; the second is for use in structural contexts (e.g., between paragraphs).

Short Sample

<object xml:id="mnt" src="mouse.png">
 <p>Drawing of a mouse very common on Quail Island.</p>
</object>
        

Possible children

This element may contain text. It may contain the following children: abbr, annotation, caption, code, d, definition, emph, expansion, xforms:input, l, list, m:math, name, noteref, object, pagebreak, param, ssml:phoneme, place, ssml:prosody, quote, xforms:range, ref, its:ruby, ssml:say-as, xforms:secret, sel:select, xforms:select, xforms:select1, span, sub, ssml:sub, sup, term, xforms:textarea, time, ssml:token and w.

Possible parents

annotation, annotation, m:annotation-xml, aside, block, caption, caption, cite, d, definition, emph, expansion, xforms:group, h, hd, hpart, item, item, l, xforms:label, meta, note, object, sel:otherwise, p, ssml:prosody, quote, quote, its:rb, ref, xforms:repeat, its:rt, s, span, td, th and sel:when

Content model

Namespace

http://www.daisy.org/z3986/2010/

This element belongs to the core grammar.

Attributes

Additional Information

Object calls for the incorporation of an external object into the document. It is functionally equivalent to the object element in XHTML 1.1. (TODO add ref)

The required src attribute must contain the URI of the external object. Optional, but recommended, attribute srctype gives the MIME type of the object. (TODO create documentation for this attribute in the attributes list - where does that go?)

Object may contain any number of param children, which provide additional information to the object being included. For instance, if the object is an applet it may require some initialization parameters.

All content of the object element other than param elements is to be used as a fallback if the object itself cannot be displayed. Some types of objects, although legal, may not be supported by the user agent; and some types of objects may not be useful to the person reading the document. For this reason some type of fallback is always required. Three types of fallbacks are allowed:

1. Another nested object, presumably of a different type. For example, the first fallback for an animation may be a static image.
2. Text content. Thus for example a text description can be provided for use when an image object cannot be displayed, or a blind user turns off image display on their device.
3. An annotation can be used instead of a direct fallback.

TODO <ol> above is displaying as a bulleted list - why?

A fallback of type 1 or 2 is used, when necessary, as an automatic and one-to-one replacement for the object, in a manner transparent to the user. Thus, it should contain as closely as possible the same information content as the object itself. In contrast, use of annotation rather than direct fallbacks allows more flexibility and more nuanced semantics:

• More than one annotation can be attached to an object, or a single annotation can stand in for several objects.
• Annotations are meant to be shown or hidden at the user's option.
• The annotation's role attribute can express a more nuanced semantics than simple replacement.

For example, a republisher might use a paragraph of text to summarize the meaning of a graph rather than translating all the data in a graph into text:

            <object xml:id="g1" src="graph.svg"/>
            <annotation for="g1" role="summary republisherAnno">
                This graph shows...
            </annotation>
          

TODO: summary role not in schema

Only objects of types legal in the current profile may be used. However, the Arbitrary Object Inclusion feature (TODO is this the correct name?) allows inclusion of any object type. Providing a fallback that is a profile-approved type is in this case recommended, and an ultimate fallback of included or annotating text is still required.