Encode or decode a URI
encodes or decodes a URI/URL
url_decode(urls)
url_encode(urls)
Arguments
urls: a vector of URLs to decode or encode.
Returns
a character vector containing the encoded (or decoded) versions of "urls".
Details
URL encoding and decoding is an essential prerequisite to proper web interaction and data analysis around things like server-side logs. The relevant IETF RfC mandates the percentage-encoding of non-Latin characters, including things like slashes, unless those are reserved.
Base R provides URLdecode and URLencode, which handle URL encoding - in theory. In practise, they have a set of substantial problems that the urltools implementation solves::
- No vectorisation:Both base R functions operate on single URLs, not vectors of URLs. This means that, when confronted with a vector of URLs that need encoding or decoding, your only option is to loop from within R. This can be incredibly computationally costly with large datasets. url_encode and url_decode are implemented in C++ and entirely vectorised, allowing for a substantial performance improvement.
- No scheme recognition:encoding the slashes in, say, http://, is a good way of making sure your URL no longer works. Because of this, the only thing you can encode in URLencode (unless you refuse to encode reserved characters) is a partial URL, lacking the initial scheme, which requires additional operations to set up and increases the complexity of encoding or decoding. url_encode detects the protocol and silently splits it off, leaving it unencoded to ensure that the resulting URL is valid.
- ASCII NULs:Server side data can get very messy and sometimes include out-of-range characters. Unfortunately, URLdecode's response to these characters is to convert them to NULs, which R can't handle, at which point your URLdecode call breaks.
url_decode simply ignores them.
Examples
url_decode("https://en.wikipedia.org/wiki/File:Vice_City_Public_Radio_%28logo%29.jpg")
url_encode("https://en.wikipedia.org/wiki/File:Vice_City_Public_Radio_(logo).jpg")
## Not run:
#A demonstrator of the contrasting behaviours around out-of-range characters
URLdecode("%gIL")
url_decode("%gIL")
## End(Not run)
See Also
puny_decode and puny_encode, for punycode decoding and encoding.