FileIO Xtra
Version 1.0.4 - 09dec97 CH

FileIO Xtra for Macromedia Director 6.0
=======================================

FileIO provides a set of methods allowing users of Macromedia Director 6.0 to
programmatically access files using the Lingo scripting language. The FileIO
Xtra is a scripting Xtra.  The scripting Xtra interface is portable across
all Macromedia products.  Hence the FileIO Xtra may be used with Authorware 4.

Using FileIO
============

If automatic opening is desired, place a copy of the FileIO Xtra for your platform
into Application Xtra's folder. If automatic opening is not desired, the Xtra can be 
placed anywhere and opened using Lingo's 'openXLib' command. This applies to 
projector's as well, the Xtra must be placed in an Xtra's folder in the same folder 
as the projector.

Each instance of FileIO can reference a single open file. If multiple files are to
be opened simultaneously, a new instance of FileIO is required for each opened file.
A single instance can be used to open multiple files, as long as the file is closed
before a new file is opened. To create a new instance, use the new() method, defined
below. To dispose of an instance, set the instance variable to 0. All methods that
read from or write to the file must be called after the file has been opened using
the openFile() method. If a new file is to be opened using the same instance, the
file must be closed using closeFile(). Files can be opened in three different modes:
Read, Write and Read/Write. When writing to a file, the contents of the file after
the current position are overwritten.

Example Lingo

 set myFile = new(xtra "fileio")      -- Create an instance of FileIO
 set fileName = displayOpen(myFile)   -- Display Open Dialog and return the fileName
 openFile(myFile, fileName, 1)        -- Open the file
 set theFile = readFile(myFile)       -- Read the file and return a string to Lingo
 closeFile(myFile)                    -- Close the file
 set myFile = 0                       -- Dispose of the instance

In this example, we created a new instance and stored it in the variable myFile.
Next, the displayOpen() method is used to display an open dialog to allow a file to
be chosen. The file is returned as a fully-qualified path string to Lingo. The file
is then opened in read only mode, the contents of the file are read, and the file is
closed. Lastly, the instance is disposed of.

Known Problems
==============

The createFile() method does not support relative filenames, or the Lingo '@' 
operator in pathnames. This will be fixed in a later version.

The displaySave() method does not directly inform Lingo whether a user is 
replacing an existing file. The workaround is to attempt to create the file using
createFile() and check the error code for a "File Already Exists" error.

History
=======

09dec97 (v1.0.4)

Fixed a problem leading to garbage characters appearing at the ends of lines, 
or possibly crash. 

18apr97 (v1.0.2)

Fixed parenting problem with displaySave() and displayOpen() methods.
Added support for Authorware.

27may96 (v1.0.1)

Added support for double-byte character sets.
Added version() method to report FileIO Xtra version information. 
Added getOSDir() to return a full path to the Windows Directory/System Folder.

15mar96 (v1.0.0 Beta)

First public release.

Method Reference
================

The first line of each definition contains the method name, a list of parameters and
thier value types. The internal name of the FileIO Xtra is "fileio". This name is
used whenever referencing the xtra using the form 'xtra "fileio"'.

Note that while Director and projector's can use net-based files by supplying a URL
for a filename, the FileIO Xtra cannot. It is limited to accessesing files available
via filesystems mounted on the local system.

New methods will appear at the bottom of this list.

---

mMessageList( xtra reference )

Returns a list of methods and parameters, as well as a brief explanation of each.

---

new( xtra reference )

This is called to create a new instance of FileIO. The Xtra can be referenced by name
or number. It returns an instance variable used to reference the instance.

---

fileName( instance )

Returns the fileName string of the current open file.  The file must be open use this
method.

---

status( instance )

Returns the error code returned by the last method called. The value is returned as
an integer. 

