title: How to link and unlink frameworks depending on Deployment in iOS
body: <p>i want to know how to link frameworks and unlink automatically depending on deployment target.</p>
  
  <p>For example Digits and Twitter Core frameworks are for minimum deployment target iOS 8.0 so i want to link these frameworks when app is running on iOS 8 and higher and when running on iOS 7 i do not want to link.</p>
  
  <p>i also checked setting the Framework options in Build Phases to Optional but its did not work.</p>
  
  <p>How i can specify these frameworks in Bridging Header file so that depending on Deployment that will be linked and unlinked automatically.</p>