add a function to load additional workspaces

[davraam]

Is it a useful to have a "datashield.workspace_restore" function to allow users to restore more than one workspaces (in addition to the restore of a single workspace through the datashield.login(.... restore='xxx') function) and therefore to allow them to combine objects from the different workspaces?

[ymarcon]

Can be easily done, requires the following changes:

• DSI : addition of dsRestoreWorkspace (generic API) and datashield.workspace_restore (user API)
• DSOpal / DSLite / etc. : implementation of dsRestoreWorkspace
• Opal : addition of the REST entry point PUT /datashield/session/{id}/workspace/{ws}

Note that the side effect of this operation will be that any previously existing symbol will be overridden by the restored ones having the same name.

[ymarcon]

As a prototype, you can try this feature with DSLite

#install.packages("dsBase", repos = c("https://cloud.r-project.org", "https://cran.datashield.org"))

remotes::install_github("datashield/DSI", ref = "workspaces")
remotes::install_github("datashield/DSLite", ref = "workspaces")

library(DSLite)
library(dsBaseClient)

# prepare DSLite server
data("CNSIM1")
data("CNSIM2")
dslite.server <- newDSLiteServer(tables=list(CNSIM1=CNSIM1, CNSIM2=CNSIM2))

builder <- newDSLoginBuilder()
builder$append(server = "study1",  url = "dslite.server",
               table = "CNSIM1", driver = "DSLiteDriver")
logindata <- builder$build()
conns <- datashield.login(logins = logindata, assign = TRUE)
# save what was assigned at login
datashield.symbols(conns)
datashield.workspace_save(conns, "c1")
# assign a new table
datashield.assign.table(conns, "D2", list(study1 = "CNSIM2"))
datashield.symbols(conns)
# remove first data.frame and save workspace
datashield.rm(conns, "D")
datashield.symbols(conns)
datashield.workspace_save(conns, "c2")
# list saved workspaces
datashield.workspaces(conns)
datashield.logout(conns)

conns <- datashield.login(logins = logindata)
# verify no assignments
datashield.symbols(conns)
# verify available workspaces
datashield.workspaces(conns)
# restore c1
datashield.workspace_restore(conns, "c1")
datashield.symbols(conns)
# restore c2
datashield.workspace_restore(conns, "c2")
datashield.symbols(conns)
# verify data.frames are the ones expected
ds.summary("D")
ds.summary("D2")
# note that lsDS() is broken because it searches symbols in the .GlobalEnv instead of the parent.frame()
ds.ls()
datashield.logout(conns)