Download content from the connector — download

Generic implementing of how to download files from a connector:

ConnectorFS: Uses fs::file_copy() to copy a file from the file storage to the desired file.

ConnectorLogger: Logs the download operation and calls the underlying connector method.

Usage

download_cnt(connector_object, name, file = basename(name), ...)

# S3 method for class 'ConnectorFS'
download_cnt(connector_object, name, file = basename(name), ...)

# S3 method for class 'ConnectorLogger'
download_cnt(connector_object, name, file = basename(name), ...)

Arguments

connector_object: Connector The connector object to use.
name: character Name of the content to read, write, or remove. Typically the table name.
file: character Path to the file to download to or upload from
...: Additional arguments passed to the method for the individual connector.

Value

invisible connector_object.

Examples

# Download file from a file storage

folder <- withr::local_tempdir()
cnt <- connector_fs(folder)

cnt |>
  write_cnt("this is an example", "example.txt")
#> Error: Cannot open file for writing:
#> * '/tmp/RtmpnpFke0/file2106294e5648/example.txt'

list.files(pattern = "example.txt")
#> character(0)

cnt |>
  download_cnt("example.txt")
#> Error: [ENOENT] Failed to copy '/tmp/RtmpnpFke0/file2106294e5648/example.txt' to 'example.txt': no such file or directory

list.files(pattern = "example.txt")
#> character(0)
readLines("example.txt")
#> Warning: cannot open file 'example.txt': No such file or directory
#> Error in file(con, "r"): cannot open the connection

cnt |>
  remove_cnt("example.txt")
#> Error: [ENOENT] Failed to remove '/tmp/RtmpnpFke0/file2106294e5648/example.txt': no such file or directory

# Add logging to a file system connector for downloads
folder <- withr::local_tempdir()
cnt <- connectors(data = connector_fs(folder)) |> add_logs()

cnt$data |>
  write_cnt(iris, "iris.csv")
#> Error: Cannot open file for writing:
#> * '/tmp/RtmpnpFke0/file2106556fbd37/iris.csv'

cnt$data |>
  download_cnt("iris.csv", tempfile(fileext = ".csv"))
#> Error: [ENOENT] Failed to copy '/tmp/RtmpnpFke0/file2106556fbd37/iris.csv' to '/tmp/RtmpnpFke0/file21063ff76d27.csv': no such file or directory