6 The DESCRIPTION file
The DESCRIPTION
file must be properly formatted.
The following sections will review some important notes regarding fields of the
DESCRIPTION
file and associated files.
6.1 Package
This is the name of the package. The repository name and the name of the Package in the description should match (including case-sensitive).
6.3 Version
All Bioconductor packages use an x.y.z
version scheme.
See Version Numbering for specifics to how the release
and devel Bioconductor versioning proceeds. When
first submitted to Bioconductor, a package should have pre-release version
0.99.0
.
The following rules apply:
-
x
is usually 0 for packages that have not yet been released. -
y
is even for packages in release, and odd for packages in devel. Generally, do not bump this number especially in pre-release. -
z
is incremented whenever committing changes to a package.
6.4 Description
The description should be a relatively short but detailed overview of what the package functionality entails. It should be at least three complete sentences.
6.6 License
The license field should preferably refer to a standard license (see wikipedia) using one of ’s standard specifications. ships with the following standard licenses
Be specific about any version that applies (e.g., GPL-2
).
Licenses restricting use, e.g., to academic or non-profit researchers, are not
suitable for Bioconductor. Core Bioconductor packages are typically
licensed under Artistic-2.0
.
To specify a non-standard license, include a file named LICENSE
in your
package (containing the full terms of your license) and use the string file LICENSE
in this License:
field.
The package should contain only code that can be redistributed according to the package license. Be aware of the licensing agreements for packages you are depending on in your package. Not all packages are open source even if they are publicly available.
6.7 LazyData
For packages that include data, we recommend not including LazyData: TRUE
.
In our experience it only slows down the loading of packages with large
data. There are of course exceptions; please provide reasoning if included.
6.8 Depends
, Imports
, Suggests
, Enhances
All packages must be available via Bioconductor’s biocViews or
CRAN; the use of the Remotes:
field is not supported, hence dependencies only
available on other repositories (e.g. GitHub) are
not allowed nor is specify an explicit version of a package.
Reuse, rather than re-implement or duplicate, well-tested functionality from other packages. Make use of appropriate existing packages (e.g., biomaRt, AnnotationDbi, Biostrings, etc.) and classes (e.g., SummarizedExperiment, GenomicRanges::GRanges, S4Vectors::Rle, Biostrings::DNAStringSet, etc.), and avoid duplication of functionality available in other Bioconductor packages. See Common Bioconductor Methods and Classes. Bioconductor reviewers are very strict on this point! New packages should be interoperable with existing Bioconductor classes and should not reimplement functionality especially with regards to importing/reading data.
A package can be listed only once between Depends:
, Imports:
, Suggests:
,
or Enhances:
. Determine placement of package based on the following
guidelines:
Imports:
is for packages that provide functions, methods, or classes that are used inside your package name space. Most packages are listed here.Depends:
is for packages that provide essential functionality for users of your package, e.g., theGenomicRanges
package is listed in theDepends:
field ofGenomicAlignments
. It is unusual for more than three packages to be listed asDepends:
.-
Suggests:
is for packages used in vignettes, examples, and in conditional code.Commonly, annotation and experiment packages (e.g.,TxDb*
) used in vignette and example code are included in this field thus avoiding a costly download. In the case where an external one-off function is required for package code, the package availability and usage can be done via: Enhances:
is for packages such asRmpi
orparallel
that enhance the performance of your package, but are not strictly needed for its functionality.
It is seldom necessary to specify or specific versions as dependencies, since the Bioconductor release strategy and standard installation instructions guarantee these constraints. Repositories mirrored outside Bioconductor should include branches for each Bioconductor release, and may find it useful to fully specify versions to enforce constraints otherwise guaranteed by Bioconductor installation practices.
For additional information regarding Depends, Imports, Suggest and where a package should be placed see Connecting to other packages and the package dependency section of Writing R Extensions.
6.9 SystemRequirements
This field is for listing any external software which is required, but not automatically installed by the normal package installation process.
If the installation process is non-trivial, a top-level INSTALL
file should
be included to document the process. If a user facing README
is included it
is also recommended to document the process there; do not try to install a
dependency for a user anywhere in the package (i.e. readme, r code, man pages,
vignette). You may show instructions only in unevaluated sections. See also
Additional files and dependencies
6.10 biocViews
This field is required!
Specify at least two leaf node from biocViews.
Multiple leaf terms are encouraged but terms must come from the same trunk or
package type (i.e., Software
, AnnotationData
, ExperimentData
, or
Workflow
). biocViews
terms are case-sensitive.
The field name “biocViews” is case-sensitive and must begin with a lower-case ‘b’. Please use a single line with biocViews seperated by commas
(i.e,biocViews: GeneTarget, SingleCell
).
6.12 URL
This field directs users to source code repositories, additional help
resources, etc; details are provided in the Writing R Extensions
manual, RShowDoc("R-exts")
.