An abstraction that holds information needed to make an epidata request

epidata_call objects are generated internally by endpoint functions like pub_covidcast; by default, they are piped directly into the fetch function to fetch and format the data. For most endpoints this will return a tibble, but a few non-COVIDCAST endpoints will return a JSON-like list instead.

Usage

create_epidata_call(
  endpoint,
  params,
  meta = NULL,
  api_version = c("classic", "cast"),
  response_format = c("classic", "json", "csv")
)

fetch(epidata_call, fetch_args = fetch_args_list())

Arguments

endpoint: the epidata endpoint to call
params: the parameters to pass to the epidata endpoint
meta: meta data to attach to the epidata call
api_version: string. The API version to use. One of "classic" or "cast".
response_format: string. The expected format of the response. One of "classic", "json", or "csv".
epidata_call: an instance of epidata_call
fetch_args: a fetch_args object

Value

For create_epidata_call: an epidata_call object

For fetch: a tibble

Details

create_epidata_call is the constructor for epidata_call objects, but you should not need to use it directly; instead, use an endpoint function, e.g., pub_covidcast, to generate an epidata_call for the data of interest.

Examples

# Build the request without sending it
call <- epidata_snapshot(
  source = "nssp",
  signals = "pct_ed_visits_influenza",
  geo_type = "state",
  geo_values = c("pa", "ca"),
  reference_time = epirange("2024-12-01", "2024-12-31"),
  fetch_args = fetch_args_list(dry_run = TRUE)
)
call
#> 
#> ── <epidata_call> object: ──────────────────────────────────────────────────────
#> • Pipe this object into `fetch()` to actually fetch the data
#> • Request URL:
#>   https://delphi.cmu.edu/epidata/v5/snapshot/?source=nssp&signal=pct_ed_visits_influenza&geo_type=state&geo_value=pa%2Cca&reference_times=2024-12-01%3A2024-12-31

# Send it and get the data
fetch(call)
#> # A tibble: 8 × 7
#>   signal report_time         geo_type geo_value fill_method reference_time value
#>   <chr>  <dttm>              <chr>    <chr>     <chr>       <date>         <dbl>
#> 1 pct_e… 2025-02-03 12:00:00 state    pa        source      2024-12-28     3.93 
#> 2 pct_e… 2025-01-17 12:00:00 state    pa        source      2024-12-07     0.570
#> 3 pct_e… 2025-01-24 12:00:00 state    pa        source      2024-12-21     1.81 
#> 4 pct_e… 2025-01-24 12:00:00 state    pa        source      2024-12-14     0.870
#> 5 pct_e… 2026-07-29 12:00:00 state    ca        source      2024-12-07     1.68 
#> 6 pct_e… 2026-08-05 12:00:00 state    ca        source      2024-12-14     2.55 
#> 7 pct_e… 2026-08-05 12:00:00 state    ca        source      2024-12-28     6.70 
#> 8 pct_e… 2026-08-05 12:00:00 state    ca        source      2024-12-21     4.48