connector (version 1.0.0)

read_cnt: Read content from the connector

Description

Generic implementing of how to read content from the different connector objects:

• ConnectorDBI: Uses DBI::dbReadTable() to read the table from the DBI connection.

• ConnectorFS: Uses read_file() to read a given file. The underlying function used, and thereby also the arguments available through ... depends on the file extension.

The file is located using internal function, which searches for files matching the provided name. If multiple files match and no extension is specified, it will use the default extension (configurable via options(connector.default_ext = "csv"), defaults to "csv").

• ConnectorLogger: Logs the read operation and calls the underlying connector method.

Usage

read_cnt(connector_object, name, ...)
# S3 method for ConnectorDBI
read_cnt(connector_object, name, ...)
# S3 method for ConnectorFS
read_cnt(connector_object, name, ...)
# S3 method for ConnectorLogger
read_cnt(connector_object, name, ...)

Value

R object with the content. For rectangular data a data.frame.

Arguments

connector_object

Connector The connector object to use.

name

character Name of the content to read, write, or remove. Typically the table name.

...

Additional arguments passed to the method for the individual connector.

Examples

# Read table from DBI database
cnt <- connector_dbi(RSQLite::SQLite())

cnt |>
  write_cnt(iris, "iris")

cnt |>
  list_content_cnt()

cnt |>
  read_cnt("iris") |>
  head()

# Write and read a CSV file using the file storage connector

folder <- withr::local_tempdir("test", .local_envir = .GlobalEnv)

cnt <- connector_fs(folder)

cnt |>
  write_cnt(iris, "iris.csv")

cnt |>
  read_cnt("iris.csv") |>
  head()

# Add logging to a file system connector
folder <- withr::local_tempdir("test", .local_envir = .GlobalEnv)

cnt <- connectors(data = connector_fs(folder)) |> add_logs()

cnt$data |>
  write_cnt(iris, "iris.csv")

cnt$data |>
  read_cnt("iris.csv", show_col_types = FALSE) |>
  head()