alm.R

library(rAltmetric)
library(purrr)
# we launch purrr because it gives us the safely function


ids <- c("10.1371/journal.pbio.0000002",
         "10.1371/journal.pbio.0000003",
         "10.1371/journal.pbio.0000004",
         "10.1371/journal.pbio.0000005",
         "10.1371/journal.pbio.0000006",
         "10.1371/journal.pbio.0000007",
         "10.1371/journal.pbio.0000008",
         "10.1371/journal.pbio.0000009"
)


ids2 <- as.list(ids)

safe_metrics <- safely(altmetrics)

metric_data <- function(x) {
  alm <- safe_metrics(doi = x)
  # Safely ensures that the function returns NULL if nothing else comes out
  if(is.null(alm$result)) {
    NULL
  } else {
    data.frame(t(unlist(alm$result)), stringsAsFactors = FALSE)
  }
  }


results <- lapply(ids2, metric_data)
# This next bit removes NULL (ie. dois for which there were no metrics)
results <- Filter(Negate(is.null), results)
# Now this is a list of lists. You can flatten now as you please