7 Super Useful PHP Code Snippets_PHP Tutorial

1. Super simple page caching
If your project is not based on a CMS system or framework, it will be very practical to build a simple caching system. The code below is very simple, but it can actually solve the problem for small websites.

Copy code The code is as follows:

// define the path and name of cached file
$cachefile = 'cached-files/'.date('M-d-Y').'.php';
// define how long we want to keep the file in seconds. I set mine to 5 hours.
$cachetime = 18000;
// Check if the cached file is still fresh. If it is, serve it up and exit.
if (file_exists($cachefile) && time() - $cachetime < ; filemtime($cachefile)) {
include($cachefile);
exit;
}
// if there is either no file OR the file to too old, render the page and capture the HTML.
ob_start();
?>

output all your html here. / We're done! Save the cached content to a file
$fp = fopen($cachefile, 'w');
fwrite($fp, ob_get_contents());
fclose($fp) ;
// finally send browser output
ob_end_flush();
?>


Click here for details: http://wesbos.com/simple-php- page-caching-technique/

2. Calculate distance in PHP
This is a very useful distance calculation function that uses latitude and longitude to calculate the distance from point A to point B. This function can return distance in three unit types: miles, kilometers, and nautical miles.



Copy code

The code is as follows: function distance($lat1, $lon1, $lat2, $lon2, $unit) {

$theta = $lon1 - $lon2;

$dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad( $lat2)) * cos(deg2rad($theta));
$dist = acos($dist);
$dist = rad2deg($dist);
$miles = $dist * 60 * 1.1515 ;
$unit = strtoupper($unit);

if ($unit == "K") {
return ($miles * 1.609344);
} else if ($unit == "N") {
return ($miles * 0.8684);
} else {
return $miles;
}
}


How to use :

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The code is as follows: echo distance(32.9697, -96.80322, 29.46786, -98.53506, "k") ." kilometers";

Click here to view details: http://www.phpsnippets.info/calculate-distances-in-php

3. Convert seconds to Time (year, month, day, hour...)
This useful function can convert events represented by seconds into time formats such as year, month, day, hour, etc.



Copy code

The code is as follows: function Sec2Time($time){

if(is_numeric($time)) {

$value = array(
"years" => 0, "days" => 0, "hours" => 0,
"minutes" => 0, "seconds" => 0,
);
if($time >= 31556926){
$value["years"] = floor($time/31556926);
$time = ($ time%31556926);
}
if($time >= 86400){
$value["days"] = floor($time/86400);
$time = ($time %86400);
}
if($time >= 3600){
$value["hours"] = floor($time/3600);
$time = ($time% 3600);
}
if($time >= 60){
$value["minutes"] = floor($time/60);
$time = ($time%60 );
}
$value["seconds"] = floor($time);
return (array) $value;
}else{
return (bool) FALSE;
}
}


Click here to view details: http://ckorp.net/sec2time.php

4. Force download of files
Some types such as mp3 files are usually played or used directly in the client browser. If you want them to be forced to download, that's no problem. You can use the following code:



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The code is as follows: function downloadFile($file){

$file_name = $file;

$mime = 'application/force-download';
header('Pragma: public'); // required
header('Expires: 0'); // no cache
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Cache-Control: private',false);
header('Content- Type: '.$mime);
header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
header('Content-Transfer-Encoding: binary' );
header('Connection: close');
readfile($file_name); // push it out
exit();
}


Click here to view details: Credit: Alessio Delmonti

5. Use Google API to obtain current weather information
Want to know today’s weather? This code will tell you that in just 3 lines of code. You just need to replace ADDRESS with the city you want.

Copy code The code is as follows:

$xml = simplexml_load_file('http://www.google.com/ig/ api?weather=ADDRESS');
$information = $xml->xpath("/xml_api_reply/weather/current_conditions/condition");
echo $information[0]->attributes();

Click here to view details: http://ortanotes.tumblr.com/post/200469319/current-weather-in-3-lines-of-php

6. Obtain Latitude and longitude of an address
With the popularity of Google Maps API, developers often need to obtain the longitude and latitude of a specific location. This very useful function takes an address as a parameter and returns an array containing longitude and latitude data.

Copy code The code is as follows:

function getLatLong($address){
if (!is_string($address) )die("All Addresses must be passed as a string");
$_url = sprintf('http://maps.google.com/maps?output=js&q=%s',rawurlencode($address)) ;
$_result = false;
if($_result = file_get_contents($_url)) {
if(strpos($_result,'errortips') > 1 || strpos($_result,'Did you mean:') !== false) return false;
preg_match('!center:s*{lat:s*(-?d+.d+),lng:s*(-?d+.d+)}! U', $_result, $_match);
$_coords['lat'] = $_match[1];
$_coords['long'] = $_match[2];
}
return $_coords;
}

Click here to view details: http://snipplr.com/view.php?codeview&id=47806

7. Use PHP and Google gets the favicon icon of the domain name
Some websites or web applications need to use favicon icons from other websites. It's easy to do it using Google and PHP, but the premise is that Google won't reset the connection!

Copy code The code is as follows:

function get_favicon($url){
$url = str_replace("http: //",'',$url);
return "http://www.google.com/s2/favicons?domain=".$url;
}

Click here to view details: http://snipplr.com/view.php?codeview&id=45928

http://www.bkjia.com/PHPjc/323856.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/323856.htmlTechArticle1. Super simple page cache. If your project is not based on a CMS system or framework, create a simple cache. The system will be very practical. The code below is very simple, but for small...