Display Other Texts rather then English using PHP MySQL

When we want to display and store the data other than ENGLISH using PHP.

Below is the code used to save and retrieve the data in PHP.

mysql_set_charset('utf8',$db_connect);

where $db_connect is the "MySQL Host" connection handler. You can see the example below for the connection handler.


<?php
$db_connect = mysql_connect(HOST_NAME,USERNAME,PASSWORD);
mysql_set_charset('utf8',$db_connect);
?>

By using the above, we can store and retrieve the data in different languages like Telugu, French, Hindi, German and many.

Note: And also a major note we need to be keep in mind, when we try to retrieve the same UTF-8 converted data using AJAX. We should not use "mysql_set_charset" as AJAX by default sets the content as "UTF-8" 

Disable Back Button using Javascript

User tries to use back button for most of the applications and it is valid, but few of the cases is required to disable the back button and also restrict the user.

It would be very useful when the user is on payment page. Below is the code to disable the back button in Browser.

var currentURL = window.location.pathname + window.location.search;

 history.pushState(null, null, currentURL);

 window.addEventListener('popstate', function(event) {

  history.pushState(null, null, currentURL);

 });

It works in all major browsers

Trigger onchange event manually using Javascript

Below is the code to trigger onchange event for an element using javascript.

Usage of the method can be, when we want to call the onchange event on page loads or on by changing the text box value for other textbox.


if(document.fireEvent) {
    document.getElementById("myElement").fireEvent('onchange');
} else {
    var event = document.createEvent("HTMLEvents");
    event.initEvent("change",true,false);

    document.getElementById("myElement").dispatchEvent(event);
}

Whereas in jQuery, we can simply call the below method.

jQuery('myElement').change();

Javascript: trim function support in all browsers

In Javascript, when we want to remove spaces in a string, we would be using trim function which is supported in all major browsers. See below code to use trim function in Javascript.

var str = "     message to trim    ";
document.write(str.trim());  // this code will prints as message to trim in the body.

But the above trim() function doesnot support in IE. To support the same functionality in IE too, add the below code to work as expected.

if (typeof String.prototype.trim !== "function") {
    String.prototype.trim = function () {
        return this.replace(/^\s+|\s+$/g, "")
    }
}

Restrict image access from browser using HTACCESS

 When we want to restrict the image access from the browser other than the page, add the below code in htaccess file to apply.


RewriteEngine on 
RewriteCond %{HTTP_REFERER} !^http://(www\.)?localhost [NC] 
RewriteCond %{HTTP_REFERER} !^http://(www\.)?localhost.*$ [NC] 
RewriteRule \.(gif|jpg|png)$ - [F]

localhost need to be replaced by the domain name where the application is hosted. 

NOTE: Above code works in Apache (LINUX) not in windows

Redirect to maintenance page using HTACCESS

 Redirecting the whole site to maintenance page using HTACCESS

RewriteEngine On
RewriteBase /
RewriteCond %{REMOTE_ADDR} !^111\.11\.1\.11
RewriteCond %{REQUEST_URI} !^/maintenance\.html$
RewriteRule ^(.*)$ http://www.domainname.com/maintenance.html [R=307,L]


Rewrite condition mentioned is to stop the redirection for that particular domain.

RewriteCond %{REMOTE_ADDR} !^111\.11\.1\.11

"maintenance.html" is the page where you want to redirect the website.

Value of CKeditor using Javascript

To get the value of the CKeditor content using Javascript or jQuery. We need to use the below syntax.

CKEDITOR.instances['article_long_desc'].getData().length => It provides the length of the content in the editor

CKEDITOR.instances['article_long_desc'].getData() => It retrieves the value of the Textarea


Where "article_long_desc" is the textarea name

Random values from an Array using php

Below is the function to pick random values from an existing array

function array_pick_random($arr, $number = 1) {
    shuffle($arr);
   
    $r = array();
    for ($i = 0; $i < $number; $i++) {
        $r[] = $arr[$i];
    }
    return $number == 1 ? $r[0] : $r;
}

In the above function '$arr' is the Array which we want to get the random values.

'$number' is the number of array elements need to return.

Function returns an array if '$number' contains more than 1.

ajax with cross domain

We may worked with jQuery ajax in many cases but when we try to use jQuery AJAX to get the data from other domain, we need to use "crossDomain" & set it to true.

Let us consider the basic jQuery AJAX within the domain.

$.ajax({
            url: "show_users.php",
            data: {data1:"val1", data2="val2"},
            type:'POST',
            success: function(res)
            {
                $('#element_name').html(res);
            },
            error: function (){alert('something went wrong');}
});

Above is the AJAX request within the domain & just we are passing the data to the page "show_users.php" with two values. As it is simple AJAX request, it works fine.

