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Is there any way to add an increment value while imploding an array?
This is the piece of code I'd like to have the increment value:
$entries = '<ul class="repeatData"><li class="listEntry1">' . implode('</li><li class="listEntry'. $countme .'">', $data) . '</li></ul>';
I'd like somehow to make the variable $countme increment every time it implodes each array value, if this is even possible.
You cannot do this with implode, but look into applying an anonymous function to the array. You can probably do what you want with not much more code.
$entries = '<ul class="repeatData">';
$countme = 1;
array_walk($data, function ($element) use (&$entries, &$countme) {
$entries .= '<li class="listEntry'. $countme .'">'. $element . '</li>';
$countme++;
});
$entries .= "</ul>";
Explanation: I have written an anonymous function, told it about $entries and $counter (so it is a closure, in fact) so that it can modify them from inside its scope, and passed it to array_walk, which will apply it to all elements of the array.
There is no built in function for that. You have to write your own:
This function generalizes the problem and takes an array of glues and the data as arguments. You may refine it to fit more to your needs...
function custom_implode($glues, $pieces) {
$result = '';
while($piece = array_shift($pieces)) {
$result .= $piece;
$glue = array_shift($glues);
if(!empty($pieces)) {
$result .= $glue;
}
}
return $result;
}
Usage:
$glues = array();
for($i = 0; $i < $end; $i++) {
$glues []= '</li><li class="listEntry'. $i .'">';
}
echo custom_implode($glues, $data);
You can save the for loop which populates $glues if you customize the function a little bit more:
function custom_implode($start, $pieces) {
$result = '';
$counter = $start;
while($piece = array_shift($pieces)) {
$result .= $piece;
if(!empty($pieces)) {
$result .= '</li><li class="listEntry'. $counter .'">';
}
}
return $result;
}
To expand upon #ravloony's answer, you can use a mapping function with a counter to produce what you want, the following function could assist.
function implode_with_counter($glue, $array, $start, $pattern) {
$count = $start;
$str = "";
array_walk($array, function($value) use ($glue, $pattern, &$str, &$count) {
if (empty($str)) {
$str = $value;
} else {
$str = $str . preg_replace('/' . preg_quote($pattern, '/') . '/', $count, $glue) . $value;
$count++;
}
});
return $str;
}
Example use:
echo implode_with_counter(' ([count]) ', range(1,5), 1, '[count]');
// Output: 1 (1) 2 (2) 3 (3) 4 (4) 5
For your case:
$entries = '<ul class="repeatData"><li class="listEntry1">'
. implode_with_counter('</li><li class="listEntry[countme]">', $data, 2, '[countme]')
. '</li></ul>';
Update: Alternative
An alternative approach is to just implement a callback version of implode(), and provide a function. Which is a little more universally usable, than the pattern matching.
function implode_callback($callback, array $array) {
if (!is_callable($callback)) {
throw InvalidArgumentException("Argument 1 must be a callable function.");
}
$str = "";
$cIndex = 0;
foreach ($array as $cKey => $cValue) {
$str .= ($cIndex == 0 ? '' : $callback($cKey, $cValue, $cIndex)) . $cValue;
$cIndex++;
}
return $str;
}
Example use:
echo implode_callback(function($cKey, $cValue, $cIndex) {
return ' (' . $cIndex . ') ';
}, range(1,5));
// Output: 1 (1) 2 (2) 3 (3) 4 (4) 5
Your case:
$entries = '<ul class="repeatData"><li class="listEntry1">'
. implode_callback(function($cKey, $cValue, $cIndex) {
return '</li><li class="listEntry' . ($cIndex + 1) . '">';
}, $data)
. '</li></ul>';
No, implode doesn't work that way.
You will need to create your own function to do that.
You should also consider if this is what you really need. In both Javascript and CSS you can easily reference the n-th child of a node if you need to do that.
I need bit help as I am facing two issues.
Links without domain extension (.com, .net, ect) will be stored in
database as single words
Script allows for self shortening the shortner url which is a major
issue.
How can I
Check for domain extension else fail submit
and
Check if user is trying to shorten my own link and fail as well.
