1TabularDisplay(3) User Contributed Perl Documentation TabularDisplay(3)
2
6 Text::TabularDisplay - Display text in formatted table output
7
9 use Text::TabularDisplay;
10 my $table = Text::TabularDisplay->new(@columns);
12 $table->add(@row)
13 while (@row = $sth->fetchrow);
14 print $table->render;
15 +----+--------------+
17 | id | name |
18 +----+--------------+
19 | 1 | Tom |
20 | 2 | Dick |
21 | 3 | Barry |
22 | | (aka Bazza) |
23 | 4 | Harry |
24 +----+--------------+
25
27 Text::TabularDisplay simplifies displaying textual data in a table.
28 The output is identical to the columnar display of query results in the
29 mysql text monitor. For example, this data:
30 1, "Tom Jones", "(666) 555-1212"
32 2, "Barnaby Jones", "(666) 555-1213"
33 3, "Bridget Jones", "(666) 555-1214"
34 Used like so:
36 my $t = Text::TabularDisplay->new(qw(id name phone));
38 $t->add(1, "Tom Jones", "(666) 555-1212");
39 $t->add(2, "Barnaby Jones", "(666) 555-1213");
40 $t->add(3, "Bridget Jones", "(666) 555-1214");
41 print $t->render;
42 Produces:
44 +----+---------------+----------------+
46 | id | name | phone |
47 +----+---------------+----------------+
48 | 1 | Tom Jones | (666) 555-1212 |
49 | 2 | Barnaby Jones | (666) 555-1213 |
50 | 3 | Bridget Jones | (666) 555-1214 |
51 +----+---------------+----------------+
52
54 Text::TabularDisplay has four primary methods: new(), columns(), add(),
55 and render(). new() creates a new Text::TabularDisplay instance;
56 columns() sets the column headers in the output table; add() adds data
57 to the instance; and render() returns a formatted string representation
58 of the instance.
59 There are also a few auxiliary convenience methods: clone(), items(),
61 reset(), populate(), and paginate().
62 new A Text::TabularDisplay instance can be created with column names
64 passed as constructor args, so these two calls produce similar
65 objects:
66 my $t1 = Text::TabularDisplay->new;
68 $t1->columns(qw< one two >);
69 my $t2 = Text::TabularDisplay->new(qw< one two >);
71 Calling new() on a Text::TabularDisplay instance returns a clone of
73 the object. See "clone" in Text::TabularDisplay.
74 columns
76 Gets or sets the column names for an instance. This method is
77 called automatically by the constructor with any parameters that
78 are passed to the constructor (if any are passed).
79 When called in scalar context, columns() returns the number of
81 columns in the instance, rather than the columns themselves. In
82 list context, copies of the columns names are returned; the names
83 of the columns cannot be modified this way.
84 add Takes a list of items and appends it to the list of items to be
86 displayed. add() can also take a reference to an array, so that
87 large arrays don't need to be copied.
88 As elements are processed, add() maintains the width of each column
90 so that the resulting table has the correct dimensions.
91 add() returns $self, so that calls to add() can be chained:
93 $t->add(@one)->add(@two)->add(@three);
95 render
97 render() does most of the actual work. It returns a string
98 containing the data added via add(), formatted as a table, with a
99 header containing the column names.
100 render() does not change the state of the object; it can be called
102 multiple times, with identical output (including identical running
103 time: the output of render is not cached).
