NAME

       Padre::DB::LastPositionInFile - Storage class for stateful cursor positions

SYNOPSIS

         Padre::DB::LastPositionInFile->set_last_pos($file, $pos);
         my $pos = Padre::DB::LastPositionInFile->get_last_pos($file);

DESCRIPTION

       This class allows storing in Padre's database the last cursor position in a file. This is
       useful in order to put the cursor back to where it was when re-opening this file later on.

       Please note that due to limitations in the way we generate the class, imposed by ORLite,
       automatic translation for Portable Perl is only applied if you use the "set_last_pos" and
       "get_last_pos" methods.

METHODS

   set_last_pos
         set_last_pos( $file, $pos )

       Record $pos as the last known cursor position in $file.

       Applies appropriate path translation if we are running in Portable Perl.

   get_last_pos
         get_last_pos( $file )

       Return the last known cursor position for $file. Return "undef" if no position was
       recorded for this file.

       Applies appropriate path translation if we are running in Portable Perl.

   base
         # Returns 'Padre::DB'
         my $namespace = Padre::DB::LastPositionInFile->base;

       Normally you will only need to work directly with a table class, and only with one ORLite
       package.

       However, if for some reason you need to work with multiple ORLite packages at the same
       time without hardcoding the root namespace all the time, you can determine the root
       namespace from an object or table class with the "base" method.

   table
         # Returns 'last_position_in_file'
         print Padre::DB::LastPositionInFile->table;

       While you should not need the name of table for any simple operations, from time to time
       you may need it programatically. If you do need it, you can use the "table" method to get
       the table name.

   load
         my $object = Padre::DB::LastPositionInFile->load( $name );

       If your table has single column primary key, a "load" method will be generated in the
       class. If there is no primary key, the method is not created.

       The "load" method provides a shortcut mechanism for fetching a single object based on the
       value of the primary key. However it should only be used for cases where your code trusts
       the record to already exists.

       It returns a "Padre::DB::LastPositionInFile" object, or throws an exception if the object
       does not exist.

   select
         # Get all objects in list context
         my @list = Padre::DB::LastPositionInFile->select;

         # Get a subset of objects in scalar context
         my $array_ref = Padre::DB::LastPositionInFile->select(
             'where name > ? order by name',
             1000,
         );

       The "select" method executes a typical SQL "SELECT" query on the last_position_in_file
       table.

       It takes an optional argument of a SQL phrase to be added after the "FROM
       last_position_in_file" section of the query, followed by variables to be bound to the
       placeholders in the SQL phrase. Any SQL that is compatible with SQLite can be used in the
       parameter.

       Returns a list of Padre::DB::LastPositionInFile objects when called in list context, or a
       reference to an "ARRAY" of Padre::DB::LastPositionInFile objects when called in scalar
       context.

       Throws an exception on error, typically directly from the DBI layer.

   iterate
         Padre::DB::LastPositionInFile->iterate( sub {
             print $_->name . "\n";
         } );

       The "iterate" method enables the processing of large tables one record at a time without
       loading having to them all into memory in advance.

       This plays well to the strength of SQLite, allowing it to do the work of loading
       arbitrarily large stream of records from disk while retaining the full power of Perl when
       processing the records.

       The last argument to "iterate" must be a subroutine reference that will be called for each
       element in the list, with the object provided in the topic variable $_.

       This makes the "iterate" code fragment above functionally equivalent to the following,
       except with an O(1) memory cost instead of O(n).

         foreach ( Padre::DB::LastPositionInFile->select ) {
             print $_->name . "\n";
         }

       You can filter the list via SQL in the same way you can with "select".

         Padre::DB::LastPositionInFile->iterate(
             'order by ?', 'name',
             sub {
                 print $_->name . "\n";
             }
         );

       You can also use it in raw form from the root namespace for better control.  Using this
       form also allows for the use of arbitrarily complex queries, including joins. Instead of
       being objects, rows are provided as "ARRAY" references when used in this form.

