URL-encoding VARCHAR and TEXT values in PostgreSQL

Question

Are there any well-known PL functions/libraries for extending a PostgreSQL (9.4.1) database with URL encoding (also known as percent encoding) capabilities?

Here's an example of the intended functionality:

• Input string: International donor day: give blood for a good cause!
• Output string: International%20donor%20day%3A%20give%20blood%20for%20a%20good%20cause%21

I guess an alternative would be to roll out my own implementation, since AFAIK there is currently no built-in way of doing this.

Answer 1

This is trivial to do in an external PL,e.g.

CREATE LANGUAGE plpythonu;

CREATE OR REPLACE FUNCTION urlescape(original text) RETURNS text LANGUAGE plpythonu AS $$
import urllib
return urllib.quote(original);
$$
IMMUTABLE STRICT;