NEWS

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projectData 0.1.0

• Initial CRAN release.
• Register installed R data packages as named collections.
• Provide deferred access and metadata-only resource inventories.
• Support explicit name-conflict resolution and source-qualified access.
• Preserve package provenance and installation identity.
• Introduce a public loader interface for specialized data formats.
• Fixed removal of temporary staging links on Windows (junctions and directory symbolic links), and made link-ownership checks compare locations rather than path text.
• Tests and the adapters vignette no longer assume directory-link creation succeeds: environments without link support (e.g. some CRAN Windows builds) now exercise the documented projectData_staging_error path instead of failing, and the vignette's executable source-tree-authoring example uses a portable installed-layout directory that needs no links.

Changes in this version

• Changed installations are now detected reliably. The registered installation is compared with the metadata on disk at its recorded root (never a loaded namespace), and the library entry must still lead to that root. Previously a library link repointed to another installation (pak/renv-style stores) left the physically resolved root untouched, so data_attach() was a silent no-op and bindings stayed stale. The identity also covers every file in Meta/ and the manifest, so same-version reinstalls are caught without relying on one timestamp.
• The stale-installation error names the collection, path, registered and current version and the exact data_attach(..., replace = TRUE) command, and states that objects already held elsewhere keep the old value. It is raised before registration, bindings, preferences or attachment change.
• data_attach(replace = TRUE) for an existing id keeps omitted lib.loc (the library of the current installation, not .libPaths()), suffix and include; explicit arguments win. A failed replacement keeps the previous state (class projectData_replace_failed). Old resource records and caches are discarded whenever the installation changed. A lib.loc that selects a different installation for an existing id now fails with projectData_installation_conflict (and with the stale-installation error if the registered one changed) unless replace = TRUE.
• Resource working directories (for loaders that need a writable copy) are now built from safe path components. Both the collection id and the resource name are encoded injectively (only a-z, 0-9 and - pass through; every other byte, including uppercase letters, becomes %XX), so path separators or .. can no longer move a directory out of projectData-work, and distinct identities such as a/b and a_b never share a directory. Directory names for ids or resources containing uppercase letters, _ or . differ from earlier versions. Caching, directory reuse and lifetime are unchanged; existing directories are never deleted.

projectData 0.0.0.9006

Changes in this version

• Manifest validation and authoring against a verified package source tree now accept Source paths that pass through a symbolic link under inst/ (e.g. inst/extdata -> /shared/data), provided the final path exists. Source stays package-relative. data/, installed packages and standalone directories keep strict physical containment, and a directory with installation artifacts (Meta/, R/<pkg>.rdb) is never treated as a source tree. Authors must still verify that built archives contain the data.

projectData 0.0.0.9005

Changes in this version

• One rule now selects the file behind a dataset. For data/ files, the built-in reader and the inventory both use the selection utils::data() makes: a name in the lazy-load map wins; otherwise the first supported extension in data()'s precedence order (R, r, RData, rdata, rda, then tables, then csv) for which <dataset>.<extension> exists. Previously inventory recorded whichever matching file was listed last, so with both dual.R and dual.rda the catalog could name the .rda while the script was opened, and removing the unused .rda could block retrieval. Now catalog source and the first-access message name the file actually read, lazy-load datasets still share data/Rdata.rdb, and removing an unused alternative has no effect. If the selected file is removed, opening fails with an error naming it and never falls back to another file; if a file with higher precedence has appeared since registration, opening is refused with a request to re-register (replace = TRUE) instead of silently reading something other than the recorded source (a dataset registered with no located file records no source, so a file restored later is simply read). Selection uses the directory listing and the small lazy-load map only. Files whose extension data() does not understand (for example x.rda.gz) are now reported as unsupported instead of being inventoried.
• Cleanup of the temporary view used to author against a package source tree is portable and checked. Links are removed as links and the verified-empty staging directory with unlink() instead of file.remove(); only entries created by the current operation are removed, and a link that was replaced by something else, or a directory that gained foreign files, is left in place. Link targets are never followed or deleted. Every removal is checked, and a failure is reported with a projectData_cleanup_warning naming what remains, without replacing the authoring error that triggered the cleanup. Cleanup is safe after partial staging, after success, and when repeated. Nothing is ever copied. This was developed and tested on Linux; it has not been run on Windows.
• The search-path environment that data_attach() creates is now removed by identity (its current position) in data_detach() and when the package is unloaded, and is captured by identity when it is attached. An unrelated search-path entry with the same name is left alone.
• Adapter work directories skip names that already exist, so reloading the package inside one R session no longer collides with directories made before.
• Package metadata: authors, maintainer and copyright holder are filled in from information in the repository (see DESCRIPTION); README, DESCRIPTION and LICENSE agree on the MIT license. The optional monocle3/BPCells check moved to dev/integration/, outside the package tests and the source tarball. Minimum versions of the test packages are declared (testthat 3.2.0 for local_mocked_bindings(), withr, tools), and tests remove the libraries and scratch files they create.

