.htaccess : remove index.php in the url if there is no querystring - .htaccess

Question

I want to remove index.php in the url if there is no querystring.
My .htaccess is:
RewriteCond %{QUERY_STRING} ^$
RewriteRule index.php http://www.domain.fr [R=301,L]
RewriteRule ^(.*)/(.*)/$ index.php?category=$1&region=$2 [L,QSA]
www.domain.fr/index.php => ok, redirects well to www.domain.fr
www.domain.fr/index.php?i=1 => ok, no redirection
www.domain.fr/category/region/ (if entered manually in the url) => ok, no redirection
www.domain.fr/category/region/ (if posted via a php form) => redirect (and shouldn't) to www.domain.fr
Here is my php form:
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
<select id="category" name="category">..</select>
<input id="send" name="send" type="submit" value="search" />
</form>
and the code of this form (at the top of the page):
if(isset($_POST['send'])){
$category = $_POST['category'];
$region = $_POST['region'];
header('Location: http://www.domain.fr/$category/$region/');
exit;
}
If I remove the cond RewriteCond %{QUERY_STRING} ^$ the php form redirects well to www.domain.fr/category/region, but if I put the cond it redirects always to www.domain.fr,
any idea ?

Answer 1

Your order of rules is the problem, keep your rules like this:
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^domain\.fr$ [NC]
RewriteRule ^ http://www.%{HTTP_HOST}%{REQUEST_URI} [R=302,NE,L]
RewriteCond %{THE_REQUEST} /index\.php[^?] [NC]
RewriteCond %{QUERY_STRING} ^$
RewriteRule ^index\.php$ / [R=302,L]
RewriteRule [A-Z] ${lc:%{REQUEST_URI}} [R=302,L]
RewriteRule .* - [E=SD:${vhost:%{HTTP_HOST}}]
RewriteCond %{REQUEST_FILENAME} -d [OR]
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^ - [L]
RewriteRule ^([^/]+)/([^/]+)/?$ index.php?category=$1&region=$2 [L,QSA]
RewriteRule ^([^/]+)/?$ index.php?category=$1 [L,QSA]

Answer 2

Anubhava I've found the answer!!!
the problem was just about the php form, it's needed to remove:
<?php echo $_SERVER['PHP_SELF'];?>
The solution is simply:
<form method="post" action="">
but than kyou very much Anubhava!