My code:
function remove_http($url)
{
$disallowed = array('http://', 'https://', 'http//', 'https//');
foreach($disallowed as $d) {
if(strpos($url, $d) === 0) {
return str_replace($d, '', $url);
}
}
return $url;
}
$url_to_shorten = get_magic_quotes_gpc() ? stripslashes(trim($_REQUEST['url'])) : trim($_REQUEST['url']);
if(!empty($url_to_shorten) || parse_url($url_to_shorten, PHP_URL_SCHEME) )
{
require('framework/core/config.xml.php');
// check if the URL has already been shortened
$already_shortened = mysql_result(mysql_query('SELECT id FROM ' . DB_TABLE. ' WHERE long_url="' . mysql_real_escape_string(remove_http($url_to_shorten)) . '"'), 0);
if(!empty($already_shortened))
{
// URL has already been shortened
$shortened_url = getShortenedURLFromID($already_shortened);
}
else
{
// URL not in database, insert
mysql_query('LOCK TABLES ' . DB_TABLE . ' WRITE;');
mysql_query('INSERT INTO ' . DB_TABLE . ' (long_url, created, creator) VALUES ("' . mysql_real_escape_string(remove_http($url_to_shorten)) . '", "' . time() . '", "' . mysql_real_escape_string($_SERVER['REMOTE_ADDR']) . '")');
$shortened_url = getShortenedURLFromID(mysql_insert_id());
mysql_query('UNLOCK TABLES');
}
echo BASE_HREF . $shortened_url;
}
function getShortenedURLFromID ($integer, $base = ALLOWED_CHARS)
{
$length = strlen($base);
while($integer > $length - 1)
{
$out = $base[fmod($integer, $length)] . $out;
$integer = floor( $integer / $length );
}
return $base[$integer] . $out;
}
I'm working on a project, and I've come across an issue that has me stumped. The code below is a class file and a test page to make sure it's working. It's for somebody else who is programming the site, otherwise I would code the JSON output differently. Basically, the person implementing it just has to pull a bunch of data (like below) from a database, and loop through, instantiating a class object for each result, and plugging each instance into an array, and passing the array to the printJson function, which will print the JSON string. Here is what I have:
Results.php
<?php
class Result
{
public $Category = NULL;
public $Title = NULL;
public $Price = NULL;
public function __construct($category, $title, $price)
{
$this->Category = $category;
$this->Title = $title;
$this->Price = $price;
}
public static function printJson($arrayOfResults)
{
$output = '{"results": [';
foreach ($arrayOfResults as $result)
{
$output += '{"category": "' . $result->Category . '",';
$output += '"title": "' . $result->Title . '",';
$output += '"price": "' . $result->Price . '",';
$output += '},';
}
$output = substr($output, 0, -1);
$output += ']}';
return $output;
}
}
?>
getResults.php
<?php
require_once('Result.php');
$res1 = new Result('food', 'Chicken Fingers', 5.95);
$res2 = new Result('food', 'Hamburger', 5.95);
$res3 = new Result('drink', 'Coke', 1);
$res4 = new Result('drink', 'Coffee', 2);
$res5 = new Result('food', 'Cheeseburger', 6.95);
$x = $_GET['x'];
if ($x == 1)
{
$array = array($res1);
echo Result::printJson($array);
}
if ($x == 2)
{
$array = array($res1, $res2);
echo Result::printJson($array);
}
if ($x == 3)
{
$array = array($res1, $res2, $res3);
echo Result::printJson($array);
}
if ($x == 5)
{
$array = array($res1, $res2, $res3, $res4, $res5);
echo Result::printJson($array);
}
?>
The end result is if I go to getResults.php?x=5, it will return $res1 thru $res5 (again, this is just to test, I would never do something like this in production) formatted as JSON. Right now, I get '0' outputted and I cannot for the life of me figure out why. Could my foreach loop not be written properly? Please, any help you could provide would be awesome!
It's because you're using + for concatenation rather than .:
$output .= '{"category": "' . $result->Category . '",';
$output .= '"title": "' . $result->Title . '",';
$output .= '"price": "' . $result->Price . '",';
$output .= '},';
But you should really not construct the JSON yourself, as it leads to a number of errors making for invalid JSON (trailing commas etc). Use something like this instead:
public static function printJson(array $arrayOfResults)
{
$results['results'] = array_map('get_object_vars', $arrayOfResults);
return json_encode($results);
}
I am currently making a homepage where logged in users can write comments. The comment string is first run through a function that str_replaces emoticons. After that I want it to exchange
[url=www.whatever.com]linktext[/url]
with:
<a href='www.whatever.com'>linktext</a>
The reason for this is that I want to strip the text for all the html code that isn't controlled by my comment code, in case some users decide to get creative-
and thought it would be best to use preg replace but the code I ended up with (Partially from reading about reg exp from my trusty "O reilly Sql and Php"-book and partially from the web) Is pretty bonkers, and most importantly, doesn't work.
Any help would be appreciated, thanks.
