ds.names.RdReturns the names of a designated server-side list
ds.names(xname = NULL, datasources = NULL)a character string specifying the name of the list.
a list of DSConnection-class
objects obtained after login that represent the particular data sources
(studies) to be addressed by the function call. If the datasources
argument is not specified the default set of connections will be used:
see datashield.connections_default.
ds.names returns to the client-side the names
of a list object stored on the server-side.
ds.names calls aggregate function namesDS. This function is similar to
the native R function names but it does not subsume all functionality,
for example, it only works to extract names that already exist,
not to create new names for objects. The function is restricted to objects of
type list, but this includes objects that have a primary class other than list but which
return TRUE to the native R function is.list. As an example this includes
the multi-component object created by fitting a generalized linear model
using ds.glmSLMA. The resultant object saved on each server separately
is formally of class "glm" and "ls" but responds TRUE to is.list(),
if (FALSE) { # \dontrun{
## Version 6, for version 5 see the Wiki
# connecting to the Opal servers
require('DSI')
require('DSOpal')
require('dsBaseClient')
builder <- DSI::newDSLoginBuilder()
builder$append(server = "study1",
url = "http://192.168.56.100:8080/",
user = "administrator", password = "datashield_test&",
table = "CNSIM.CNSIM1", driver = "OpalDriver")
builder$append(server = "study2",
url = "http://192.168.56.100:8080/",
user = "administrator", password = "datashield_test&",
table = "CNSIM.CNSIM2", driver = "OpalDriver")
builder$append(server = "study3",
url = "http://192.168.56.100:8080/",
user = "administrator", password = "datashield_test&",
table = "CNSIM.CNSIM3", driver = "OpalDriver")
logindata <- builder$build()
connections <- DSI::datashield.login(logins = logindata, assign = TRUE, symbol = "D")
#Create a list in the server-side
ds.asList(x.name = "D",
newobj = "D.list",
datasources = connections)
#Get the names of the list
ds.names(xname = "D.list",
datasources = connections)
# clear the Datashield R sessions and logout
datashield.logout(connections)
} # }