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Palm-1.400
River stage one • 3 direct dependents • 3 total dependents
/ Palm::StdAppInfo

NAME

Palm::StdAppInfo - Handle standard AppInfo blocks in Palm OS PDBs

VERSION

This document describes version 1.400 of Palm::StdAppInfo, released March 14, 2015 as part of Palm version 1.400.

SYNOPSIS

Usually:

    package MyPDBHandler;
    use Palm::StdAppInfo();		# Note the parentheses

    @ISA = qw( Palm::StdAppInfo );

    use constant APPINFO_PADDING = 1;

    sub ParseAppInfoBlock {
	my $self = shift;
	my $data = shift;
	my $appinfo = {};

	&Palm::StdAppInfo::parse_StdAppInfo($appinfo, $data);

	$app_specific_data = $appinfo->{other};
    }

    sub PackAppInfoBlock {
	my $self = shift;
	my $retval;

	$self->{appinfo}{other} = <pack application-specific data>;
	$retval = &Palm::StdAppInfo::pack_StdAppInfo($self->{appinfo});
	return $retval;
    }

Or as a standalone PDB helper class:

use Palm::StdAppInfo;

DESCRIPTION

Many Palm applications use a common format for keeping track of categories. The Palm::StdAppInfo class deals with this common format:

$pdb = new Palm::PDB;
$pdb->Load("myfile.pdb");

@categories  = @{ $pdb->{appinfo}{categories} };
$lastUniqueID =   $pdb->{appinfo}{lastUniqueID};
$other        =   $pdb->{appinfo}{other};

where:

@categories is an array of references-to-hash:

$cat = $categories[0];
$cat->{name}

The name of the category, a string of at most 16 characters.

$cat->{id}

The category ID, an integer in the range 0-255. Each category has a unique ID. By convention, 0 is reserved for the "Unfiled" category; IDs assigned by the Palm are in the range 1-127, and IDs assigned by the desktop are in the range 128-255.

$cat->{renamed}

A boolean. This field is true iff the category has been renamed since the last sync.

$lastUniqueID is (I think) the last category ID that was assigned.

$other is any data that follows the category list in the AppInfo block. If you're writing a helper class for a PDB that includes a category list, you should parse this field to get any data that follows the category list; you should also make sure that this field is initialized before you call &Palm::StdAppInfo::pack_AppInfo.

APPINFO_PADDING

Normally, the AppInfo block includes a byte of padding at the end, to bring its length to an even number. However, some databases use this byte for data.

If your database uses the padding byte for data, then your &ParseAppInfoBlock method (see "SYNOPSIS") should call &parse_StdAppInfo with a true $nopadding argument.

If, for whatever reason, you wish to inherit &StdAppInfo::ParseAppInfoBlock, then add

use constant APPINFO_PADDING => 0;

to your handler package, to tell it that the padding byte is really data.

FUNCTIONS

seed_StdAppInfo

&Palm::StdAppInfo::seed_StdAppInfo(\%appinfo);

Creates the standard fields in an existing AppInfo hash. Usually used to ensure that a newly-created AppInfo block contains an initialized category array:

my $appinfo = {};

&Palm::StdAppInfo::seed_StdAppInfo($appinfo);

Note: this is not a method.

newStdAppInfo

$appinfo = Palm::StdAppInfo->newStdAppInfo;

Like seed_StdAppInfo, but creates an AppInfo hash and returns a reference to it.

new

$pdb = new Palm::StdAppInfo;

Create a new PDB, initialized with nothing but a standard AppInfo block.

There are very few reasons to use this, and even fewer good ones. If you're writing a helper class to parse some PDB format that contains a category list, then you should make that helper class a subclass of Palm::StdAppInfo.

parse_StdAppInfo

$len = &Palm::StdAppInfo::parse_StdAppInfo(\%appinfo, $data, $nopadding);

This function (this is not a method) is intended to be called from within a PDB helper class's ParseAppInfoBlock method.

parse_StdAppInfo() parses a standard AppInfo block from the raw data $data and fills in the fields in %appinfo. It returns the number of bytes parsed.

$nopadding is optional, and defaults to false. Normally, the AppInfo block includes a padding byte at the end. If $nopadding is true, then &parse_StdAppInfo assumes that the padding byte is application data, and includes it in $appinfo{'other'}, so that the caller can parse it.

ParseAppInfoBlock

$pdb = new Palm::StdAppInfo;
$pdb->ParseAppInfoBlock($data);

If your application's AppInfo block contains standard category support and nothing else, you may choose to just inherit this method instead of writing your own ParseAppInfoBlock method. Otherwise, see the example in "SYNOPSIS".

pack_StdAppInfo

$data = &Palm::StdAppInfo::pack_StdAppInfo(\%appinfo);

This function (this is not a method) is intended to be called from within a PDB helper class's PackAppInfoBlock method.

pack_StdAppInfo takes an AppInfo hash and packs it as a string of raw data that can be written to a PDB.

Note that if you're using this inside a helper class's PackAppInfoBlock method, you should make sure that $appinfo{other} is properly initialized before you call &Palm::StdAppInfo::pack_StdAppInfo.

$nopadding is optional, and defaults to false. Normally, the AppInfo block includes a byte of padding at the end. If $nopadding is true, then &pack_StdAppInfo doesn't include this byte of padding, so that the application can use it.

PackAppInfoBlock

$pdb = new Palm::StdAppInfo;
$data = $pdb->PackAppInfoBlock();

If your application's AppInfo block contains standard category support and nothing else, you may choose to just inherit this method instead of writing your own PackAppInfoBlock method. Otherwise, see the example in "SYNOPSIS".

addCategory

$pdb->addCategory($name [, $id [, $renamed]]);

Adds a category to $pdb.

The $name argument specifies the new category's name.

The optional $id argument specifies the new category's numeric ID; if omitted or undefined, &addCategory will pick one.

The optional $renamed argument is a boolean value indicating whether the new category should be marked as having been modified. This defaults to true since, conceptually, &addCategory doesn't really add a category: it finds one whose name happens to be empty, and renames it.

Returns a true value if successful, false otherwise. In case of failure, &addCategory sets $Palm::StdAppInfo::error to an error message.

deleteCategory

$pdb->deleteCategory($name);

Deletes the category with name $name. Actually, though, it doesn't delete the category: it just changes its name to the empty string, and marks the category as renamed.

renameCategory

$pdb->renameCategory($oldname, $newname);

Renames the category named $oldname to $newname.

If successful, returns a true value. If there is no category named $oldname, returns a false value and sets $Palm::StdAppInfo::error to an error message.

SEE ALSO

Palm::PDB

CONFIGURATION AND ENVIRONMENT

Palm::StdAppInfo requires no configuration files or environment variables.

INCOMPATIBILITIES

None reported.

BUGS AND LIMITATIONS

No bugs have been reported.

AUTHORS

Andrew Arensburger <arensb AT ooblick.com>

Currently maintained by Christopher J. Madsen <perl AT cjmweb.net>

Please report any bugs or feature requests to <bug-Palm AT rt.cpan.org> or through the web interface at http://rt.cpan.org/Public/Bug/Report.html?Queue=Palm.

You can follow or contribute to p5-Palm's development at https://github.com/madsen/p5-Palm.

COPYRIGHT AND LICENSE

This software is copyright (c) 2003 by Andrew Arensburger & Alessandro Zummo.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENSE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.