104 If there are no columns defined, then the output table does not
106 contains a row of column names. Compare these two sequences:
107 my $t = Text::TabularDisplay->new;
109 $t->add(qw< 1 2 3 4 >);
110 $t->add(qw< 5 6 7 8 >);
111 print $t->render;
112 $t->columns(qw< one two three four >);
114 print $t->render;
115 # Example 1 output
117 +---+---+---+---+
118 | 1 | 2 | 3 | 4 |
119 | 5 | 6 | 7 | 8 |
120 +---+---+---+---+
121 # Example 2 output
123 +-----+-----+-------+------+
124 | one | two | three | four |
125 +-----+-----+-------+------+
126 | 1 | 2 | 3 | 4 |
127 | 5 | 6 | 7 | 8 |
128 +-----+-----+-------+------+
129 render() takes optional $start and $end arguments; these indicate
131 the start and end indexes for the data to be rendered. This can be
132 used for paging and the like:
133 $t->add(1, 2, 3)->add(4, 5, 6)->add(7, 8, 9)->add(10, 11, 12);
135 print $t->render(0, 1), "\n";
136 print $t->render(2, 3), "\n";
137 Produces:
139 +-------+--------+-------+
141 | First | Second | Third |
142 +-------+--------+-------+
143 | 1 | 2 | 3 |
144 | 4 | 5 | 6 |
145 +-------+--------+-------+
146 +-------+--------+-------+
148 | First | Second | Third |
149 +-------+--------+-------+
150 | 7 | 8 | 9 |
151 | 10 | 11 | 12 |
152 +-------+--------+-------+
153 As an aside, note the chaining of calls to add().
155 The elements in the table are padded such that there is the same
157 number of items in each row, including the header. Thus:
158 $t->columns(qw< One Two >);
160 print $t->render;
161 +-----+-----+----+
163 | One | Two | |
164 +-----+-----+----+
165 | 1 | 2 | 3 |
166 | 4 | 5 | 6 |
167 | 7 | 8 | 9 |
168 | 10 | 11 | 12 |
169 +-----+-----+----+
170 And:
172 $t->columns(qw< One Two Three Four>);
174 print $t->render;
175 +-----+-----+-------+------+
177 | One | Two | Three | Four |
178 +-----+-----+-------+------+
179 | 1 | 2 | 3 | |
180 | 4 | 5 | 6 | |
181 | 7 | 8 | 9 | |
182 | 10 | 11 | 12 | |
183 +-----+-----+-------+------+
184
186 clone()
187 The clone() method returns an identical copy of a
188 Text::TabularDisplay instance, completely separate from the cloned
189 instance.
190 items()
192 The items() method returns the number of elements currently stored
193 in the data structure:
194 printf "There are %d elements in \$t.\n", $t->items;
196 reset()
198 Reset deletes the data from the instance, including columns. If
199 passed arguments, it passes them to columns(), just like new().
200 populate()
202 populate() as a special case of add(); populate() expects a
203 reference to an array of references to arrays, such as returned by
204 DBI's selectall_arrayref method:
205 $sql = "SELECT " . join(", ", @c) . " FROM mytable";
207 $t->columns(@c);
208 $t->populate($dbh->selectall_arrayref($sql));
209 This is for convenience only; the implementation maps this to
211 multiple calls to add().
212
214 Text::TabularDisplay assumes it is handling strings, and does stringy
215 things with the data, like length() and sprintf(). Non-character data
216 can be passed in, of course, but will be treated as strings; this may
217 have ramifications for objects that implement overloading.
218 The biggest issue, though, is that this module duplicates a some of the
220 functionality of Data::ShowTable. Of course, Data::ShowTable is a
221 large, complex monolithic tool that does a lot of things, while
222 Text::TabularDisplay is small and fast.
223
225 darren chamberlain <darren@cpan.org>
226
228 The following people have contributed patches, suggestions, tests,
229 feedback, or good karma:
230 David N. Blank-Edelman
232 Eric Cholet
233 Ken Youens-Clark
234 Michael Fowler
235 Paul Cameron
236 Prakash Kailasa
237 Slaven Rezic
238 Harlan Lieberman-Berg
239 Patrick Kuijvenhoven
240 Miko O'Sullivan
241
243 This documentation describes "Text::TabularDisplay" version 1.38.
244perl v5.32.1 2021-01-27 TabularDisplay(3)