---

error( instance, int error )

Returns a readable error string. A numeric error code is passed in as the
second argument. The errors returned can be any of the following:

"OK"
"Memory allocation failure"
"File directory full"
"Volume full"
"Volume not found"
"I/O Error"
"Bad file name"
"File not open"
"Too many files open"
"File not found"
"No such drive"
"No disk in drive"
"Directory not found"
"Instance has an open file"
"File already exists"
"File is opened read-only"
"File is opened write-only"
"Unknown error"

---

setFilterMask( instance, string mask )

Sets the filter mask used by calls to displayOpen() and displaySave(). The filter
mask determines what files to show when displaying an Open or Save dialog. The second
parameter is a string representing the filter mask to set. On Windows, this is a
comma seperated string of file types and associated extensions (e.g. "All
Files,*.*,Text Files,*.TXT"), and a string of types on the Macintosh (e.g.
"TEXTPICT"). On Windows, the filter mask string is limited to 256 characters. On the
Macintosh, you are limited to four four-character types.  When a new instance of
FileIO is created, the filter masks defaults to all files. To reset the filter mask to
display all files after it has been set, just pass in an empty string (e.g.
setFilterMask(me, "")).

---

openFile( instance, string fileName, int openMode )

Opens the named file. This call must be used before any read/write operations can
take place. The filename can be either a fully-qualified path and filename, or a
relative filename. The Lingo '@' pathname operator is supported. The openMode
parameter specifies whether to open the file in Read, Write or ReadWrite mode. Valid
Flags are: 0 Read/Write, 1 Read, 2 Write.

---

closeFile( instance )

Closes a file that has been previously opened using the openFile() method.

---

displayOpen( instance )

Displays a platform specific Open dialog allowing a user to specify a file. Returns a
fully-qualified path and fileName to Lingo. The setFilterMask() method can be used to
control what file types are displayed in the dialog.

---

displaySave( instance, string title, string defaultFileName )

Displays a platform specific Save dialog allowing a user to specify a file. Returns a
fully-qualified path and fileName to Lingo. The setFilterMask() method can be used to
control what file types are displayed in the dialog. The string and defaultFileName 
parameters allow you to specifiy a default filename to be displayed, as well as title
text for the save dialog. 

---

createFile( instance, string fileName )

Creates a file. The fileName must be either a fileName to be created in the current
directory, or a fully-qualified path and fileName. The Lingo '@' pathname operator
and relative paths are not supported. After creating the new file, the file must be
opened before it can be written to.

---

setPosition( instance, position )

Sets the file position of the current open file. The file must be open to use this 
method.

---

getPosition( instance )

Gets the file position of the current open file. Returned as an integer. The file
must be open to use this method. 

---

getLength( instance )

Gets the length of the currently opened file. Returned as an integer. The file must
be open use this method. The value returned is the length of the file in bytes. 

---

writeChar( instance, string theChar )

Writes a single character to the file at the current position. The file must be open
in write or read/write mode to use this method.

---

writeString( instance, string theString )

Writes a string to the file at the current position. The file must be open in write
or read/write mode to use this method.

---

readChar( instance )

Reads the character (either single or double-byte) at the current position and then 
increments the position. The character is returned to Lingo as a string. The file must 
be open in read or read/write mode to use this method. 

---

readLine( instance )

Reads from the current position up to and including the next CR, increments the
position, and returns the string to Lingo.  The file must be open in read or
read/write mode to use this method. 

---

readFile( instance )

Reads from the current position to the end of the file and returns the file to Lingo
as a string.  The file must be open in read or read/write mode to use this method.

---

readWord( instance )

Reads the next word starting at the current position.  The file must be open in read
or read/write mode to use this method. 

---

readToken( instance, string skipChar, string breakChar )

Reads the next 'token' starting at the current position. Characters matching the
skipChar parameter are "skipped" and the file is read until breakChar is encountered.
The file must be open in read or read/write mode to use this method. This method will
read double-byte tokens as long as the skip and break are single-byte characters. It
will not detect double-byte skip or break characters.

---

getFinderInfo( instance )

Returns the Type and Creator of the current file as a string. This method does
nothing when used under Windows.  The file must be open to use this method.
 
---
 
setFinderInfo( instance, string typeAndCreator )

Sets the Type and Creator of the current file. The string takes the form of a space
seperated set of TYPE and CREATOR codes (e.g. "TEXT TTXT"). This method does nothing
when used under Windows.  The file must be open to use this method.

---

delete( instance )

Deletes the currently opened file.  The file must be open use this method.

---

version( xtraRef )

Returns FileIO version and build information. Useful when filing 
bug reports, determining installed version while authoring, etc. No practical use beyond this.
 
---

getOSDir( )

Global method that returns the full path to either the Windows directory, or the System Folder 
depending on which OS is currently being used. Does not require a child instance or
Xtra reference to call.

---
