An interface that describes an object representing an available update to
 the current application - this update may have several available patches
 from which one must be selected to download and install, for example we
 might select a binary difference patch first and attempt to apply that,
 then if the application process fails fall back to downloading a complete
 file-replace patch. This object also contains information about the update
 that the front end and other application services can use to learn more
 about what is going on.
[scriptable, uuid(9d6a388b-2e0c-4d0e-9a60-5c9739a7ada5)]
interface nsIUpdate : nsISupports

Attributes

 The Build ID of this update. Used to determine a particular build, down
 to the hour, minute and second of its creation. This allows the system
 to differentiate between several nightly builds with the same |version|
 for example.
attribute AString buildID 
 The channel used to retrieve this update from the Update Service.
attribute AString channel 
 The URL to a page which offers details about the content of this
 update. Ideally, this page is not the release notes but some other page
 that summarizes the differences between this update and the previous,
 which also links to the release notes.
attribute AString detailsURL 
 A numeric error code that conveys additional information about the state
 of a failed update.  If the update is not in the "failed" state, then this
 value is zero.

 TODO: Define typical error codes (for now, see updater/errors.h)
attribute long errorCode 
 The Addon version of this update. Used by the Extension System to track
 compatibility of installed addons with this update.
attribute AString extensionVersion 
 When the update was installed.
attribute long long installDate 
 Whether or not the update being downloaded is a complete replacement of
 the user's existing installation or a patch representing the difference
 between the new version and the previous version.
attribute boolean isCompleteUpdate 
 Whether or not the update is a security update or not. If this is true,
 then we present more serious sounding user interface messages to the
 user.
attribute boolean isSecurityUpdate 
 The URL to a HTML fragment that contains a license for this update. If
 this is specified, the user is shown the license file after they choose
 to install the update and they must agree to it before the download
 commences.
attribute AString licenseURL 
 The name of the update, or "<Application Name> <Update Version>"
attribute AString name 
 The number of patches supplied by this update.
readonly attribute unsigned long patchCount 
 The Toolkit version of this update.
attribute AString platformVersion 
 The currently selected patch for this update.
readonly attribute nsIUpdatePatch selectedPatch 
 The URL to the Update Service that supplied this update.
attribute AString serviceURL 
 The state of the selected patch:
   "downloading"       The update is being downloaded.
   "pending"           The update is ready to be applied.
   "applying"          The update is being applied.
   "succeeded"         The update was successfully applied.
   "download-failed"   The update failed to be downloaded.
   "failed"            The update failed to be applied.
attribute AString state 
 A message associated with this update, if any.
attribute AString statusText 
 The type of update:
   "major"  A major new version of the Application
   "minor"  A minor update to the Application (e.g. security update)
attribute AString type 
 The Application version of this update.
attribute AString version

Methods

 Retrieves a patch.
 @param   index
          The index of the patch to retrieve.
 @returns The nsIUpdatePatch at the specified index.
nsIUpdatePatch getPatchAt(in unsigned long index) 
 Serializes this update object into a DOM Element
 @param   updates
          The document to serialize into
 @returns The DOM Element created by the serialization process
nsIDOMElement serialize(in nsIDOMDocument updates)