It's probably possible to exchange the entire code, not in 2 segments like I have done. Just decided on that getting 2 smaller parts to work first would be easier, and then merge them afterwards.
code:
function text_format($string)
{
$pattern="/([url=)+[a-zA-Z0-9]+(])+/";
$string=preg_replace($pattern, "/(<a href=\')+[a-zA-Z0-9]+(\'>)+/", $string);
$pattern="/([\/url])+/";
$string=preg_replace($pattern, "/(<\/a>)+/", $string);
return $string;
}
It looks like you're using something similar to BBCode. Why not use a BBCode parser, such as this one?
http://nbbc.sourceforge.net/
It also handles smilies, replacing them with images. If you use their test page, you will still see the text though, because they don't host the images and they set the alt-text to the smily.
I experimented a bit with the following:
function text_format($string)
{
return preg_replace('#\[url=([^\]]+)\]([^\[]*)\[/url\]#', '$2', $string);
}
However, one immediate fault with this is that if linktext is empty, there will be nothing between <a> and </a>. One way around it would be to do another pass with something like this:
preg_replace('##', '$1', $string);
Another option would be to use preg_replace_callback and put this logic inside your callback function.
Finally, this is obviously a common "problem" and has been solved many times by others, and if using a more mature open sourced solution is an option, I'd recommend looking for one.
#Lauri Lehtinen's answer is good for learning the idea behind the technique, but you shouldn't use it in practice because it would make your site extremely vulnerable to XSS attacks. Also, link spammers would appreciate the lack of rel="nofollow" on the generated links.
Instead, use something like:
<?php
// \author Daniel Trebbien
// \date 2010-06-22
// \par License
// Public Domain
$allowed_uri_schemes = array('http', 'https', 'ftp', 'ftps', 'irc', 'mailto');
/**
* Encodes a string in RFC 3986
*
* \see http://tools.ietf.org/html/rfc3986
*/
function encode_uri($str)
{
$str = urlencode('' . $str);
$search = array('%3A', '%2F', '%3F', '%23', '%5B', '%5D', '%40', '%21', '%24', '%26', '%27', '%28', '%29', '%2A', '%2B', '%2C', '%3B', '%3D', '%2E', '%7E');
$replace = array(':', '/', '?', '#', '[', ']', '#', '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=', '.', '~'); // gen-delims / sub-delims / unreserved
return str_ireplace($search, $replace, $str);
}
function url_preg_replace_callback($matches)
{
global $allowed_uri_schemes;
if (empty($matches[1]))
return $matches[0];
$href = trim($matches[1]);
if (($i = strpos($href, ':')) !== FALSE) {
if (strrpos($href, '/', $i) === FALSE) {
if (!in_array(strtolower(substr($href, 0, $i)), $allowed_uri_schemes))
return $matches[0];
}
}
// unescape `\]`, `\\\]`, `\\\\\]`, etc.
for ($j = strpos($href, '\\]'); $j !== FALSE; $j = strpos($href, '\\]', $j)) {
for ($i = $j - 2; $i >= 0 && $href[$i] == '\\' && $href[$i + 1] == '\\'; $i -= 2)
/* empty */;
$i += 2;
$h = '';
if ($i > 0)
$h = substr($href, 0, $i);
for ($numBackslashes = floor(($j - $i)/2); $numBackslashes > 0; --$numBackslashes)
$h .= '\\';
$h .= ']';
if (($j + 2) < strlen($href))
$h .= substr($href, $j + 2);
$href = $h;
$j = $i + floor(($j - $i)/2) + 1;
}
if (!empty($matches[2]))
$href .= str_replace('\\\\', '\\', $matches[2]);
if (empty($matches[3]))
$linkText = $href;
else {
$linkText = trim($matches[3]);
if (empty($linkText))
$linkText = $href;
}
$href = htmlspecialchars(encode_uri(htmlspecialchars_decode($href)));
return "$linkText";
}
function render($input)
{
$input = htmlspecialchars(strip_tags('' . $input));
$input = preg_replace_callback('~\[url=((?:[^\]]|(?<!\\\\)(?:\\\\\\\\)*\\\\\])*)((?<!\\\\)(?:\\\\\\\\)*)\]' . '((?:[^[]|\[(?!/)|\[/(?!u)|\[/u(?!r)|\[/ur(?!l)|\[/url(?!\]))*)' . '\[/url\]~i', 'url_preg_replace_callback', $input);
return $input;
}
which I believe is safe against XSS. This version has the added benefit that it is possible to write out links to URLs that contain ']'.
