selectMember: Return identifiers for objects that match search criteria

In datapack: A Flexible Container to Transport and Manipulate Data and Associated Resources

Return identifiers for objects that match search criteria

Description

Return DataObjects or DataObject identifiers that match search terms.

Usage

selectMember(x, ...)

## S4 method for signature 'DataPackage'
selectMember(x, name, value, as = "character")

Arguments

x	A DataPackage instance
...	(Not yet used)
name	The name of the DataObject slot to inspect, for example "sysmeta@formatId".
value	A character or logical value to match. If specified as a character value, PERL style regular expressions can be used (see ?grepl).
as	A character value to specify the return type, either "DataObject" or "character" (the default)

Details

The "selectMember" method inspects the DataObject slot "name" for a match with "value" for each DataObject in a DataPackage. Matching DataObjects are returned as a list containing either package member identifiers (character) or the DataObjects themselves, depending on the value of the as parameter.

Value

A list of matching DataObjects or DataObject identifiers. The default is to return a list of DataObject identifiers.

See Also

DataPackage-class

Examples

#' library(datapack)
dp <- new("DataPackage")
# Add the script to the DataPackage
progFile <- system.file("./extdata/pkg-example/logit-regression-example.R", package="datapack")
# An 'id' parameter is not specified, so one will be generated automatically.
progObj <- new("DataObject", format="application/R", filename=progFile)
dp <- addMember(dp, progObj)

# Add a script input to the DataPackage
inFile <- system.file("./extdata/pkg-example/binary.csv", package="datapack") 
inObj <- new("DataObject", format="text/csv", filename=inFile)
dp <- addMember(dp, inObj)

# Add a script output to the DataPackage
outFile <- system.file("./extdata/pkg-example/gre-predicted.png", package="datapack")
outObj <- new("DataObject", format="image/png", file=outFile)
dp <- addMember(dp, outObj)

# Now determine the package member identifier for the R script
progIds  <- selectMember(dp, name="sysmeta@formatId", value="application/R", as="character")
inputId <- selectMember(dp, name="sysmeta@fileName", value="binary.csv")

datapack documentation built on June 11, 2022, 1:05 a.m.