Behavior of this version

Attaching and retrieving

• data_attach() registers installed data packages (metadata only) and attaches them in one step as deferred active bindings in an environment named projectData:data. Nothing is attached when projectData loads. Objects are read on first use, after a message (data_config(messages = )).
• data_get(name, package = ) registers the package automatically if needed and returns the object without attaching anything; explicit and attached access share one resource cache. data_query() looks at packages without remembering them, data_detach() removes attached collections and forgets every registration, attached or not. It never deletes files.
• Name conflicts are never resolved by attachment order. Use a primary collection (data_primary()), per-object preferences (data_prefer()), suffix aliases or qualified data_get(name, collection = ). Resolution uses names only.
• Installed packages are resolved once, with their installation identity; if the installation changes before an object is opened, opening fails and asks for replace = TRUE.

Opening, caching, failure

• A resource is the loadable unit and can produce several objects; aliases and siblings share one canonical opening. Opening is guarded against reentrancy; a failed resource stays failed until data_retry(). on_open runs inside that guard.
• Object names recorded at registration are unchecked until a resource is opened. data_get() is strict about a missing object; data_inspect() replaces the recorded mapping with the observed names (rejecting duplicates within a collection, atomically).
• Script datasets (data/*.R) run only on first access, in a fresh output environment whose enclosing lookup chain is the fixed set of standard startup packages (stats, graphics, grDevices, utils, datasets, methods, base) and excludes the global workspace and attached packages. The chain is built only for script datasets. utils is detached again after utils::data() when it was not attached beforehand. See ?data_attach.

Catalog and provenance

• data_catalog() is metadata only: it never opens a resource or inspects values. Columns include origin (index, adapter, manifest), mapping (recorded, unknown, verified, mismatch), loader_status, storage and state. storage of a ready resource is the snapshot taken when it was opened, so later loader changes do not relabel it.

Loaders and adapters

• data_loader() defines contract version 1 (discover, validate, open); data_loader_add() and data_loader_adapter() register loaders atomically, and nothing is installed automatically. validate receives the same context as open and runs before every uncached opening. projectData::rds and projectData::dataset are built in.
• Adapter claims on standard datasets are ignored with a warning (data_config(ignored_claims = )); a manifest entry assigns such a resource to a specialized reader. Ambiguous adapter claims are errors.
• Disk-backed objects: detaching never deletes backing files; an object that references installed files can still break if the installation is replaced or removed. Adapters state whether they return installed-file references or a working copy (needs_work_dir).

Manifests

• An optional versioned DCF file, inst/projectData/manifest.dcf, declares loaders and mappings as data (never code). Reading, data_manifest_validate() and data_manifest_write() apply the same rules: one declaration per resource, unique object names across resources, strictly parsed Options.
• data_manifest_draft() and data_manifest_write() author manifests from the registered adapters' discovery. root can be a package source tree (needs symbolic links, see above), an installed package, or a standalone directory; Source paths are always installed-relative. Existing manifests are never overwritten without overwrite = TRUE, and nothing is written inside an installed package.

Not included

• A monocle3/BPCells adapter is deferred; the tiny disk-backed backend in inst/examples/tinydisk.R is the tested adapter example.
• ExperimentHub or other remote retrieval is a possible extension, not implemented.