Evaluate this code with the following "test suite":
echo render('[url=http://www.bing.com/][[/[/u[/ur[/urlBing[/url]') . "\n";
echo render('[url=][/url]') . "\n";
echo render('[url=http://www.bing.com/][[/url]') . "\n";
echo render('[url=http://www.bing.com/][/[/url]') . "\n";
echo render('[url=http://www.bing.com/][/u[/url]') . "\n";
echo render('[url=http://www.bing.com/][/ur[/url]') . "\n";
echo render('[url=http://www.bing.com/][/url[/url]') . "\n";
echo render('[url=http://www.bing.com/][/url][/url]') . "\n";
echo render('[url= javascript: window.alert("hi")]click me[/url]') . "\n";
echo render('[url=#" onclick="window.alert(\'hi\')"]click me[/url]') . "\n";
echo render('[url=http://www.bing.com/] [/url]') . "\n";
echo render('[url=/?#[\\]#!$&\'()*+,;=.~] [/url]') . "\n"; // link text should be `/?#[]#!$&'()*+,;=.~`
echo render('[url=http://localhost/\\\\]d]abc[/url]') . "\n"; // href should be `http://localhost/%5C`, link text should be `d]abc`
echo render('[url=\\]][/url]') . "\n"; // link text should be `]`
echo render('[url=\\\\\\]][/url]') . "\n"; // link text should be `\]`
echo render('[url=\\\\\\\\\\]][/url]') . "\n"; // link text should be `\\]`
echo render('[url=a\\\\\\\\\\]bcde\\]fgh\\\\\\]ijklm][/url]') . "\n"; // link text should be `a\\]bcde]fgh\]ijklm`
Or, just look at the Codepad results.
As you can see, it works.
I often need to list items separated by comma, space or punctuation, addresses are a classic example (This is overkill for an address and is for the sake of an example!):
echo "L$level, $unit/$num $street, $suburb, $state $postcode, $country.";
//ouput: L2, 1/123 Cool St, Funky Town, ABC 2000, Australia.
As simple as it sounds, is there an easy way to "conditionally" add the custom separators between variables only if the variable exists? Is it necessary to check if each variable is set? So using the above, another address with less detail may output something like:
//L, / Cool St, , ABC , .
A slightly arduous way of checking would be to see if each variable is set and display the punctuation.
if($level){ echo "L$level, "; }
if($unit){ echo "$unit"; }
if($unit && $street){ echo "/"; }
if($street){ echo "$street, "; }
if($suburb){ echo "$suburb, "; }
//etc...
It would be good to have a function that could automatically do all the stripping/formatting etc:
somefunction("$unit/$num $street, $suburb, $state $postcode, $country.");
Another example is a simple csv list. I want to output x items separated by comma:
for($i=0; $i=<5; $i++;){ echo "$i,"; }
//output: 1,2,3,4,5,
In a loop for example, what's the best way of determining the last item of an array or the loop condition is met to not include a comma at the end of the list? One long way around this I've read of is to put a comma before an item, except the first entry something like:
$firstItem = true; //first item shouldn't have comma
for($i=0; $i=<5; $i++;){
if(!$firstItem){ echo ","; }
echo "$i";
$firstItem = false;
}
For your first example, you can use arrays in conjunction with a few of the array methods to get the desired result. For example:
echo join(', ', array_filter(array("L$level", join(' ', array_filter(array(join('/', array_filter(array($unit, $num))), $street))), $suburb, join(' ', array_filter(array($state, $postcode))), $country))) . '.';
This one-liner is quite complicated to read, so one can always wrap the array, array_filter and join calls into a separate method, and use that:
function merge($delimiter)
{
$args = func_get_args();
array_shift($args);
return join($delimiter, array_filter($args));
}
echo merge(', ', "L$level", merge(' ', merge('/', $unit, $num), $street), $suburb, merge(' ', $state, $postcode), $country) . '.';
You need the array_filter calls to remove the empty entries, otherwise the delimeters would still be printed out.
For your second example, add the items to an array, then use join to insert the delimeter:
$arr = array();
for($i=0; $i=<5; $i++)
{
$arr[] = $i;
}
echo(join(',', $arr));
While Phillip's answer addresses your question, I wanted to supplement it with the following blog post by Eric Lippert. Although his discussion is in c#, it applies to any programming language.
