query_epigraphdb {epigraphdb}

Send data request to an EpiGraphDB API endpoint

Description

This is a general purpose function to send data request which can be used when there has not been an R equivalent package function to an API endpoint. Underneath this is a wrapper around httr functions with better handling of returned status.

Usage

query_epigraphdb(
  route,
  params = NULL,
  mode = c("raw", "table"),
  method = c("GET", "POST"),
  retry_times = 3,
  retry_pause_min = 1
)

Arguments

route

An EpiGraphDB API endpoint route, e.g. "/mr" or "/confounder". Consult the EpiGraphDB API documentation.

params

A list of parameters associated with the query endpoint.

mode

c("raw", "table"), if "table" then the query handler will try to convert the returned data to a tibble dataframe. NOTE: The default mode is "raw" which will NOT convert the returned response to a dataframe. This is different to functions that query topic endpoints which default to return a dataframe. Explicitly specify mode = "table" when needed.

method

Type of HTTP (GET, POST, PUT, etc.) method.

NOTE: When sending a POST request where a specific parameter is specified as a list on the API, and if the equivalent in R is a vector of length 1, you should wrap this parameter in I(), e.g. I(c("APOE")) to avoid auto unboxing. For details, please refer to httr::POST

retry_times

Number of times the function will retry the request to the API.

retry_pause_min

Minimum number of seconds to wait for the next retry.

Value

Data from an EpiGraphDB API endpoint.

Examples

# GET /mr
# equivalent to `mr(exposure_trait = "Body mass index", outcome_trait = "Coronary heart disease")`
## Not run: 
query_epigraphdb(
  route = "/mr",
  params = list(
    exposure_trait = "Body mass index",
    outcome_trait = "Coronary heart disease"
  ),
  mode = "table"
)

## End(Not run)

# GET /meta/nodes/Gwas/list
## Not run: 
query_epigraphdb(
  route = "/meta/nodes/Gwas/list",
  params = list(
    limit = 5,
    offset = 0
  )
) %>% str(1)

## End(Not run)

# POST /protein/ppi
## Not run: 
query_epigraphdb(
  route = "/protein/ppi",
  params = list(
    uniprot_id_list = c("P30793", "Q9NZM1", "O95236")
  ),
  method = "POST"
)

## End(Not run)

# error handling
## Not run: 
tryCatch(
  query_epigraphdb(
    route = "/mr",
    params = list(
      exposure_trait = NULL,
      outcome_trait = NULL
    ),
    retry_times = 0
  ),
  error = function(e) {
    message(e)
  }
)

## End(Not run)