PHP: building a URL path - php

Question

I have a few strings to combine to build a full path. e.g.
$base = "http://foo.com";
$subfolder = "product/data";
$filename = "foo.xml";
// How to do this?
$url = append_url_parts($base, $subfolder, $filename); ???
String concatenation won't do, that would omit the necessary forward slashes.
In Win32 I'd use PathCombine() or PathAppend(), which would handle adding any necessary slashes between strings, without doubling them up. In PHP, what should I use?

Answer 1

Try this:
$base = "http://foo.com";
$subfolder = "product/data";
$filename = "foo.xml";
function stripTrailingSlash(&$component) {
$component = rtrim($component, '/');
}
$array = array($base, $subfolder, $filename);
array_walk_recursive($array, 'stripTrailingSlash');
$url = implode('/', $array);

Answer 2

when it comes down to something like this I like to use a special function with unlimited parameters.
define('BASE_URL','http://mysite.com'); //Without last slash
function build_url()
{
return BASE_URL . '/' . implode(func_get_args(),'/');
}
OR
function build_url()
{
$Path = BASE_URL;
foreach(func_get_args() as $path_part)
{
$Path .= '/' . $path_part;
}
return $Path;
}
So that when I use the function I can do
echo build_url('home'); //http://mysite.com/home
echo build_url('public','css','style.css'); //http://mysite.com/public/css/style.css
echo build_url('index.php'); //http://mysite.com/index.php
hope this helps you, works really well for me especially within an Framework Environment.
to use with params you can append the url like so for simplicity.
echo build_url('home') . '?' . http_build_query(array('hello' => 'world'));
Would produce: http://mysite.com/home?hello=world

Answer 3

not sure why you say string concat won't do, because something like this is basically similar to a string concat. (untested semi-pseudo)
function append_url_parts($base, $subf, $file) {
$url = sprintf("%s%s%s", $base, (($subf)? "/$subf": ""), (($file)? "/$file": ""));
return $url;
}
with string concat, we'd have to write a slightly longer block like so:
function append_url_parts($base, $subf, $file) {
$subf = ($subf)? "/$subf": "";
$file = ($file)? "/$file": "";
$url = "$base$subf$file";
return $url;
}

Answer 4

I usually go simple:
<?
$url = implode('/', array($base, $subfolder, $filename));
Either that or use a framework, and then use whatever route system it has.

Answer 5

There are a few considerations first.
Are you interested in getting the current path of the script or some other path?
How flexible do you need this to be? Is it something that is going to change all the time? Is it something an admin will set once and forget?
You want to be careful not to include the slash bug where your document has a slash added at the end because you were too lazy to figure out how to separate directory vars from the file var. There will only be one file and one base per URL and unknown number of directories in each path, right? :)

Answer 6

If you want to make sure there are no duplicate slashes within the resultant path, I like this little function...simply pass it an array of path part you want combined and it will return a formatted path - no need to worry whether any of the parts contain a slash alerady or not:
function build_url($arr)
{
foreach ( $arr as $path ) $url[] = rtrim ( $path, '/' );
return implode( $url, '/' );
}
This should work on all versions of PHP too.

Answer 7

Not my code, but a handy function which takes an absolute URL and a relative URL and combines the two to make a new absolute path.
The function has been modified to ignore an absolute URL passed as relative ( basically anything that includes a schema ).
$url = "http://www.goat.com/money/dave.html";
$rel = "../images/cheese.jpg";
$com = InternetCombineURL($url,$rel);
public function InternetCombineUrl($absolute, $relative) {
$p = parse_url($relative);
if(isset($p["scheme"]))return $relative;
extract(parse_url($absolute));
$path = dirname($path);
if($relative{0} == '/') {
$cparts = array_filter(explode("/", $relative));
}
else {
$aparts = array_filter(explode("/", $path));
$rparts = array_filter(explode("/", $relative));
$cparts = array_merge($aparts, $rparts);
foreach($cparts as $i => $part) {
if($part == '.') {
$cparts[$i] = null;
}
if($part == '..') {
$cparts[$i - 1] = null;
$cparts[$i] = null;
}
}
$cparts = array_filter($cparts);
}
$path = implode("/", $cparts);
$url = "";
if($scheme) {
$url = "$scheme://";
}
if(isset($user)) {
$url .= "$user";
if($pass) {
$url .= ":$pass";
}
$url .= "#";
}
if($host) {
$url .= "$host/";
}
$url .= $path;
return $url;
}

Answer 8

I wrote this function for all cases to combine url parts with no duplicate slashes.
It accepts many arguments or an array of parts.
Some parts may be empty strings, that does not produce double slashes.
It keeps starting and ending slashes if they are present.
function implodePath($parts)
{
if (!is_array($parts)) {
$parts = func_get_args();
if (count($parts) < 2) {
throw new \RuntimeException('implodePath() should take array as a single argument or more than one argument');
}
} elseif (count($parts) == 0) {
return '';
} elseif (count($parts) == 1) {
return $parts[0];
}
$resParts = [];
$first = array_shift($parts);
if ($first === '/') {
$resParts[] = ''; // It will keep one starting slash
} else {
// It may be empty or have some letters
$first = rtrim($first, '/');
if ($first !== '') {
$resParts[] = $first;
}
}
$last = array_pop($parts);
foreach ($parts as $part) {
$part = trim($part, '/');
if ($part !== '') {
$resParts[] = $part;
}
}
if ($last === '/') {
$resParts[] = ''; // To keep trailing slash
} else {
$last = ltrim($last, '/');
if ($last !== '') {
$resParts[] = $last; // Adding last part if not empty
}
}
return implode('/', $resParts);
}
Here is a check list from unit test. Left array is input and right part is result string.
[['/www/', '/eee/'], '/www/eee/'],
[['/www', 'eee/'], '/www/eee/'],
[['www', 'eee'], 'www/eee'],
[['www', ''], 'www'],
[['www', '/'], 'www/'],
[['/www/', '/aaa/', '/eee/'], '/www/aaa/eee/'],
[['/www', 'aaa/', '/eee/'], '/www/aaa/eee/'],
[['/www/', '/aaa/', 'eee/'], '/www/aaa/eee/'],
[['/www', 'aaa', 'eee/'], '/www/aaa/eee/'],
[['/www/', '/aaa/'], '/www/aaa/'],
[['/www', 'aaa/'], '/www/aaa/'],
[['/www/', 'aaa/'], '/www/aaa/'],
[['/www', '/aaa/'], '/www/aaa/'],
[['/www', '', 'eee/'], '/www/eee/'],
[['www/', '/aaa/', '/eee'], 'www/aaa/eee'],
[['/www/', '/aaa', ''], '/www/aaa'],
[['', 'aaa/', '/eee/'], 'aaa/eee/'],
[['', '', ''], ''],
[['aaa', '', '/'], 'aaa/'],
[['aaa', '/', '/'], 'aaa/'],
[['/', 'www', '/'], '/www/'],
It can be used as implodePath('aaa', 'bbb') or implodePath(['aaa', 'bbb'])