There's a simple solution to your second problem:
for($i=0; $i<=5; $i++)
$o .= "$i,";
echo chop($o, ',');
ok, take that! (but not too serious ^^)
<?php
function bothOrSingle($left, $infix, $right) {
return $left && $right ? $left . $infix . $right : ($left ? $left : ($right ? $right : null));
}
function leftOrNull($left, $postfix) {
return $left ? $left . $postfix : null;
}
function rightOrNull($prefix, $right) {
return $right ? $prefix . $right : null;
}
function joinargs() {
$args = func_get_args();
foreach ($args as $key => $arg)
if (!trim($arg))
unset($args[$key]);
$sep = array_shift($args);
return join($sep, $args);
}
$level = 2;
$unit = 1;
$num = 123;
$street = 'Cool St';
$suburb = 'Funky Town';
$state = 'ABC';
$postcode = 2000;
$country = 'Australia';
echo "\n" . '"' . joinargs(', ', rightOrNull('L', $level), bothOrSingle(bothOrSingle($unit, '/', $num), ' ', $street), bothOrSingle($state, ' ', $postcode), bothOrSingle($country, '', '.')) . '"';
// -> "L2, 1/123 Cool St, ABC 2000, Australia."
$level = '';
$unit = '';
$num = '';
$street = 'Cool St';
$suburb = '';
$state = 'ABC';
$postcode = '';
$country = '';
echo "\n" . '"' . joinargs(
', ',
leftOrNull(
joinargs(', ',
rightOrNull('L', $level),
bothOrSingle(bothOrSingle($unit, '/', $num), ' ', $street),
bothOrSingle($state, ' ', $postcode),
$country
),
'.'
)
) . '"';
// -> "Cool St, ABC."
$level = '';
$unit = '';
$num = '';
$street = '';
$suburb = '';
$state = '';
$postcode = '';
$country = '';
echo "\n" . '"' . joinargs(
', ',
leftOrNull(
joinargs(', ',
rightOrNull('L', $level),
bothOrSingle(bothOrSingle($unit, '/', $num), ' ', $street),
bothOrSingle($state, ' ', $postcode),
$country
),
'.'
)
) . '"';
// -> "" (even without the dot!)
?>
yes, i know - looks a bit like brainfuck.
Philip's solution is probably best when working with arrays (if you don't have to filter out empty values), but if you can't use the array functions--for instance, when dealing with query results returned from mysqli_fetch_object()--then one solution is just a simple if statement:
$list = '';
$row=mysqli_fetch_object($result);
do {
$list .= (empty($list) ? $row->col : ", {$row->col}");
} while ($row=mysqli_fetch_object($result));
Or, alternatively:
do {
if (isset($list)) {
$list .= ", {$row->col}";
} else $list = $row->col;
} while ($row=mysqli_fetch_object($result));
To build a list and filter out empty values, I would write a custom function:
function makeList() {
$args = array_filter(func_get_args()); // as per Jon Benedicto's answer
foreach ($args as $item) {
if (isset($list)) {
$list .= ", $item";
} else {
$list = $item;
}
}
if (isset($list)) {
return $list;
} else return '';
}
Then you can call it like so:
$unitnum = implode('/',array_filter(array($unit,$num)));
if ($unitnum || $street) {
$streetaddress = trim("$unitnum $street");
} else $streetaddress = '';
if ($level) {
$level = "L$level";
}
echo makeList($level, $streetaddress, $suburb, $state $postcode, $country).'.';
I always find that its both faster and easier to use the language's array methods. For instance, in PHP:
<?php
echo join(',', array('L'.$level, $unit.'/'.$num,
$street, $suburb, $state, $postcode, $country));
Just take out the last comma, i.e replace it with nothing.
$string1 = "L$level, $unit/$num $street, $suburb, $state $postcode, $country.";
$string1 = eregi_replace(", \.$", "\.", $string1);
echo $string1;
This will do the work.
<?php
$level = 'foo';
$street = 'bar';
$num = 'num';
$unit = '';
// #1: unreadable and unelegant, with arrays
$values = array();
$values[] = $level ? 'L' . $level : null;
// not very readable ...
$values[] = $unit && $num ? $unit . '/' . $num : ($unit ? $unit : ($num ? $num : null));
$values[] = $street ? $street : null;
echo join(',', $values);
// #2: or, even more unreadable and unelegant, with string concenation
echo trim(
($level ? 'L' . $level . ', ' : '') .
($unit && $num ? $unit . '/' . $num . ', ' : ($unit ? $unit . ', ' : ($num ? $num . ', ': '')) .
($street ? $street . ', ': '')), ' ,');
// #3: hey, i didn't even know that worked (roughly the same as #1):
echo join(', ', array(
$level ? 'L' . $level : null,
$unit && $num ? $unit . '/' . $num : ($unit ? $unit : ($num ? $num : null)),
$street ? $street : null
));
?>