Length
RIXML 2.5 Element
Optional element indicating the size or duration of the payload file with required lengthUnit attribute specifying measurement type (pages for PDFs, time units for audio/video).
Indicates the length of the product. For example, if the product were a PDF file, the length would be in pages.
Usage
Optional element within Resource, appearing at most once. When present, must include lengthUnit attribute specifying measurement type. Contains numeric value.
Business Context
Helps research consumers estimate download times and storage requirements, supporting informed content access decisions in research distribution workflows.
Specification Guide
Overview
Length specifies the size or duration of a research Resource's payload, expressed as a numeric value whose unit of measure is given by the required lengthUnit attribute (drawn from LengthUnitEnum). Typical uses are page counts for PDF documents and time durations for audio or video content. By exposing length up front, RIXML helps downstream systems and end users estimate consumption time, storage needs, and bandwidth requirements before a resource is opened or downloaded.
Usage
Length appears as an optional child of Resource (within Content) and may occur at most once per Resource in RIXML 2.x (sources: level-one-2.2 p.16, level-one-2.3.1 p.11, level-one-2.5 p.11). When present, lengthUnit is required so the numeric content can be unambiguously interpreted — for example Pages for written documents or TimeUnit for audio/video (sources: user-guide-2.3 p.49, data-dictionary-2.5.1 p.69).
Publishers should populate Length whenever a meaningful measurement is available, particularly for PDF deliverables and media files, since it materially improves the consumer experience by signalling reading time or playback duration. Conversely, Length should be omitted for content types where a single size measurement is not meaningful — for example interactive models or data tools [v3-enumlist-set1-publishing p.8].
In the RIXML v3 draft, Length is described as a required string element when length information is provided within the resource container, still paired with lengthUnit [data-dictionary-v3-draft p.19].
Rules
- MUSTWhen Length is included, the lengthUnit attribute must be supplied to specify the measurement type (e.g.
Pages,TimeUnit).[RIXML Level One Addendum v2.2 p.16] [RIXML Level One Addendum v2.3 p.11] [RIXML Level One Addendum v2.3.1 p.11] [RIXML Level One Addendum v2.5 p.11] [RIXML Research Data Dictionary v2.5.1 p.69] - SHOULDLength should be omitted when a length measurement is not meaningful for the content, such as for models or interactive resources.[RIXML v3 Enum Set 1: Publishing Content and Framing p.8]↗
- MUSTWithin a single Resource, Length may appear at most once.[RIXML Level One Addendum v2.2 p.16] [RIXML Level One Addendum v2.3.1 p.11] [RIXML Level One Addendum v2.5 p.11]
Relationships
- child-ofResource — Length is an optional child of Resource within the Content package, providing size or duration metadata for the resource's payload.
- requiresLength.lengthUnit — Length requires the lengthUnit attribute to qualify the numeric value with a unit of measure from LengthUnitEnum.
- usesLengthUnitEnum — The unit value carried by lengthUnit is drawn from LengthUnitEnum (e.g.
Pages,TimeUnit).
Where It Fits
Definition
| Type | |
| Namespace | http://www.rixml.org/2017/9/RIXML |
| Min Occurs | 1 |
| Max Occurs | 1 |
| Content Model | Text content (string) |
Attributes
lengthUnitLengthUnitEnum |
Indicates the unit of length. For example pages, seconds, minutes. requiredSince 2.1 |
Children
Contains text content (type: string)
This element's value is its text content. Attributes provide additional context.
Example
<Length lengthUnit="Value">ABC-123</Length>Version History
Unchanged since introduction in RIXML 2.1
Length is present in the Utility/Content package across RIXML 2.1 through 2.5 as an optional, single-occurrence child of Resource, always paired with a required lengthUnit attribute (sources: user-guide-2.1 p.46, user-guide-2.2 p.48, user-guide-2.3 p.49, user-guide-2.3.1 p.49, data-dictionary-2.4 p.66, data-dictionary-2.5.1 p.69). Its semantics and structure remained stable across these versions, with documentation consistently illustrating Pages for PDFs and time-based units for audio/video.
In the RIXML v3 draft, Length is repositioned within a ResourceList container and described as a required string element when length information is provided, still qualified by lengthUnit [data-dictionary-v3-draft p.19]. The v3 enumeration guidance also introduces explicit advice to omit Length for content types where it is not meaningful, such as models and interactive resources [v3-enumlist-set1-publishing p.8].
Business Rules
When Length element is included, the lengthUnit attribute is required
Semantic Relationships
Requires1 relationship
When a Length element is included, the lengthUnit attribute is required to indicate which measure is being used
RIXML Level One Addendum v2.5, p.11— Research.Product.Content.Resource.Length