         Padre::DB->iterate(
             'select name from last_position_in_file order by name',
             sub {
                 print $_->[0] . "\n";
             }
         );

   count
         # How many objects are in the table
         my $rows = Padre::DB::LastPositionInFile->count;

         # How many objects
         my $small = Padre::DB::LastPositionInFile->count(
             'where name > ?',
             1000,
         );

       The "count" method executes a "SELECT COUNT(*)" query on the last_position_in_file table.

       It takes an optional argument of a SQL phrase to be added after the "FROM
       last_position_in_file" section of the query, followed by variables to be bound to the
       placeholders in the SQL phrase. Any SQL that is compatible with SQLite can be used in the
       parameter.

       Returns the number of objects that match the condition.

       Throws an exception on error, typically directly from the DBI layer.

   new
         TO BE COMPLETED

       The "new" constructor is used to create a new abstract object that is not (yet) written to
       the database.

       Returns a new Padre::DB::LastPositionInFile object.

   create
         my $object = Padre::DB::LastPositionInFile->create(

             name => 'value',

             position => 'value',

         );

       The "create" constructor is a one-step combination of "new" and "insert" that takes the
       column parameters, creates a new Padre::DB::LastPositionInFile object, inserts the
       appropriate row into the last_position_in_file table, and then returns the object.

       If the primary key column "name" is not provided to the constructor (or it is false) the
       object returned will have "name" set to the new unique identifier.

       Returns a new last_position_in_file object, or throws an exception on error, typically
       from the DBI layer.

   insert
         $object->insert;

       The "insert" method commits a new object (created with the "new" method) into the
       database.

       If a the primary key column "name" is not provided to the constructor (or it is false) the
       object returned will have "name" set to the new unique identifier.

       Returns the object itself as a convenience, or throws an exception on error, typically
       from the DBI layer.

   delete
         # Delete a single instantiated object
         $object->delete;

         # Delete multiple rows from the last_position_in_file table
         Padre::DB::LastPositionInFile->delete('where name > ?', 1000);

       The "delete" method can be used in a class form and an instance form.

       When used on an existing Padre::DB::LastPositionInFile instance, the "delete" method
       removes that specific instance from the "last_position_in_file", leaving the object intact
       for you to deal with post-delete actions as you wish.

       When used as a class method, it takes a compulsory argument of a SQL phrase to be added
       after the "DELETE FROM last_position_in_file" section of the query, followed by variables
       to be bound to the placeholders in the SQL phrase. Any SQL that is compatible with SQLite
       can be used in the parameter.

       Returns true on success or throws an exception on error, or if you attempt to call delete
       without a SQL condition phrase.

   truncate
         # Delete all records in the last_position_in_file table
         Padre::DB::LastPositionInFile->truncate;

       To prevent the common and extremely dangerous error case where deletion is called
       accidentally without providing a condition, the use of the "delete" method without a
       specific condition is forbidden.

       Instead, the distinct method "truncate" is provided to delete all records in a table with
       specific intent.

       Returns true, or throws an exception on error.

ACCESSORS

   name
         if ( $object->name ) {
             print "Object has been inserted\n";
         } else {
             print "Object has not been inserted\n";
         }

       Returns true, or throws an exception on error.

       REMAINING ACCESSORS TO BE COMPLETED

SQL

       The last_position_in_file table was originally created with the following SQL command.

         CREATE TABLE last_position_in_file (
             name varchar(255) not null primary key,
             position integer not null
         )

SUPPORT

       Padre::DB::LastPositionInFile is part of the Padre::DB API.

       See the documentation for Padre::DB for more information.

AUTHOR

       Adam Kennedy <adamk@cpan.org>

COPYRIGHT

       Copyright 2008-2013 The Padre development team as listed in Padre.pm.

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

       The full text of the license can be found in the LICENSE file included with this module.