TabularDisplay(3) User Contributed Perl Documentation TabularDisplay(3)NAMEText::TabularDisplay - Display text in formatted table output
SYNOPSIS
use Text::TabularDisplay;
my $table = Text::TabularDisplay->new(@columns);
$table->add(@row)
while (@row = $sth->fetchrow);
print $table->render;
+----+--------------+
| id | name |
+----+--------------+
| 1 | Tom |
| 2 | Dick |
| 3 | Barry |
| | (aka Bazza) |
| 4 | Harry |
+----+--------------+
DESCRIPTIONText::TabularDisplay simplifies displaying textual data in a table.
The output is identical to the columnar display of query results in the
mysql text monitor. For example, this data:
1, "Tom Jones", "(666) 555-1212"
2, "Barnaby Jones", "(666) 555-1213"
3, "Bridget Jones", "(666) 555-1214"
Used like so:
my $t = Text::TabularDisplay->new(qw(id name phone));
$t->add(1, "Tom Jones", "(666) 555-1212");
$t->add(2, "Barnaby Jones", "(666) 555-1213");
$t->add(3, "Bridget Jones", "(666) 555-1214");
print $t->render;
Produces:
+----+---------------+----------------+
| id | name | phone |
+----+---------------+----------------+
| 1 | Tom Jones | (666) 555-1212 |
| 2 | Barnaby Jones | (666) 555-1213 |
| 3 | Bridget Jones | (666) 555-1214 |
+----+---------------+----------------+
METHODSText::TabularDisplay has four primary methods: new(), columns(), add(),
and render(). new() creates a new Text::TabularDisplay instance;
columns() sets the column headers in the output table; add() adds data
to the instance; and render() returns a formatted string representation
of the instance.
There are also a few auxilliary convenience methods: clone(), items(),
reset(), populate(), and paginate().
new A Text::TabularDisplay instance can be created with column names
passed as constructor args, so these two calls produce similar
objects:
my $t1 = Text::TabularDisplay->new;
$t1->columns(qw< one two >);
my $t2 = Text::TabularDisplay->new(qw< one two >);
Calling new() on a Text::TabularDisplay instance returns a clone of
the object. See "clone" in Text::TabularDisplay.
columns
Gets or sets the column names for an instance. This method is
called automatically by the constructor with any parameters that
are passed to the constructor (if any are passed).
When called in scalar context, columns() returns the number of
columns in the instance, rather than the columns themselves. In
list context, copies of the columns names are returned; the names
of the columns cannot be modified this way.
add Takes a list of items and appends it to the list of items to be
displayed. add() can also take a reference to an array, so that
large arrays don't need to be copied.
As elements are processed, add() maintains the width of each column
so that the resulting table has the correct dimensions.
add() returns $self, so that calls to add() can be chained:
$t->add(@one)->add(@two)->add(@three);
render
render() does most of the actual work. It returns a string
containing the data added via add(), formatted as a table, with a
header containing the column names.
render() does not change the state of the object; it can be called
multiple times, with identical output (including identical running
time: the output of render is not cached).
If there are no columns defined, then the output table does not
contains a row of column names. Compare these two sequences:
my $t = Text::TabularDisplay->new;
$t->add(qw< 1 2 3 4 >);
$t->add(qw< 5 6 7 8 >);
print $t->render;
$t->columns(qw< one two three four >);
print $t->render;
# Example 1 output
+---+---+---+---+
| 1 | 2 | 3 | 4 |
| 5 | 6 | 7 | 8 |
+---+---+---+---+
# Example 2 output
+-----+-----+-------+------+
| one | two | three | four |
+-----+-----+-------+------+
| 1 | 2 | 3 | 4 |
| 5 | 6 | 7 | 8 |
+-----+-----+-------+------+
render() takes optional $start and $end arguments; these indicate
the start and end indexes for the data to be rendered. This can be
used for paging and the like:
$t->add(1, 2, 3)->add(4, 5, 6)->add(7, 8, 9)->add(10, 11, 12);
print $t->render(0, 1), "\n";
print $t->render(2, 3), "\n";
Produces:
+-------+--------+-------+
| First | Second | Third |
+-------+--------+-------+
| 1 | 2 | 3 |
| 4 | 5 | 6 |
+-------+--------+-------+
+-------+--------+-------+
| First | Second | Third |
+-------+--------+-------+
| 7 | 8 | 9 |
| 10 | 11 | 12 |
+-------+--------+-------+
As an aside, note the chaining of calls to add().
The elements in the table are padded such that there is the same
number of items in each row, including the header. Thus:
$t->columns(qw< One Two >);
print $t->render;
+-----+-----+----+
| One | Two | |
+-----+-----+----+
| 1 | 2 | 3 |
| 4 | 5 | 6 |
| 7 | 8 | 9 |
| 10 | 11 | 12 |
+-----+-----+----+
And:
$t->columns(qw< One Two Three Four>);
print $t->render;
+-----+-----+-------+------+
| One | Two | Three | Four |
+-----+-----+-------+------+
| 1 | 2 | 3 | |
| 4 | 5 | 6 | |
| 7 | 8 | 9 | |
| 10 | 11 | 12 | |
+-----+-----+-------+------+
OTHER METHODSclone()
The clone() method returns an identical copy of a
Text::TabularDisplay instance, completely separate from the cloned
instance.
items()
The items() method returns the number of elements currently stored
in the data structure:
printf "There are %d elements in \$t.\n", $t->items;
reset()
Reset deletes the data from the instance, including columns. If
passed arguments, it passes them to columns(), just like new().
populate()populate() as a special case of add(); populate() expects a
reference to an array of references to arrays, such as returned by
DBI's selectall_arrayref method:
$sql = "SELECT " . join(", ", @c) . " FROM mytable";
$t->columns(@c);
$t->populate($dbh->selectall_arrayref($sql));
This is for convenience only; the implementation maps this to
multiple calls to add().
NOTES / ISSUES
Text::TabularDisplay assumes it is handling strings, and does stringy
things with the data, like legnth() and sprintf(). Non-character data
can be passed in, of course, but will be treated as strings; this may
have ramifications for objects that implement overloading.
The biggest issue, though, is that this module duplicates a some of the
functionality of Data::ShowTable. Of course, Data::ShowTable is a
large, complex monolithic tool that does a lot of things, while
Text::TabularDisplay is small and fast.
AUTHOR
darren chamberlain <darren@cpan.org>
CREDITS
The following people have contributed patches, suggestions, tests,
feedback, or good karma:
David N. Blank-Edelman
Eric Cholet
Ken Youens-Clark
Michael Fowler
Paul Cameron
Prakash Kailasa
Slaven Rezic
VERSION
This documentation describes "Text::TabularDisplay" version 1.20.
perl v5.14.2 2011-08-16 TabularDisplay(3)
