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I need to set the http header. How to do this in Magento? Where i can set the http header? Is there any procedure in mangento to do this?
You need to be more clear on where you want this header ?
If you want this on every page, then you can write an observer and listen an event like predispatch and set your http headers over there..
Alternatively you can also try to implement this using htaccess.. Try inserting this to ur htaccess file ..
Header set Cache-Control "no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires "0"
To check, you can load any page of your site, and then check the headers using the network tab..