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, "")
    }
}

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

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.

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');

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;
            }
        }
 }

jQuery Form Validation

Tired of validating the form using javascript. Here is the code to validate the form using jQuery.


  function submit_form()
{
var formElements = $('#form_name .required'); // Reading all elements in the form which are having class as required

var error = 0;

formElements.each(function() { // Looping all the elements which are having the class name as required...
if($(this).val() == "") {  // Checking the value of the field
                                                // Showing the border color as red if the field is empty
$(this).css('border','1px solid red');
error++;
} else {
                                                // removing the border if the field has the value....
$(this).css('border','none');
}
});
}

Use the submit_form function in onsubmit of the form.

The fields in the form which need to be validated should be given as below.

<input type="text" name="field_name" class="required" />

If we add the class required for the textbox, it validates otherwise it doesnot validate the textbox.

Gmail Type Chat using PHP & Jquery

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