Create a persistent chain by linking new_daf to a base_daf.

Writes a base_daf_repository scalar on new_daf that points at base_daf's filesystem path. If axes and/or data are specified, the chain reads through a viewer() of base_daf and the spec is stored as JSON under base_daf_view. The returned chain is chain_writer(list( viewer_or_base, new_daf)).

Usage

complete_chain(
  base_daf,
  new_daf,
  name = NULL,
  axes = NULL,
  data = NULL,
  absolute = FALSE
)

Arguments

base_daf

A DafReader on disk (its path is stored).

new_daf

A DafWriter on disk (receives the pointer scalar).

name

Optional name for the returned chain.

axes, data

Optional viewer() axes / data spec applied on top of base_daf.

absolute

If TRUE, store the absolute base path (default is relative).

Value

The write chain.

Details

Call complete_daf() later to reopen the chain from disk using the stored scalars.

Examples

base_dir <- tempfile(); dir.create(base_dir)
new_dir <- tempfile(); dir.create(new_dir)
base <- files_daf(base_dir, name = "base", mode = "w+")
new <- files_daf(new_dir, name = "new", mode = "w+")
ch <- complete_chain(base_daf = base, new_daf = new, absolute = TRUE)