array_map_recursive
Jul/090
Not much needs to be said here.
$ret = array();
foreach($arr as $key => $val) {
if(is_array($val)) $ret[$key] = array_map_recursive($callback, $val);
else $ret[$key] = $callback($val);
}
return $ret;
}
I wrote this so that I could do this…
foreach($filters as $filter) $view_vars = array_map_recursive($filter, $view_vars);
Which just sanitizes my variables before I print them.
SQL Injection Safe Queries Redux
Jun/092
if(is_numeric($value)) return $value;
elseif(empty($value)) return 'NULL';
elseif(is_string($value)) return '\''.mysql_real_escape_string($value).'\'';
elseif(is_array($value)) return implode(',',array_map('mysql_safe_string',$value));
}
function mysql_safe_query($format) {
$args = array_slice(func_get_args(),1);
$args = array_map('mysql_safe_string',$args);
$query = vsprintf($format,$args);
$result = mysql_query($query);
if($result === false) echo '<div class="mysql-error"><strong>Error: </strong>',mysql_error(),'<br/><strong>Query: </strong>',$query,'</div>';
return $result;
}
// example
$result = mysql_safe_query('SELECT * FROM users WHERE username=%s', $username);
Just use mysql_safe_query in place of mysql_query and you should be safe from SQL injection attacks. Use %s in place of any variables, and append them as arguments. Don’t quote your strings, it’ll be done for you automatically. Arrays will be flattened for you automatically and concatenated with commas. You can delete the error-echoing line if you want, but I find it useful for development.
Facebook PHP API: Get the names of all your friends
Jun/090
If you didn’t already know, Facebook has an API that exposes quite a darn bit information. You can easily query this data using their API, but each request takes a fair bit of time. Typically, to get the names of all your friends, first you have to grab a list of the user ids of all your friends, and then query each and every single one to get their names. For me, that’s about 300 cross-server requests, which will almost certainly cause my server to time out, and probably force Facebook to reject me. Fortunately, Facebook has also created their own MySQL-like language, FQL (I pronounce it feequel), which lets you do some of these “complicated” queries in a single call. Here’s a simple example I wrote:
require_once 'facebook-platform/php/facebook.php';
$appapikey = 'yourapikeyhere';
$appsecret = 'yoursecretkey';
$facebook = new Facebook($appapikey, $appsecret);
$user_id = $facebook->require_login();
$result = fql_query('SELECT name FROM user WHERE uid IN (SELECT uid2 FROM friend WHERE uid1=%s)', $user_id);
pr($result);
function fql_query($query) {
global $facebook;
$args = array_slice(func_get_args(), 1);
return $facebook->api_client->fql_query(vsprintf($query, $args));
}
function pr($arr) {
echo '<pre>';
print_r($arr);
echo '</pre>';
}
You’ll notice I’ve included two of my favorite wrapper functions. You can unroll them if you want. Anyway, just thought I’d share 
I prefer writing FQL than trying to remember all their API calls anyway.
Oh… and just FYI, this prints out something like this:
Array
(
[0] => Array
(
[name] => Mark Zuckerberg
)
[1] => Array
(
[name] => Tom Riddle
)
I hate it when people leave it a mystery what exactly their example is doing!
Get Domain & Subdomain from URL
Jun/092
define('PROTOCOL', strtolower(substr($_SERVER['SERVER_PROTOCOL'],0,strpos($_SERVER['SERVER_PROTOCOL'],'/'))).'://');
define('SUBDOMAIN', $matches[1]);
define('DOMAIN', $matches[2]);
define('HERE', $_SERVER['REQUEST_URI']);
If you’re at http://www.sub.domain.com/page, then:
PROTOCOL = http://
SUBDOMAIN = sub
DOMAIN = domain.com
HERE = /page
PHP code for handling recursive categories/hierarchical data
Jun/090
I’m just going to paste the code I wrote here… you can read some other tutorial to understand what it’s doing, but for some reason they have really incomplete examples, so here’s the whole shabang. It will even keep your nodes in alphabetical order. It has a function for displaying a drop down list too; wrap it in <select> tags.
