What are the disadvantages of AJAX on Rails?

what are the scenario's where开发者_StackOverflow社区 Ajax could not be used in Rails Application. Is there any disadvantages of AJAX (AJAX on RAILS) if yes please mention which are they?

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• The browser may not be able to interpret javascript, but rails can detect that and you can act accordingly
• The user cannot back/forward or bookmark a particular state within the page, because it is dynamically generated
• Search engines cannot index particular states within the page

There may be others that i can't think of right now.

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I think the biggest disadvantage of AJAX in general is the desire to use is when it is not needed.