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AJAX Is it a cleanser or a bleach

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					         AJAX
Is it a cleanser or a bleach?

    Haritha Reddy Sama
          CIS 764

         Instructor
      Dr.Bill Hankley


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Overview
 Introduction   to AJAX

 Advantages


 Popular   Applications

 Disadvantages-    the other side of the
 coin
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Introduction to AJAX
   What is AJAX – a technique to process user
    request immediately

   Why AJAX – more time for sever to
    process the request




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How does it work


                              Delayed response
                              due to processing
                              by server




         Immediate
         response



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Advantages
 Interface is more responsive
 Waiting time is reduced
 Page encounters an error- applications
  fails graciously
 Traffic to and from server is reduced –
  bandwidth usage is most likely to
  decrease



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Some Popular AJAX Apps
   Google maps:
    (richer desktop interaction methods like Zoom
      in/Zoom out are possible)

    Google suggest:
    (Auto-completion)

    Google calendar:
    (Improved performance and smoother responses)

    Flickr photo sharing:
    (Multiple Interactions due to asynchronous
      communication)
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Other AJAX Apps
    A simple chat client

    Terminal
        Web Shell


    Programming
        HTML Form Assembler Live Form
        JotForm: WYSIWYG Form Builder




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CIS764   8
CIS764   9
The other side of the coin




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SEO Rhetoric - Don’t use AJAX

    When pages with Ajax are indexed, the data
     displayed by Ajax calls is not present in the
     page
         workarounds are required to get dynamic Ajax
          content indexed
         it’s simply not there in the page
    Content rendered via AJAX is done via
     javascript
         Search engine spiders cannot invoke javascript
          events to retrieve AJAX content

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Disadvantages
   Increased development time and costs

   Available frameworks and components still
    need to completely mature

   Not all concerns regarding security and
    user privacy have been answered

   Conflicts in modern browsers - navigate
    and create bookmarks
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Disadvantages (contd..)
   Not meant to be used in every application

   Concern of accessibility

   XMLHttpRequest object itself




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Workarounds - Go on an AJAX diet

   Use hidden divs rather than Ajax
       Search engines will index the content

   Need AJAX content to be indexed
       Provide hidden links that can be spidered

   Limit the complexity of the logic
       Javascript-free Ajax

   AJAX should be limited to providing a better user
    experience through RIAs ( Rich Internet
    Applications)

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Conclusions
   Keeping the advantages and
    disadvantages in mind one has to choose
    whether or not to have AJAX to retrieve
    the content/data in their application.




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References
    AJAX Patterns – Web site which has plethora of
     ajax examples
         http://ajaxpatterns.org/
    Presentation by Paul Buremmer from RED
     DOOR on AJAX
         http://www.semphonic.com/conf/AJAX_Paul_Bruem
          mer.pdf
    An article - Is AJAX right for my project?
         http://www.interaktonline.com/Support/Articles/Deta
          ils/AJAX%3A+Asynchronously+Moving+Forward-
          Is+AJAX+right+for+my+project%3F.html?id_art=36
          &id_asc=310

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Questions?




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