class Category {
function getParent($id) {
return mysql_safe_query('SELECT parent.* FROM categories AS child, categories AS parent WHERE parent.id = child.parent_id AND child.id = %s LIMIT 1', $id);
}
function getChildren($id, $direct = false) {
if($direct) {
return mysql_safe_query('SELECT * FROM categories WHERE parent_id = %s ORDER BY left_val ASC', $id);
} else {
return mysql_safe_query('SELECT child.* FROM categories AS child, categories AS parent WHERE child.left_val >= parent.left_val AND child.right_val <= parent.right_val AND parent.id = %s ORDER BY child.left_val ASC', $id);
}
}
function insert($name, $parent_id) {
$result = mysql_safe_query('SELECT * FROM categories WHERE parent_id <=> %s AND name < %s ORDER BY name DESC LIMIT 1', $parent_id, $name);
if(mysql_num_rows($result) > 0) {
// insert between children
$row = mysql_fetch_assoc($result);
mysql_safe_query('UPDATE categories SET left_val = left_val + 2 WHERE left_val > %s', $row['right_val']);
mysql_safe_query('UPDATE categories SET right_val = right_val + 2 WHERE right_val > %s', $row['right_val']);
mysql_safe_query('INSERT INTO categories (parent_id, left_val, right_val, name) VALUES (%s, %s, %s, %s)',
$parent_id, $row['right_val'] + 1, $row['right_val'] + 2, $name);
} else {
$result = mysql_safe_query('SELECT * FROM categories WHERE id <=> %s LIMIT 1', $parent_id);
if(mysql_num_rows($result) > 0) {
// insert first child
$row = mysql_fetch_assoc($result);
mysql_safe_query('UPDATE categories SET left_val = left_val + 2 WHERE left_val > %s', $row['left_val']);
mysql_safe_query('UPDATE categories SET right_val = right_val + 2 WHERE right_val > %s', $row['left_val']);
mysql_safe_query('INSERT INTO categories (parent_id, left_val, right_val, name) VALUES (%s, %s, %s, %s)',
$parent_id, $row['left_val'] + 1, $row['left_val'] + 2, $name);
} else {
// insert at beginning of tree
mysql_safe_query('UPDATE categories SET left_val = left_val + 2, right_val = right_val + 2');
mysql_safe_query('INSERT INTO categories (parent_id, left_val, right_val, name) VALUES (%s, %s, %s, %s)',
null, 1, 2, $name);
}
}
}
function delete($id) {
$result = mysql_safe_query('SELECT * FROM categories WHERE id = %s LIMIT 1', $id);
$row = mysql_fetch_assoc($result);
mysql_safe_query('DELETE FROM categories WHERE id = %s LIMIT 1', $id);
mysql_safe_query('UPDATE categories SET parent_id = %s WHERE categories.parent_id = %s', $row['parent_id'], $id); // relink parent
mysql_safe_query('UPDATE categories SET left_val = left_val - 1, right_val = right_val - 1 WHERE left_val > %s AND right_val < %s', $row['left_val'], $row['right_val']); // update children
mysql_safe_query('UPDATE categories SET left_val = left_val - 2 WHERE left_val > %s', $row['right_val']); // update left values of nodes to right
mysql_safe_query('UPDATE categories SET right_val = right_val - 2 WHERE right_val > %s', $row['right_val']); // update right values of encompassing nodes and nodes to right
}
function incPostCount($id, $amount=1) {
$result = mysql_safe_query('SELECT * FROM categories WHERE id = %s', $id);
$row = mysql_fetch_assoc($result);
return mysql_safe_query('UPDATE categories SET num_posts = num_posts + %s WHERE left_val <= %s AND right_val >= %s',
$amount, $row['left_val'], $row['right_val']);
}
function decPostCount($id, $amount=1) {
return self::incPostCount($id, -$amount);
}
function getPath($id) {
$result = mysql_safe_query('SELECT * FROM categories WHERE id = %s', $id);
$row = mysql_fetch_assoc($result);
return mysql_safe_query('SELECT * FROM categories WHERE left_val <= %s AND right_val >= %s ORDER BY left_val ASC',
$row['left_val'], $row['right_val']);
}
function printOptions($selected=null, $format=null, $mult=null, $add=null) {
if(!isset($format)) $format = '<option value="%s" style="padding-left:%spx"%s>%s</option>';
if(!isset($mult)) $mult = 15;
if(!isset($add)) $add = 3;
$depth = 0;
$result = mysql_safe_query('SELECT * FROM categories ORDER BY categories.left_val ASC');
while($row = mysql_fetch_assoc($result)) {
if(isset($last)) {
if($row['left_val'] == $last['left_val'] + 1) {
++$depth;
$next_right = $last_right + 1;
