Saturday, October 26, 2013

Twitter: How To Implement Summary Card


Hello Friends, this tutorial will help you to implement one of the Twitter card, Summary Card.


There are different cards available in Twitter. like

  • Summary
  • Photo
  • Product
  • Gallery
  • App
  • Player


Today we will see implementation of Summary Card.

Summary card gives preview of website to reader which get shared via twitter.
It is a rich snippet which display Title, Description and Image of shared website. 




To use summary card you need to add few meta tags in your webpage.

Follow the given step to get these meta tags

2.   Choose Twitter Card, which is Summary.


3.   Add meta information 

twitter:site (Site Twitter Username)
twitter:title (Site/Webpage Title)
twitter:description (Site/Webpage Description)
twitter:creator (Site Twitter Creator)
twitter:image:src (Site/Webpage Image)
twitter:domain (Site Domain) 



4.   Then select sample embed code and put it into head section of your site/webpage.

       

5.    After updating meta tags into your website visit validation section of Twitter Card and click on “Validate & Apply” button.



6.     It will ask for website URL , then past your website URL where you have recently updated summary card.



7.    Put that URL and click “Go!”

8.    If all goes well then it will show Summary card preview of right side.



9.    If something goes wrong then it will gives you warning.



Hope this tutorial will help to get start with Twitter’s Summary card.
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Thursday, October 24, 2013

jQuery: How To Make Your Image based Website Load Faster

Hello Friends, Today I am writing my second tutorial post regarding optimization of webpage which contains bulks of images.

Let’s consider one scenario where you want to display hundreds of images at a time. And also your client wants this webpage should load faster.




Now here is the problem, webpage won’t get loaded fully unless all of its images get download first. Which means as number of images in webpage increases the load time of that webpage also increased.

To solve this problem we must reduce the webpage load time, indirectly it means that we need to load less amount of images.

Consider a scenario where we load only one default image at each place of actual images indicating that these actual images are getting downloaded and using Javascript we will download these actual images after window finishes its loading.

Following diagrams will help you to understand the flow.



as one image wont takes too much time to load, therefore webpage speed increase and it also help to improve user experience as it tells user that all images are in the process of download.

Now we will see some code to implement this flow.
First create html page to store images.

 <body>
    <div>
 <img data-image="[actual-image-path]" src="default-loading-image-path" class="item"/>
  <img data-image="[actual-image-path]" src="default-loading-image-path"/ class="item">
  <img data-image="[actual-image-path]" src="default-loading-image-path"/ class="item">
  <img data-image="[actual-image-path]" src="default-loading-image-path"/ class="item">
</div>
  </body>

here we have created four images,where we set default loading image in source property and actual image in image data property of image tag.

Now we will add jQuery script in head section to load all actual images after page get loaded.

 <script  type="text/javascript">
 $('document').ready(function(){
             //execute after window finishes loading
    $(window).load(function(){
                   //search each image by its class name
  $('.item').each(function(index){
                          //replace current image path with actual image path
 $(this).attr('src', $(this).data('image'));
  });
});
 });
</script>

script get executed after all component get downloaded and browser is ready to render them. at that time we load all images.


Hope it will help you.
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Wednesday, October 16, 2013

AJAX - How To Retrieve JSON Response from PHP script

Hello Friends, This is my first tutorial post.

Today I'll explain you how to retrieve JSON response via Ajax call.

First we build a PHP script to send response in JSON format, then we will gather this response from an Ajax call through jQuery script.

Let’s first create a PHP script 

Create a PHP script, I’ll name it as “json_response.php”
And add following code in it

json_response.php

<?php

//set header for JSON response
header("Content-Type: application/json");

//render array in JSON format
echo json_encode(array('status' => 200, 'message' => 'Response from PHP script in JSON format.'));

This is a basic example to send JSON response.
PHP script will send response with status code and message.

Now create a HTML file to fetch JSON response and add it in header tag.

Create a HTML file, I’ll name it as “json_response.html”
And add following code.

json_response.html

<html>                                                                                                            
    <head> 
                                                                                                                           <script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>                  
        <script type="text/javascript">                                                                                
            $('document').ready(function() {                                                                          
      //create ajax call to fetch json response                                                            
                $.ajax({                                                                                                                          url: 'json_header.php',                                                                                
                    type: 'GET',                                                                                               
                    dataType: 'JSON', // it is necessary to get JSON response                                                                                                         
                    success: function(response) {                                                                      
                       // if reponse status is success                                                                  
                        if (response.status == 200) {                                                            
       // add message to header tag                                                    
                            $('#message').html(response.message);                                    
                        }                                                                                             
                    }                                                                                                 
                });                                                                                                   
            });                                                                                                       
        </script>                                                                                                   
    </head>                                                                                                        
    <body>                                                                                                         
        <h1 id="message"></h1>                                                                             
    </body>                                                                                                         
</html>  
                                                                                                       
Note: It is very important to add ajax request parameter  dataType: 'JSON' to fetch response in JSON format.

After running HTML file in browser you see the header tag has message as

Response from PHP script in JSON format.


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