But when we work with cross domains (i.e. AJAX request to other domain from our domain) we need to rewrite the jQuery AJAX as below.

$.ajax({
            url: "http://domain.com/show_users.php",
            data: {data1:"val1", data2="val2"},
            type:'POST',
            crossDomain: true,
            success: function(res)
            {
                $('#element_name').html(res);
            },
            error: function (){alert('something went wrong');}
});

We need to use "crossDomain" & set it to TRUE & in the domain.com show_users.php page we need to set an header as below.

header('Access-Control-Allow-Origin: *');

We can set the "Access-Control-Allow-Origin" with only one IP address or '*' if it is not limited to single IP address

Verify whether HTML object has the event using javascript or jQuery

We would be using multiple events or plugins to get our requirement done using jQuery.

While adding them we may not know whether the plugin is activated or not that gives error to the browser if it does not initiate and stops the next line of scripts in jQuery which we should not be doing. 

To get rid of this, we can use jQuery hasOwnProperty which tells whether the HTML object has the event which we are checking for.

Below is the sample code:

Consider we have included the CKEDITOR in the script and it applies for the textareas.

<html>

<head>

<script type="text/javascript" src="ckeditor.js">

<title>Test Object Event Existence</title>

</head>

<body>

<ul>

     <li>First name: <input type="text" name="fname" /> </li>

     <li>Last name: <input type="text" name="lname" /> </li>

     <li>Address: <textarea name="address" id="address" ></textarea></li>

</ul>

</body>

</html>

For the above script, to check whether the textareas has CKEDITOR or not we can check as below

$('#address').hasOwnProperty('CKEDITOR') 

If it exists it returns true else returns false.

Decode html entities using javascript

Below is the code to decode the html entities using javascript rather than the Server side scripting

function decodeEntities(input) {
    var y = document.createElement('textarea');
    y.innerHTML = input;
    return y.value;
}

Above function just receives the html values like below

var str = "<p>Hello World<br />This is the test message";

When we pass the above HTML string to the function it returns as below,

calling the JAVASCRIPT function 

decodeEntities(str)

Output is: "&lt;p&gt;Hello World&lt;br/&gt;This is the test message";

Disable right click in a page using javascript

When we want to restrict the right click of the mouse in some of the pages, need to add the below code in the <head> </head> tag within the JAVASCRIPT.

<script type="text/javascript">
var message="Sorry, Right Click has been disabled";
        function clickIE() {if (document.all) {window.console.log(message);return false;}}
       
       function clickNS(e) {
if (document.layers||(document.getElementById&&!document.all)) {
       if (e.which==2||e.which==3) {window.console.log(message);return false;}
}
}
        if (document.layers)
        {document.captureEvents(Event.MOUSEDOWN);document.onmousedown=clickNS;}
        else{document.onmouseup=clickNS;document.oncontextmenu=clickIE;}
        document.oncontextmenu=new Function("return false")

</script>

how to select all options in multi select dropdown using jquery

When we use multi select drop down, we may consider the feature for selecting all and deselect all option for the respective Multi Select box.

Using jQuery, we can easily do the select all and deselect all option for the dropdown.

Below is the code to select all using jQuery

HTML
<select name="education" id="education" multiple="multiple">
       <option value="1">Under Graduate</option>
       <option value="2">Graduate</option>
       <option value="3">Post Graduate</option>
       <option value="4">Pursuing Graduation</option>  
</select>

$('#education').find('option').attr('selected','selected');

Where 'education' is the id for the multi select & we are adding the attribute selected to get selected.

To deselect all using jQuery.

$('#education').find('option').removeAttr('selected','selected');

Basic UNIX commands

Below are the basic unix commands which may help you while using PUTTY to access the server. Move, copy, view the pages from folder to other destination. All other basic stuff syntax are given below


If there are images in this attachment, they will not be displayed.  Download the original attachment
Unix Basic Commands

Copy:

cp sorce_file target_file  :copies only if the files are in current direc

cp -r sor_DIR target_dir (to copy directories)

Move/Rename;

mv file1 file2

mv -i f1 f2 (asks for permision to move or not)

Remove:

rm filename

rm -r file (to remove directory structure)

rm -i file ( asks for permision to move or not)

view:

cat filename ( to view the complete file content)

To extract or unzip files:

unzip file ( extracts file to current dir)

To uncompress

uncompress filename

To compress

compress filename

To change directory

cd path

to list files in current dir

ls

ls -l (long list of files : gives acess permision,creation date..etc)

    -a(list all files satarting with a " .")