} elseif($row['left_val'] > $last['right_val'] + 1) {
$levels = $row['left_val'] - $last['right_val'] - 1;
$depth -= $levels;
}
}
$last = $row;
if($row['id'] == $selected) $selected_str = ' selected="selected"';
else $selected_str = '';
echo sprintf($format, $row['id'], $depth*$mult+$add, $selected_str, $row['name'], $row['num_posts'], $depth);
}
}
function printTree($format=null) {
if(!isset($format)) $format = '<li><a href="index.php?cat=%s">%s</a> (%s)';
$depth = 0;
$result = mysql_safe_query('SELECT * FROM categories ORDER BY categories.left_val ASC');
echo '<ul>';
while($row = mysql_fetch_assoc($result)) {
if(isset($last)) {
if($row['left_val'] == $last['left_val'] + 1) {
echo '<ul>';
++$depth;
$next_right = $last_right + 1;
} elseif($row['left_val'] > $last['right_val'] + 1) {
$levels = $row['left_val'] - $last['right_val'] - 1;
echo str_repeat('</li></ul></li>', $levels);
$depth -= $levels;
} else {
echo '</li>';
}
}
$last = $row;
echo sprintf($format, $row['id'], $row['name'], $row['num_posts'], $depth);
}
echo str_repeat('</li></ul>', $depth+1);
}
function printAdminTree() {
self::printTree('<li><a href="index.php?cat=%s">%s</a> (<a href="category_delete.php?id=%1$s">Delete</a>)');
}
}
Please, please, please leave a comment if you’re actually reading this and not a bot scraping my content for your own blog… if that’s what you’re doing, this tutorial was found on ProgramAndDesign.com you jerk.
Hash/unhash HTML
May/090
Here’s a little class I wrote that lets you hash HTML and other things so that you can do some processing on just the text, and then unhash the HTML again.
{
static $hashes = array();
# hashes everything that matches $pattern and saves matches for later unhashing
function hash($text, $pattern) {
return preg_replace_callback($pattern, array(self,'push'), $text);
}
# hashes all html tags and saves them
function hash_html($html) {
return self::hash($html, '`<[^>]+>`');
}
# hashes and saves $value, returns key
function push($value) {
if(is_array($value)) $value = $value[0];
static $i = 0;
$key = "\x05".++$i."\x06";
self::$hashes[$key] = $value;
return $key;
}
# unhashes all saved values found in $text
function unhash($text) {
return str_replace(array_keys(self::$hashes), self::$hashes, $text);
}
function get($key) {
return self::$hashes[$key];
}
function clear() {
self::$hashes = array();
}
}
PHP string ends with
May/090
There’s a hundred ways to do this, but here’s the one I came up with. It doesn’t use regex’s so it should be pretty quick.
return substr($str, -strlen($suffix)) == $suffix;
}
function starts_with($str, $prefix) {
return substr($str, 0, strlen($prefix)) == $prefix;
}
For completeness, I added the corresponding starts_with function.
Random String
May/090
Just some functions for generating random strings in PHP.
$i = 0;
$str = '';
$randmax = strlen($chars)-1;
for($i=0; $i<$len; ++$i) {
$str .= $chars[mt_rand(0,$randmax)];
}
return $str;
}
function randkey($len=32) {
return randstr($len, '`1234567890-=qwertyuiop[]\\asdfghjkl;\'zxcvbnm,./ ~!@#$%^&*()_+{}|:"<>?');
}
randkey is good for generating salt strings and such, randstr is good for stuff like short URLs. Of course, you can pass in whatever characters you want.
Encode Array as String
May/090
I wanted to store an array in a cookie, so I wrote these two functions:
return base64_encode(serialize($data));
}
function decode_arr($data) {
return unserialize(base64_decode($data));
}
Base62 Encode
Apr/090
If you have large integers and you want to shrink them down in size for whatever reason, you can use this code. Should be easy enough to extend if you want even higher bases (just add a few more chars and increase the base).
// can't handle numbers larger than 2^31-1 = 2147483647
$str = '';
do {
$i = $val % $base;
$str = $chars[$i] . $str;
$val = ($val - $i) / $base;
} while($val > 0);
return $str;
}
function decode($str, $base=62, $chars='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') {
$len = strlen($str);
$val = 0;
$arr = array_flip(str_split($chars));
for($i = 0; $i < $len; ++$i) {
$val += $arr[$str[$i]] * pow($base, $len-$i-1);
}
return $val;
}
echo encode(2147483647); // outputs 2lkCB1