Help with url rewrite

Question

How can I turn a URL like:

http://site.com/?project=5

into:

http://site.com/project/5/

?

I was looking the rewrite doc here: http://codex.wordpress.org/Class_Reference/WP_Rewrite#Examples

and came up with this

// Adding a new rule
function my_insert_rewrite_rules( $rules )
{
  $newrules = array();
  $newrules['(project)/(\d*)$'] = 'index.php?project=$matches[2]';
  return $newrules + $rules;
}

// Adding the id var so that WP recognizes it
function my_insert_query_vars( $vars )
{
    array_push($vars, 'project');
    return $vars;
}

add_filter( 'rewrite_rules_array','my_insert_rewrite_rules' );
add_filter( 'query_vars','my_insert_query_vars' );
add_action( 'wp', 'test');

function test()
{
 global $wp_rewrite;
 $wp_rewrite->flush_rules();
 if(isset($_GET['project'])){
   echo $_GET['project'];
   exit;
 }

};

but it doesn't work when I access for example http://site.com/project/2/

Answer 1

The PHP code is not enough, you need to edit your .htaccess file correspondingly. (You can do this with $wp_rewrite->mod_rewrite_rules(); somehow, or edit it manually.) However, be aware that URL rewriting is complicated stuff - are you sure you need it? If you are using pretty permalinks for posts/pages, chances are this will bork it up.

Answer 2

The simple way to do this is to create a page, and give it the slug project.

Then add your rewrite rule and query var:

add_action( 'init', 'my_insert_rewrite_rules' );
function my_insert_rewrite_rules(){
    add_rewrite_rule(
        'project/([0-9]+)/?$',
        'index.php?pagename=project&project=$matches[1]',
        'top' );
}

add_filter( 'query_vars', 'my_insert_query_vars' );
function my_insert_query_vars( $query_vars ){
    $query_vars[] = 'project';
    return $query_vars;
}

Then in your template, use get_query_var('project'); to retrieve the value of project.