to make a dir

mkdir name or md name

to remove

rmdir dir_name

to clear the screen

clear (clears the windoe or terminal)

help commands

man <comd name> (displays the mannual page)

whatis <cammnd> (gives description)

date (to dispaly the date)

to count the words

wc filename (gives lines,words,characters

wc -l file (only lines)

wc -c file(only characters)

wc -w file(onbly words)

df ( displays the amount of free space)

grep (search a file for matching pattern)

grep [optioln]<regularExpression filename

eg: grep [a-z]*.c filename

Upload huge files in PHP

When we try to upload huge files using PHP, we face many issues to upload. One of them might be the php_value upload_max_filesize which is by default 2M in php.ini

Still we may have other issues which we need to do fix them. Below are the steps we need to add in htaccess to fix the large file uploads.

php_value upload_max_filesize 10M

php_value post_max_size 64M

php_value max_execution_time 300

javascript validation for file upload

Below is the article for adding javascript validation (or) jquery validation for a file upload that makes our life easier whether the file upload is a valid type or not.


if($('#upload_file').val() != '')
{
        var _validFileExtensions = [".jpg", ".jpeg", ".bmp", ".gif", ".png"]; // Can change the extensions if we need for doc type or something else
        if($('#upload_file').val() != '')
        {
            var sFileName = $('#upload_file').val();
            var blnValid = false;
            for (var j = 0; j < _validFileExtensions.length; j++)
            {
                var sCurExtension = _validFileExtensions[j];
                if (sFileName.substr(sFileName.length - sCurExtension.length, sCurExtension.length).toLowerCase() == sCurExtension.toLowerCase()) {
                    blnValid = true;
                    break;
                }
            }
            if(!blnValid)
            {
               alert("Sorry, " + sFileName + " is invalid, allowed extensions are: " + _validFileExtensions.join(", "));
                $('#upload_file').focus();
                return false;
            }
        }
 }

Generate random code using PHP

Below is the function to generate a random code(alpha-numeric) using PHP. We can use the below function for generating a coupon code (or) verification code (or) affiliate code for the people.

function generate_random_code( $size )
{
        $list_chars = array_merge(range('A','Z'), range(0,9));
      
        $referal_code = '';
      
        for($i=0;$i<=$size;$i++)
        {
            $referal_code .= $list_chars[mt_rand(0, count($list_chars)-1)];
        }
      
        return $referal_code;
      
}

$size  => Length of the random code to be generated. 

Calculate time difference using PHP

 function get_time_difference_php($created_time)

 {

        date_default_timezone_set('Asia/Calcutta'); //Change as per your default time

        $str = strtotime($created_time);

        $today = strtotime(date('Y-m-d H:i:s'));

        

        // It returns the time difference in Seconds...

        $time_differnce = $today-$str;

        

        // To Calculate the time difference in Years...

        $years = 60*60*24*365;

        

        // To Calculate the time difference in Months...

        $months = 60*60*24*30;

        

        // To Calculate the time difference in Days...

        $days = 60*60*24;

        

        // To Calculate the time difference in Hours...

        $hours = 60*60;

        

        // To Calculate the time difference in Minutes...

        $minutes = 60;

        if(intval($time_differnce/$years) > 1)

        {

            return intval($time_differnce/$years)." years ago";

        }else if(intval($time_differnce/$years) > 0)

        {

            return intval($time_differnce/$years)." year ago";

        }else if(intval($time_differnce/$months) > 1)

        {

            return intval($time_differnce/$months)." months ago";

        }else if(intval(($time_differnce/$months)) > 0)

        {

            return intval(($time_differnce/$months))." month ago";

        }else if(intval(($time_differnce/$days)) > 1)

        {

            return intval(($time_differnce/$days))." days ago";

        }else if (intval(($time_differnce/$days)) > 0) 

        {

            return intval(($time_differnce/$days))." day ago";

        }else if (intval(($time_differnce/$hours)) > 1) 

        {

            return intval(($time_differnce/$hours))." hours ago";

        }else if (intval(($time_differnce/$hours)) > 0) 

        {

            return intval(($time_differnce/$hours))." hour ago";

        }else if (intval(($time_differnce/$minutes)) > 1) 

        {

            return intval(($time_differnce/$minutes))." minutes ago";

        }else if (intval(($time_differnce/$minutes)) > 0) 

        {

            return intval(($time_differnce/$minutes))." minute ago";

        }else if (intval(($time_differnce)) > 1) 

        {

            return intval(($time_differnce))." seconds ago";

        }else

        {

            return "few seconds ago";

        }

  }

Difference between current date and past date using MySQL

Below is the function to get the time difference between Current date and the past date using MySQL. Mainly it can be used where we want to display the time gap between the registration of the user.

function getTimeDifference($created_since)

{

            $datediffquery = mysql_query  ("SELECT CASE WHEN TIMESTAMPDIFF(YEAR ,'".$created_since."', NOW()) > 1 THEN CONCAT(TIMESTAMPDIFF(YEAR ,'".$created_since."', NOW()), ' years ago')

