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A generator for making request to OpenAlex API Returns one record at a time.

Usage

oa_generate(...)

Arguments

...

arguments passed to the generator including `query_url`, `mailto`, `api_key`, and `verbose`. See `oa_request` for details on these arguments.

Value

Generator function.

Details

For the case without group_by, setting `verbose = TRUE` when you call `oar()` for the first time will give the total number of records in the message. With group_by, unfortunately we don't have a way to know the total until we query until exhausted.

Examples

if (require("coro")) {
  # Example 1: basic usage getting one record at a time
  query_url <- "https://api.openalex.org/works?filter=cites%3AW1160808132"
  oar <- oa_generate(query_url, verbose = TRUE)
  p1 <- oar() # record 1
  p2 <- oar() # record 2
  p3 <- oar() # record 3
  head(p1)
  head(p3)

  # Example 2: using `coro::loop()` to iterate through the generator
  query_url <- "https://api.openalex.org/works?filter=cited_by%3AW1847168837"
  oar <- oa_generate(query_url)
  coro::loop(for (x in oar) {
    print(x$id)
  })

  # Example 3: save records in blocks of 100
  query_url <- "https://api.openalex.org/works?filter=cites%3AW1160808132"
  oar <- oa_generate(query_url)
  n <- 100
  recs <- vector("list", n)
  i <- 0

  coro::loop(for (x in oar) {
    j <- i %% n + 1
    recs[[j]] <- x
    if (j == n) {
      # saveRDS(recs, sprintf("rec-%s.rds", i %/% n))
      recs <- vector("list", n) # reset recs
    }
    i <- i + 1
  })
  head(x)
  j
  # 398 works total, so j = 98 makes sense.

  # You can also manually call the generator until exhausted
  # using `while (!coro::is_exhausted(record_i))`.
  # More details at https://coro.r-lib.org/articles/generator.html.

}
#> Loading required package: coro
#> Getting record 1 of 479 records...
#> Getting record 2 of 479 records...
#> Getting record 3 of 479 records...
#> [1] "https://openalex.org/W4248184440"
#> [1] "https://openalex.org/W1521059904"
#> [1] "https://openalex.org/W2063977404"
#> [1] "https://openalex.org/W1987736762"
#> [1] "https://openalex.org/W2127626512"
#> [1] "https://openalex.org/W2135732400"
#> [1] 79