SLComposeServiceViewController class provides a standard compose view you can present for social sharing extensions on both platforms. By default, the compose view includes items such as an editable text view and an indication of remaining characters, in addition to support for previewing attachments and displaying configuration items, such as an account or privacy picker.
Presenting the Compose View
Posting or Canceling a Post
A Boolean value that indicates whether the current content and attachments are valid.
Performs validation of the current content and updates the state of the Post button, if appropriate.
Enabling Additional Configuration
Enabling Text Autocompletion
Accessing Content in the Compose View