DITA maps have unique attributes that are designed to control the way that relationships are interpreted for different output purposes. In addition, DITA maps share many metadata and linking attributes with DITA topics.
DITA maps often encode structures that are specific to a particular medium or output, for example, Web pages or a PDF document. Attributes, such as deliveryTarget and toc, are designed to help processors interpret the DITA map for each kind of output. Many of these attributes are not available in DITA topics; individual topics, once separated from the high-level structures and dependencies associated with a particular kind of output, should be entirely reusable regardless of the intended output format.
- The collection-type attribute specifies how the children of a topicref element relate to their parent and to each other. This attribute, which is set on the parent element, typically is used by processors to determine how to generate navigation links in the rendered topics. For example, a collection-type value of "sequence" indicates that children of the specifying topicref element represent an ordered sequence of topics; processors might add numbers to the list of child topics or generate next/previous links for online presentation. This attribute is available in topics on the linklist and linkpool elements, where it has the same behavior. Where the collection-type attribute is available on elements that cannot directly contain elements (such as reltable or topicref), the behavior of the attribute is reserved for future use.
By default, the relationships between the topics that are referenced in a map are reciprocal:
- Child topics link to parent topics and vice versa.
- Next and previous topics in a sequence link to each other.
- Topics in a family link to their sibling topics.
- Topics referenced in the table cells of the same row in a relationship table link to each other. A topic referenced within a table cell does not (by default) link to other topics referenced in the same table cell.
This behavior can be modified by using the linking attribute, which enables an author or information architect to specify how a topic should participate in a relationship. The following values are valid:
- Specifies that the topic does not exist in the map for the purposes of calculating links.
- Specifies that the topic will link to its related topics but not vice versa.
- Specifies that the related topics will link to it but not vice versa.
- Default value. It specifies that linking will be reciprocal (the topic will link to related topics, and they will link back to it).
Authors also can create links directly in a topic by using the xref or link elements, but in most cases map-based linking is preferable, because links in topics create dependencies between topics that can hinder reuse.
Note that while the relationships between the topics that are referenced in a map are reciprocal, the relationships merely imply reciprocal links in generated output that includes links. The rendered navigation links are a function of the presentation style that is determined by the processor.
- Specifies whether topics are excluded from navigation output, such as a Web site map or an online table of contents. By default, topicref hierarchies are included in navigation output; relationship tables are excluded.
- Specifies a navigation title. This is a shorter version of the title that is
used in the navigation only. By default, the navtitle
attribute is ignored; it serves only to help the DITA map author keep track
of the title of the topic. Note: The navtitle attribute is deprecated in favor of the navtitle element. When both a navtitle element and a navtitle attribute are specified, the navtitle element should be used.
If locktitle is set to "yes", the navtitle element or navtitle attribute is used if it is present. Otherwise, the navtitle element or navtitle attribute is ignored and the navigation title is retrieved from the referenced file.Note: The navtitle attribute is deprecated in favor of the navtitle element. When both a navtitle element and a navtitle attribute are specified, the navtitle element should be used.
- Specifies whether the topic should be included in printed output.
Note: Beginning with DITA 1.3, the print attribute is deprecated. It is replaced with a conditional processing attribute: deliveryTarget. See deliveryTarget for more details.
- Specifies whether the topic should be included in search indexes.
- Specifies that the processor generates an interim set of DITA topics that
are used as the input for the final processing. This can produce the
following output results:
- Multi-topic files are transformed into smaller files, for example, individual HTML files for each DITA topic.
- Individual DITA topics are combined into a single file.
Specifying a value for the chunk attribute on a map element establishes chunking behavior that applies to the entire map, unless overridden by chunk attributes that are set on more specific elements in the DITA map. For a detailed description of the chunk attribute and its usage, see Chunking.
In most situations, specifies whether a duplicate version of the topic is created when it is transformed. This duplicate version can be either literal or virtual. The value of the copy-to attribute specifies the uniform resource identifier (URI) by which the topic can be referenced by a conref attribute, topicref element, or xref element. The duplication is a convenience for output processors that use the URI of the topic to generate the base address of the output. The keys and keyref attributes provide an alternative mechanism; they enable references to topics in specific-use contexts.
The copy-to attribute also can be used to specify the name of a new chunk when topics are being chunked; it also can be used to determine the name of the stub topic that is generated from a topicref element that contains a title but does not specify a target. In both of those cases, no duplicate version of the topic is generated.
For information on how the copy-to attribute can be used with the chunk attribute, see Chunking.
- Specifies whether the topic or map referenced should be processed normally
or treated as a resource that is only included in order to resolve key or
- The topic is a readable part of the information set. It is included in navigation and search results. This is the default value for the topicref element.
- The topic should be used only as a resource for processing. It is not included in navigation or search results, nor is it rendered as a topic. This is the default value for the keydef element.
If the processing-role attribute is not specified locally, the value cascades from the closest element in the containment hierarchy.
- Specifies whether the default rules for the cascading of metadata attributes in a DITA map
apply. In addition to the following specified values, processors also MAY define additional
- The metadata attributes cascade; the values of the metadata attributes are additive. This is the processing default for the cascade attribute and was the only defined behavior for DITA 1.2 and earlier.
- The metadata attributes cascade; however, they are not additive for topicref elements that specify a different value for a specific metadata attribute. If the cascading value for an attribute is already merged based on multiple ancestor elements, that merged value continues to cascade until a new value is encountered (that is, setting cascade="nomerge" does not undo merging that took place on ancestors).
For more information, see Example: How the cascade attribute functions.
- Specifies one or more key names.
- Defines a new scope for key definition and resolution, and gives the scope one or more names. For more information about key scopes, see Indirect key-based addressing.