Dorian Taylor
and 1 contributors

NAME

Data::Grid - Incremental read access to grid-based data

VERSION

Version 0.06

SYNOPSIS

    use Data::Grid;

    # Have the parser guess the kind of file, using defaults.

    my $grid = Data::Grid->parse('arbitrary.xls');

    # or

    my $grid = Data::Grid->parse(
        source  => 'arbitrary.csv', # or xls, or xlsx, or filehandle...
        header  => 1,               # first line is a header everywhere
        columns => [qw(a b c)],     # override the header
        options => \%options,       # driver-specific options
    );

    # Each object contains one or more tables.

    for my $table ($grid->tables) {

        # Each table has one or more rows.

        while (my $row = $table->next) {

            # The columns can be dereferenced as an array,

            my @cols = @$row; # or just $row->columns

            # or, if header is present or fields were named in the
            # constructor, as a hash.

            my %cols = %$row;

            # Now we can do stuff.
        }
    }

DESCRIPTION

Problem 1

You have a mountain of data files from two decades of using MS Office (and other) products, and you want to collate their contents into someplace sane.

Problem 2

The files are in numerous different formats, and a consistent interface would really cut down on the effort of extracting them.

Problem 3

You've looked at Data::Table and Spreadsheet::Read, but deemed their table-at-a-time strategy to be inappropriate for your purposes.

The goal of Data::Grid is to provide an extensible, uniform, object-oriented interface to all kinds of grid-shaped data. A key behaviour I'm after is to perform an incremental read over a potentially large data source, so as not to unnecessarily gobble up system resources.

DEVELOPER RELEASE

Odds are I will probably decide to change the interface at some point before locking in, and I don't want to guarantee consistency yet. If I do, and you use this, your code will probably break.

Suffice to say this module is ALPHA QUALITY at best.

METHODS

parse $FILE | %PARAMS

The principal way to instantiate a Data::Grid object is through the parse factory method. You can either pass it a filelike thing or a set of parameters. Filelike thing is either a filename, GLOB reference, SCALAR reference or ARRAY reference of scalars. If the filelike thing is passed alone, its type will be detected using File::MMagic. To tune this behaviour, use the parameters:

source

This is equivalent to $file.

If you know that the document you're opening has a header, set this flag to a true value and it will be consumed for use in "as_hash" in Data::Grid::Row. If there is more than one table in the document, set this value to an ARRAY reference of flags. This object will be treated as a ring, meaning that, for instance, if the header designation is [1, 0], the third table in the document will be treated as having a header, fourth will not, the fifth will, and so on.

columns

Specify a list of columns in lieu of a header, or otherwise override any header, which is thrown away. A single ARRAY reference of strings will be duplicated to each table in the document. An array of arrays will be applied to each table with the same wrapping behaviour as header.

start

Set a row offset, i.e, a number of rows to skip before any header. Since this is an offset, it starts with zero. Same rule applies for multiple tables in the document.

skip

Set a number of rows to skip after the header, defaulting, of course, to zero. Same multi-table rule applies.

options

This HASH reference will be passed as-is to the driver.

driver

Specify a driver and bypass type detection. Modules under the Data::Grid namespace can be handed in as CSV, Excel, and Excel::XLSX. Prefix with a + for other package namespaces.

checker

Specify either MMagic or MimeInfo to detect the type of file. MMagic is the default. In lieu of the class name

tables

Generate and return the array of tables.

fh

Retrieve the document's file handle embedded in the grid object.

EXTENSION INTERFACE

Take a look at Data::Grid::CSV or Data::Grid::Excel for clues on how to extend this package.

table_class

Returns the class to use for instantiating tables. Defaults to Data::Grid::Table, which is an abstract class. Override this accessor and its neighbours with your own values for extensions.

row_class

Returns the class to use for instantiating rows. Defaults to Data::Grid::Row.

cell_class

Returns the class to use for instantiating cells. Defaults to Data::Grid::Cell, again an abstract class.

table_params $POSITION

Generate a set of parameters suitable for passing in as a constructor, either as a hash or HASH reference, depending on calling context.

AUTHOR

Dorian Taylor, <dorian at cpan.org>

BUGS

Please report bugs to GitHub issues.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc Data::Grid

Alternatively, you can read the documentation on MetaCPAN.

SEE ALSO

COPYRIGHT & LICENSE

Copyright 2010-2018 Dorian Taylor.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.