RDF ContainersElements
RDF containers are used to describe a group of things. For example, listing the authors of a book together.
The following RDF elements are used to describe these groups: <Bag>, <Seq>, and <Alt>.
<rdf:Bag> Element
The <rdf:Bag> element is used to describe a list of values that is specified as unordered.
The <rdf:Bag> element may contain duplicate values.
Example
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:cd="http://www.recshop.fake/cd#">
<rdf:Description
rdf:about="http://www.recshop.fake/cd/Beatles">
<cd:artist>
<rdf:Bag>
<rdf:li>John</rdf:li>
<rdf:li>Paul</rdf:li>
<rdf:li>George</rdf:li>
<rdf:li>Ringo</rdf:li>
</rdf:Bag>
</cd:artist>
</rdf:Description>
</rdf:RDF>
<rdf:Seq> Element
The <rdf:Seq> element is used to describe a list of values that is specified as ordered (such as an alphabetical sort).
The <rdf:Bag> element may contain duplicate values.
Example
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:cd="http://www.recshop.fake/cd#">
<rdf:Description
rdf:about="http://www.recshop.fake/cd/Beatles">
<cd:artist>
<rdf:Seq>
<rdf:li>George</rdf:li>
<rdf:li>John</rdf:li>
<rdf:li>Paul</rdf:li>
<rdf:li>Ringo</rdf:li>
</rdf:Seq>
</cd:artist>
</rdf:Description>
</rdf:RDF>
<rdf:Alt> Element
The <rdf:Alt> element is used for a list of alternative values (the user may select only one of these values).
Example
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:cd="http://www.recshop.fake/cd#">
<rdf:Descriptio
rdf:about="http://www.recshop.fake/cd/Beatles">
<cd:format>
<rdf:Alt>
<rdf:li>CD</rdf:li>
<rdf:li>Record</rdf:li>
<rdf:li>Tape</rdf:li>
</rdf:Alt>
</cd:format>
</rdf:Descriptio>
</rdf:RDF>
RDF Terminology
In the examples above, we have discussed "lists of values" when describing container elements. In RDF, these "lists of values" are called members.
Therefore, we can say:
- A container is a resource that contains things
- The contained things are called members (not "lists of values").