Alternative function to PostgreSQL builtin initcap(text) with support for accented words.

initcap2_pg.sql

-- ========================================================================
-- Function:    initcap2(text)
-- Return Type: text
-- Description: Alternative function to builtin initcap(text). This function 
--              convert the first letter of each word to upper case and 
--              the rest to lower case EVEN IF the sentence has accented words.
-- Example:     initcap2('welcome to CHAMPS-ÉLYSÉES')
-- Result:      'Welcome To Champs-Élysées'
--
-- License: MIT
-- Copyright (c) 2013 Pablo O Vieira (povieira)
-- 
-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
-- 
-- The above copyright notice and this permission notice shall be included in
-- all copies or substantial portions of the Software.
-- 
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-- THE SOFTWARE.
-- ========================================================================
CREATE OR REPLACE FUNCTION initcap2(text)
  RETURNS text
  LANGUAGE plpgsql
AS
$body$
DECLARE 
	sentence TEXT := '';
	word_array TEXT[];
	word TEXT;
	word_out TEXT;
BEGIN
	sentence := $1;

	IF sentence is NULL THEN
		RETURN NULL;
	END IF;
	
	word_array := regexp_split_to_array($1, E'[\\[\\]\^\$\.\|\?\*\+\(\)\\~`\!@#%&\\-\\_+={}''"<>:;, ]');
	FOREACH word IN ARRAY word_array
	LOOP
		word_out := translate(upper(left(word, 1)), text 'áéíóúàèìòùãõâêîôôäëïöüç', text 'ÁÉÍÓÚÀÈÌÒÙÃÕÂÊÎÔÛÄËÏÖÜÇ') 
			|| translate(lower(substring(word, 2)), text 'ÁÉÍÓÚÀÈÌÒÙÃÕÂÊÎÔÛÄËÏÖÜÇ', text 'áéíóúàèìòùãõâêîôôäëïöüç');
		sentence := regexp_replace(sentence, word, word_out);
	END LOOP;
	
	RETURN trim(sentence);
END;
$body$
 IMMUTABLE
 COST 100
/

Actually, I realized that initcap2 was a waste of time since I could just use the PostgreSQL Collation Support (since version 9.x) when database is not using UTF-8:

select initcap('welcome to CHAMPS-ÉLYSÉES' collate "fr_FR")

will result:

initcap
-------------------------
Welcome To Champs-Élysées'