Safely extract JSON

A wrapper around jsonlite::fromJSON that returns a list instead of throwing an error when JSON parsing fails. Uses purrr::possibly to provide graceful error handling. To be explicit: you will not receive an error message if your JSON failed to parse, just an empty list. This property allows you to handle NULL/NA results in the way you'd like to.

Usage

safely_from_json(...)

Arguments

...

Arguments passed to jsonlite::fromJSON. The first argument should be txt (a JSON string, URL or file to parse). Additional arguments include: simplifyVector (coerce JSON arrays containing only primitives to atomic vectors, default TRUE), simplifyDataFrame (coerce JSON arrays containing objects to data frames, default TRUE), simplifyMatrix (coerce JSON arrays containing equal-length sub-arrays to matrices, default TRUE), and flatten (automatically flatten nested data frames, default FALSE).

Value

Parsed JSON object on success, empty list on failure

See also

jsonlite::fromJSON(), purrr::possibly()

Examples

# Valid JSON
safely_from_json('{"name": "John", "age": 30}')
#> $name
#> [1] "John"
#> 
#> $age
#> [1] 30
#> 

# Invalid JSON returns empty list instead of error
safely_from_json('{"invalid": json}')
#> list()

# Works with URLs and files too
safely_from_json("https://api.example.com/data.json")
#> Warning: URL 'https://api.example.com/data.json': status was 'Couldn't resolve host name'
#> list()