Custom data storage formats

targets 0.10.0

Bug fixes

• Add class "tar_nonexportable" to format = "aws_keras" and format = "aws_torch" stores.
• Export S3 methods of generic tar_make_interactive_load_target().

New features

• Allow entirely custom storage formats through tar_target(format = tar_format(...)) (#736).
• Add a new function tar_call() to return the targets function currently running (from _targets.R or a target).
• Add a new function tar_active() to tell whether the pipeline is currently running. Detects if it is called from tar_make() or similar function.

Enhancements

• Add Sys.getenv("TAR_PROJECT") to the output of tar_envvars().
• Set the store field of tar_runtime prior to sourcing _targets.R so tar_store() works in target scripts.
• Explicitly export all the environment variables from tar_envvars() to targets run on parallel workers.
• Allow format = "file" targets to return character(0) (#728, @programLyrique).
• Automatically remove non-targets from the target list and improve target list error messages (#731, @billdenney).
• Link to resources on deploying to RStudio Connect (#745, @ian-flores).