                                                WHEN TIMESTAMPDIFF(YEAR ,'". $created_since."', NOW()) > 0 THEN CONCAT(TIMESTAMPDIFF(YEAR ,'". $created_since ."', NOW()), ' year ago')

                                                WHEN TIMESTAMPDIFF(MONTH ,'".$created_since."', NOW()) > 1 THEN CONCAT(TIMESTAMPDIFF(MONTH ,'".$created_since."', NOW()), ' months ago')

                                                WHEN TIMESTAMPDIFF(MONTH ,'".$created_since."', NOW()) > 0 THEN CONCAT(TIMESTAMPDIFF(MONTH ,'".$created_since."', NOW()), ' month ago')

                                                WHEN TIMESTAMPDIFF(DAY ,'".$created_since."', NOW()) > 1 THEN CONCAT(TIMESTAMPDIFF(DAY ,'".$created_since."', NOW()), ' days ago')

                                                WHEN TIMESTAMPDIFF(DAY ,'".$created_since."', NOW()) > 0 THEN CONCAT(TIMESTAMPDIFF(DAY ,'".$created_since."', NOW()), ' day ago')

                                                WHEN TIMESTAMPDIFF(HOUR ,'".$created_since."', NOW()) > 1 THEN CONCAT(TIMESTAMPDIFF(HOUR ,'".$created_since."', NOW()), ' hours ago')

                                                WHEN TIMESTAMPDIFF(HOUR ,'".$created_since."', NOW()) > 0 THEN CONCAT(TIMESTAMPDIFF(HOUR ,'".$created_since."', NOW()), ' hour ago')

                                                WHEN TIMESTAMPDIFF(MINUTE ,'".$created_since."', NOW()) > 1 THEN CONCAT(TIMESTAMPDIFF(MINUTE ,'".$created_since."', NOW()), ' minutes ago')

                                                WHEN TIMESTAMPDIFF(MINUTE ,'".$created_since."', NOW()) > 0 THEN CONCAT(TIMESTAMPDIFF(MINUTE ,'".$created_since."', NOW()), ' minute ago')

                                                WHEN TIMESTAMPDIFF(SECOND ,'".$created_since."', NOW()) > 1 THEN CONCAT(TIMESTAMPDIFF(SECOND ,'".$created_since."', NOW()), ' seconds ago')

                                            END

                                        AS total_days");

            

            $row = mysql_fetch_assoc($datediffquery);

            

            return $row['total_days'];

        }

Calculate time difference between two dates using PHP

Below is the PHP function to calculate the time difference between current date and the given date.

It will returns in Seconds, minutes, months (or) years based on the time difference.

And it can be used to calculate the time difference between two dates by changing the $today with the date which you want to pass.

function get_time_difference_php($created_time)

    {

        date_default_timezone_set('Asia/Calcutta');

        $str = strtotime($created_time);

        $today = strtotime(date('Y-m-d H:i:s'));

        

        // It returns the time difference in Seconds...

        $time_differnce = $today-$str;

        

        // To Calculate the time difference in Years...

        $years = 60*60*24*365;

        

        // To Calculate the time difference in Months...

        $months = 60*60*24*30;

        

        // To Calculate the time difference in Days...

        $days = 60*60*24;

        

        // To Calculate the time difference in Hours...

        $hours = 60*60;

        

        // To Calculate the time difference in Minutes...

        $minutes = 60;

        if(intval($time_differnce/$years) > 1)

        {

            return intval($time_differnce/$years)." years ago";

        }else if(intval($time_differnce/$years) > 0)

        {

            return intval($time_differnce/$years)." year ago";

        }else if(intval($time_differnce/$months) > 1)

        {

            return intval($time_differnce/$months)." months ago";

        }else if(intval(($time_differnce/$months)) > 0)

        {

            return intval(($time_differnce/$months))." month ago";

        }else if(intval(($time_differnce/$days)) > 1)

        {

            return intval(($time_differnce/$days))." days ago";

        }else if (intval(($time_differnce/$days)) > 0) 

        {

            return intval(($time_differnce/$days))." day ago";

        }else if (intval(($time_differnce/$hours)) > 1) 

        {

            return intval(($time_differnce/$hours))." hours ago";

        }else if (intval(($time_differnce/$hours)) > 0) 

        {

            return intval(($time_differnce/$hours))." hour ago";

        }else if (intval(($time_differnce/$minutes)) > 1) 

        {

            return intval(($time_differnce/$minutes))." minutes ago";

        }else if (intval(($time_differnce/$minutes)) > 0) 

        {

            return intval(($time_differnce/$minutes))." minute ago";

        }else if (intval(($time_differnce)) > 1) 

        {

            return intval(($time_differnce))." seconds ago";

        }else

        {

            return "few seconds ago";

        }

    }