Enhance elgg_echo to use vsprintf with argument swapping

[milan]

After looking at the new coding conventions I saw that inline variable interpolation was preferred over breaking up a string with variables. But I was thinking as elgg supoorts multiple languages then elgg_echo could easily be enhanced to use vsprintf so that variables could be imbedded to a string using it's format and argument swapping.

So if you were to use this elgg_echo function:

function elgg_echo($message_key, $language = "", $printf_args = array()) {
	
	global $CONFIG;
		
	static $CURRENT_LANGUAGE;
	if ((!$CURRENT_LANGUAGE) && (!$language)) 
		$CURRENT_LANGUAGE = $language = get_language();
	else 
		$language = $CURRENT_LANGUAGE;

	if (isset($CONFIG->translations[$language][$message_key])) {
		$message_key = $CONFIG->translations[$language][$message_key];
	} else if (isset($CONFIG->translations["en"][$message_key])) {
		$message_key = $CONFIG->translations["en"][$message_key];
	}
	
	// arguments in the sprintf string should use argument swapping
	if ($printf_args && is_array($printf_args)) {
		$message_key = vsprintf($message_key, $printf_args);
	}
		
	return $message_key;
	
}

so you could run some code like this:

// stored in the language file...
// elgg:language:monkey = 'The %2$s contains %1$d monkeys. That\'s a nice %2$s full of %1$d monkeys.'

echo elgg_echo('elgg:language:monkey', 'en', array('10', 'cage'));

which would allow language translations where the words in the sentence could be arranged in a different order.

[brettp]

(In [svn:7226]) Refs #1320: elgg_echo() has built-in sprintf support.

[brettp]

(In [svn:7227]) Refs #1320. Updated core to use elgg_echo()'s native string replacement.

[brettp]

(In [svn:7229]) Fixes #1320: Bundled mods use elgg_echo()'s internal string substitution.

[brettp]

If anyone is interested, I used the regex:

sprintf\((elgg_echo\([^\)]*)\),(\s+)?(.*)\)([,;\n])

to find the instances and

$1,$2array($3))$4

to replace them. This doesn't work for any embedded function calls or if the entire call is an argument to a function, so be careful.