Clean way to write urls instead of concatenation - php

Question

I have been finding myself doing URLs like this:
$link = base_url('post') . '/' . $post_id . '/' . $slug . '/page/' . $page_num;
To form http://example.com/post/10/some-post-name/page/1
Needless to say, it's pretty messy, but I can't think of an alternative? Is there a better way write links with variables in it?
I am using Codeigniter as a framework if there is a solution involving it.

Answer 1

You have a few ways:
First, via sprintf:
sprintf('%s/%s/%s/page/%s', base_url('post'), $post_id, $slug, $page_num);
Or via an array implode:
implode('/', array(base_url('post'), $post_id, $slug, 'page', $page_num));
Or if you put all your values into variables, you can take advantage of string interpolation.
$url = ...;
...
"$url/$post_id/$slug/page/$page_num";
The last one is longer when you take into account the variable assignment block, but it combines succintness with readability.

Answer 2

Use sprintf:
$link = sprintf('%s/%d/%s/page/%d', base_url('post'), $post_id, $slug, $page_num);

Answer 3

You could do something like this:
$link = site_url("post/{$post_id}/{$slug}/page/{$page_num}");
You really should be using site_url() instead of base_url() for CI links. base_url() is meant for non-CI assets, like images and css.
site_url() will point to the correct front controller path, so you can update your configuration at will, and everything using that to build paths will update accordingly.
I revised my answer. Use the curly brace notation and avoid using extra functions. You can pass an array of arguments to the function, like so:
$link = site_url(array('post', $post_id, $slug, 'page', $page_num));
But working with arrays is slower. This can be useful if you need to dynamically build the url, though.

Answer 4

You could do it the old fashioned way with a function!
function buildlink($base_url,$post_id,$slug,$page_num)
{
return $base_url . '/' . $post_id . '/' . $slug . '/page/' . $page_num;
}
call it like this
$link = buildlink(base_url('post') ,$post_id, $slug ,$page_num);
but maybe i'm missing something