7 Super Useful PHP Code Snippets_PHP Tutorial

A good programmer is one who can come up with key codes at critical times. In this article, Mango Station has collected some key codes such as these, which are useful for programming.

1. Super simple page caching

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

<?php // 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.

<?php // 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 to view 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.

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:

echo distance(32.9697, -96.80322, 29.46786, -98.53506, "k")." kilometers";

Click here for 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.

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. Forced file download

Some files such as mp3 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:

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 for 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.

$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 for details: http://ortanotes.tumblr.com/post/200469319/current-weather-in-3-lines-of-php

6. Get the latitude and longitude of an address

With the popularity of the 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.

___FCKpd___6

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

7. Use PHP and Google to get the favicon icon of the domain name

Some websites or web applications require the use of 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!

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

Reference: 10 super useful PHP snippets

http://www.bkjia.com/PHPjc/363929.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/363929.htmlTechArticleA good programmer is one who can get the key code at critical times. In this article, Mango Station has collected some key codes such as these, which are useful for programming. 1. Super simple page slowdown...