Doc/mac/libaepack.tex

   1 \section{\module{aepack} ---
   2          Conversion between Python variables and AppleEvent data containers}
   3
   4 \declaremodule{standard}{aepack}
   5   \platform{Mac}
   6 %\moduleauthor{Jack Jansen?}{email}
   7 \modulesynopsis{Conversion between Python variables and AppleEvent
   8                 data containers.}
   9 \sectionauthor{Vincent Marchetti}{vincem@en.com}
  10
  11
  12 The \module{aepack} module defines functions for converting (packing)
  13 Python variables to AppleEvent descriptors and back (unpacking).
  14 Within Python the AppleEvent descriptor is handled by Python objects
  15 of built-in type \pytype{AEDesc}, defined in module \refmodule{AE}.
  16
  17 The \module{aepack} module defines the following functions:
  18
  19
  20 \begin{funcdesc}{pack}{x\optional{, forcetype}}
  21 Returns an \class{AEDesc} object  containing a conversion of Python
  22 value x. If \var{forcetype} is provided it specifies the descriptor
  23 type of the result. Otherwise, a default mapping of Python types to
  24 Apple Event descriptor types is used, as follows:
  25
  26 \begin{tableii}{l|l}{textrm}{Python type}{descriptor type}
  27   \lineii{\class{FSSpec}}{typeFSS}
  28   \lineii{\class{Alias}}{typeAlias}
  29   \lineii{integer}{typeLong (32 bit integer)}
  30   \lineii{float}{typeFloat (64 bit floating point)}
  31   \lineii{string}{typeText}
  32   \lineii{list}{typeAEList}
  33   \lineii{dictionary}{typeAERecord}
  34   \lineii{instance}{\emph{see below}}
  35 \end{tableii}
  36
  37 \pytype{FSSpec} and \pytype{Alias} are built-in object types defined
  38 in the module \refmodule{macfs}.
  39
  40 If \var{x} is a Python instance then this function attempts to call an
  41 \method{__aepack__()} method.  This method should return an
  42 \pytype{AE.AEDesc} object.
  43
  44 If the conversion \var{x} is not defined above, this function returns
  45 the Python string representation of a value (the repr() function)
  46 encoded as a text descriptor.
  47 \end{funcdesc}
  48
  49 \begin{funcdesc}{unpack}{x}
  50   \var{x} must be an object of type \class{AEDesc}. This function
  51   returns a Python object representation of the data in the Apple
  52   Event descriptor \var{x}. Simple AppleEvent data types (integer,
  53   text, float) are returned as their obvious Python counterparts.
  54   Apple Event lists are returned as Python lists, and the list
  55   elements are recursively unpacked.  Object references
  56   (ex. \code{line 3 of document 1}) are returned as instances of
  57   \class{aetypes.ObjectSpecifier}.  AppleEvent descriptors with
  58   descriptor type typeFSS are returned as \class{FSSpec}
  59   objects.  AppleEvent record descriptors are returned as Python
  60   dictionaries, with keys of type \class{?} and elements recursively
  61   unpacked.
  62 \end{funcdesc}
  63
  64
  65 \begin{seealso}
  66   \seemodule{AE}{Built-in access to Apple Event Manager routines.}
  67   \seemodule{aetypes}{Python definitions of codes for Apple Event
  68                       descriptor types.}
  69   \seetitle[http://developer.apple.com/techpubs/mac/IAC/IAC-2.html]{
  70             Inside Macintosh: Interapplication
  71             Communication}{Information about inter-process
  72             communications on the Macintosh.}
  73 \end{seealso}