How to create a .webp image in PHP

WebP:

    WebP is an image file type that was created in 2010 and is created by Google. This image format provides lossless and lossy compression to images on the server. Big social media websites are using WebP image process are Google, Facebook and EBay.
 
  WebP images natively supporting to the following browsers are Chrome, Opera, Opera Mini, Android Browser and Chrome for Android browsers only. It is not supported any other browsers like Firefox, IE and Safari,etc.

 

    WebP lossless image files are 26% smaller than PNGs.
    WebP lossy images files are 25-34% smaller than JPEG images at equivalent SSIM index.
    WebP supports lossless transparency (also known as alpha channel) with just 22% more bytes.

WebP images creating process in php:

you can use following php commands,to get the webp images

$imgName     =   "codingslovers.jpg";
$webPName   =   "codingslovers.webp";

Syntax:

 cwebp [quality qualitypercentage] [source image] -o [destination]

exec("cwebp -q 0 ".$imgName." -o ".$webPName." ");

Another Method:

exec("convert -colorspace RGB ".$imgName." ".$webPName . " ");

Exec : executes the given command in php

http://php.net/manual/en/function.exec.php

Advantages of WebP:

Smaller file size
Different compression algorithm
Smoother color gradations
Alpha channel mask

Disadvantages of WebP:

Weak browser support
Artifacting has plastic appearance
Poor exporting interface

Browserwise WebP Performance:

  WebP Supporting Browsers

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Abstract Class in Php

Abstract class in PHP:

•     Abstract Class  contains only declare the method's signature, they can't define the implementation.

•     Abstraction class are defined using the keyword abstract .
•     Abstract Class is not possible to implement multiple inheritance.
•     Latest version of PHP 5 has introduces abstract classes and methods.
•     Classes defined as abstract , we are unable to create the object ( may not instantiated ).

•     we can extend the Abstract class, by using extends operator.
•     we can inherit only one abstract class at one time extending.
•     Any class that contains one abstract method must also be declare as abstract.
•     All methods marked as abstract in the parent's class, declaration must be defined by the   child.
•     Additionally, these methods must be defined with the same (or a less restricted) visibility           (Public,Protected & private).
•     Type hint & number of parameter must be match between parent & child class.

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JSON with Php, javascript and ajax

What is JSON?

JavaScript Object Notation (JSON) is a lightweight data-interchange format inspired by the object literals of JavaScript. 

JSON values can consist of:

•   objects (collections of name-value pairs)
•   arrays (ordered lists of values)
•   strings (in double quotes)
•   numbers
•   true, false, or null

JSON is language independent.

JSON with PHP?

   After PHP Version 5.2.0, JSON extension is decodes and encodes functionalities as default.

• Json_encode     - returns the JSON representation of values
• Json_decode     - Decodes the JSON String
• Json_last_error - Returns the last error occured.

JSON Syntax and Rules?

   JSON syntax is derived from JavaScript object notation syntax:

• Data is in name/value pairs
• Data is separated by commas
• Curly braces hold objects
• Square brackets hold arrays

JSON Example

    This example is simple phone number validation and once phone number has validated , it will be sent this php page, there we are using the json format related encode data.

Html Page:
  

<html>
<head>
<title>JSON Example in Php</title>
<script src="js/jquery-1.11.0.min.js"></script>
</head>
<body>
<h1>Json Basic Example</h1>
<form name="phone-form" method="post" onsubmit="return validation();">
 <input type="text" name="phone" id="phone" value="" >
 <input type="submit" value="submit" >
</form>
<div id="outputDisplay"></div>

Javascript Function

<script>
function validation(value){ 
 //Phone Number Validations
 var phone   = $('#phone').val();
 var specialDigitPattern  = /[~`!@#\$%\^&\*()\-_\+=|\\{}\[\]:;"'<>,\?\/\.0123456789]/;
 //var mailvalidateregex  = /^([a-zA-Z0-9_.+-])+\@(([a-zA-Z0-9-])+\.)+([a-zA-Z0-9]{2,4})+$/;  email validation
 if(phone == ""){
  alert("Please enter the phone ");
  return false;
 }else if(isNaN(phone)){
  alert('Please Enter Valid Phone Number');
  return false;
 }
 
 var postdata  = 'phone='+phone;
 var url   = 'testphone.php?phone='+phone;
 
 $.ajax({
  type  : "POST",
  url   : url, 
  data  : postdata,
  dataType : "json",
  success  : phonestatus_check,
 });
 return false;
}

function phonestatus_check(response){
 if(response.status == 1){
  alert('success');
  $("#outputDisplay").css("color","green");
  $("#outputDisplay").html(response.message);
 }else{
  alert('failure');
  return false;
 }
}
//ends
</script>

Php Page:

<?php
 if(isset($_POST['phone'])){
  $phonenumber = $_POST['phone'];
  $responsearray = array();$responsestatus = '1';
  if($responsestatus == 1){
      $responsearray = array('status' => 1,'message'=> 'Thanks for submitting the Phone Number');
  }else{
   $responsearray = array('status' => 0,'message'=> 'failure');
  }
  echo json_encode($responsearray);
  /* $json = json_encode($responsearray);
  if($_GET['jsoncallback'])
   exit("{$_GET['jsoncallback']}($json)"); */
 }
?>

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413 “Request Entity Too Large” error with uploading a file

Nginx: 413 Request Entity Too Large Error and Solution

  My application is running nginx as a frond end to php based Apache server. My applicatio lets user upload images upto 2MB in size. When users trying to upload 1.5MB+ size image file using nginx reverse proxy, they are getting the following error on screen:

    Nginx 413 Request Entity Too Large

You need to configure both nginx and php to allow upload size.

Nginx configuration:

The client_max_body_size directive assigns the maximum accepted body size of client 
 request, indicated by the line Content-Length in the header of request.

If size is greater the given one, then the client gets the error "Request Entity Too Large" 
(413). To fix this issue edit your nginx.conf.
  
Open the Terminal or login to the remote server using ssh client. 
Type the following command to edit your nginx.conf using a text editor such as vi or joe:

 

# vi /etc/nginx/nginx.conf
 

OR 

# vi /usr/local/nginx/conf/nginx.conf
Add the following line to http or server or location context to increase 
 the size limit 
 in nginx.conf, enter:

# set client body size to 2M #
client_max_body_size 2M;
 

Save and close the file. Reload the nginx webserver, enter:
# /usr/local/nginx/sbin/nginx -s reload
OR
# /sbin/nginx -s reload
OR use the following on RHEL/CentOS/Debian/Ubuntu Linux:
# service nginx reload 

PHP configuration (optional):



Your php installation also put limits on upload file size. 

Edit php.ini and set the following directives

;This sets the maximum amount of memory in bytes that a script is allowed 

to allocate
memory_limit = 32M
 
;The maximum size of an uploaded file.
upload_max_filesize = 2M
 
;Sets max size of post data allowed.This setting also affects file upload.

To upload large files, this value must be larger than upload_max_filesize
post_max_size = 3M
 

Save and close the file. Make sure you reload/restart back-end apache or 

nginx web server as per your setup

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