Provided by: libdata-report-perl_0.10-1_all 
NAME
Data::Report - Framework for flexible reporting
SYNOPSIS
use Data::Report;
# Create a new reporter.
my $rep = Data::Report::->create(type => "text"); # or "html", or "csv", ...
# Define the layout.
$rep->set_layout
([ { name => "acct", title => "Acct", width => 6 },
{ name => "desc", title => "Description", width => 40, align => "<" },
{ name => "deb", title => "Debet", width => 10, align => ">" },
{ name => "crd", title => "Credit", width => 10, align => ">" },
]);
# Start the reporter.
$rep->start;
# Add data, row by row.
$rep->add({ acct => 1234, desc => "Received", deb => "242.33" });
$rep->add({ acct => 5678, desc => "Paid", crd => "699.45" });
$rep->add({ acct => 1259, desc => "Taxes", deb => "12.00", crd => "244.00" });
$rep->add({ desc => "TOTAL", deb => "254.33", crd => "943.45" });
# Finish the reporter.
$rep->finish;
DESCRIPTION
Data::Report is a flexible, plugin-driven reporting framework. It makes it easy to define
reports that can be produced in text, HTML and CSV. Textual ornaments like extra empty
lines, dashed lines, and cell lines can be added in a way similar to HTML style sheets.
The Data::Report framework consists of three parts:
The plugins
Plugins implement a specific type of report. Standard plugins provided are
"Data::Report::Plugin::Text" for textual reports, "Data::Report::Plugin::Html" for
HTML reports, and "Data::Report::Plugin::Csv" for CSV (comma-separated) files.
Users can, and are encouraged, to develop their own plugins to handle different styles
and types of reports.
The base class
The base class "Data::Report::Base" implements the functionality common to all
reporters, plus a number of utility functions the plugins can use.
The factory
The actual "Data::Report" module is a factory that creates a reporter for a given
report type by selecting the appropriate plugin and returning an instance thereof.
BASIC METHODS
Note that except for the "create" method, all other methods are actually handled by the
plugins and their base class.
create
Reporter objects are created using the class method "create". This method takes a hash (or
hashref) of arguments to initialise the reporter object.
The actual reporter object is implemented by one of the plugin modules, selected by the
"type" argument. Standard plugins are provided for "text", "HTML" and "CSV" report types.
The default type is "text".
When looking for a plugin to support report type "foo", the "create" method will first try
to load a module "My::Package::Foo" where "My::Package" is the invocant class. If this
module cannot be loaded, it will fall back to "Data::Report::Plugin::Foo". Note that,
unless subclassed, the current class will be "Data::Report".
All other initialisation arguments correspond to attribute setting methods provided by the
plugins. For example, the hypothetical call
my $rpt = Data::Report->create(foo => 1, bar => "Hello!");
is identical to:
my $rpt = Data::Report->create;
$rpt->set_foo(1);
$rpt->set_bar("Hello!");
You can choose any combination at your convenience.
start
This method indicates that all setup has been completed, and starts the reporter. Note
that no output is generated until the "add" method is called.
"start" takes no arguments.
Although this method could be eliminated by automatically starting the reporter upon the
first call to "add", it turns out that an aplicit "start" makes the API much cleaner and
makes it easier to catch mistakes.
add
This method adds a new entry to the report. It takes one single argument, a hash ref of
column names and the corresponding values. Missing columns are left blank.
In addition to the column names and values, you can add the special key "_style" to
designate a particular style for this entry. What that means depends on the plugin that
implements this reporter. For example, the standard HTML reporter plugin prefixes the
given style with "r_" to form the class name for the row. The style name should be a
simple name, containing letters, digits and underscores, starting with a letter.
Example
$rpt->add({ date => "2006-04-31",
amount => 1000,
descr => "First payment",
_style => "plain" });
finish
This method indicates that report generation is complete. After this, you can call "start"
again to initiate a new report.
"finish" takes no arguments.
close
This is a convenience method. If the output stream was set up by the reporter itself (see
"set_output", below), the stream will be closed. Otherwise, this method will be a no-op.
"close" takes no arguments.
ATTRIBUTE HANDLING METHODS
get_type
The reporter type.
set_layout
This is the most important attribute, since it effectively defines the report layout.
This method takes one argument, an array reference. Each element of the array is a hash
reference that corresponds to one column in the report. The order of elements definines
the order of the columns in the report, but see "set_fields" below.
The following keys are possible in the hash reference:
"name"
The name of this column. The name should be a simple name, containing letters, digits
and underscores, starting with a letter.
The standard HTML reporter plugin uses the column name to form a class name for each
cell by prefixing with "c_". Likewise, the classes for the table headings will be
formed by prefixing the column names with "h_". See "ADVANCED EXAMPLES", below.
"title"
The title of this column. This title is placed in the column heading.
"width"
The width of this column. Relevant for textual reporters only.
By default, if a value does not fit in the given width, it will be spread over
multiple rows in a pseudo-elegant way. See also the "truncate" key, below.
"align"
The alignment of this column. This can be either "<" for left-aligned columns, or ">"
to indicate a right-aligned column.
"truncate"
If true, the values in this column will be truncated to fit the width of the column.
Relevant for textual reporters only.
set_style
This method can be used to set an arbitrary style (a string) whose meaning depends on the
implementing plugin. For example, a HTML plugin could use this as the name of the style
sheet to use.
The name should be a simple name, containing letters, digits and underscores, starting
with a letter.
get_style
Returns the style, or "default" if none.
set_output
Designates the destination for the report. The argument can be
a SCALAR reference
All output will be appended to the designated scalar.
an ARRAY reference
All output lines will be pushed onto the array.
a SCALAR
A file will be created with the given name, and all output will be written to this
file. To close the file, use the "close" method described above.
anything else
Anything else will be considered to be a file handle, and treated as such.
set_stylist
The stylist is a powerful method to control the appearance of the report at the row and
cell level. The basic idea is taken from HTML style sheets. By using a stylist, it is
possible to add extra spaces and lines to rows and cells in a declarative way.
When used, the stylist should be a reference to a possibly anonymous subroutine with three
arguments: the reporter object, the style of a row (as specified with "_style" in the
"add" method), and the name of a column as defined in the layout. For table headings, the
row name "_head" is used.
The stylist routine will be repeatedly called by the reporter to obtain formatting
properties for rows and cells. It should return either nothing, or a hash reference with
properties.
When called with only the "row" argument, it should return the properties for this row.
When called with row equal to "*" and a column name, it should return the properties for
the given column.
When called with a row and a column name, it should return the properties for the given
row/column (cell).
All appropriate properties are merged to form the final set of properties to apply.
The following row properties are recognised. Between parentheses the backends that support
them.
"skip_before"
(Text) Produce an empty line before printing the current row.
"skip_after"
(Text) Produce an empty line after printing the current row, but only if other data
follows.
"line_before"
(Text) Draw a line of dashes before printing the current row.
"line_after"
(Text) Draw a line of dashes after printing the current row.
"cancel_skip"
(Text) Cancel the effect of a pending "skip_after"
"ignore"
(All) Ignore this row. Useful for CSV backends where only the raw data matters, and
not the totals and such.
The following cell properties are recognised. Between parentheses the backends that
support them.
"indent"
(Text) Indent the contents of this cell with the given amount.
"wrap_indent"
(Text) Indent wrapped contents of this cell with the given amount.
"truncate"
(Text) If true, truncate the contents of this cell to fit the column width.
"line_before"
(Text) Draw a line in the cell before printing the current row. The value of this
property indicates the symbol to use to draw the line. If it is 1, dashes are used.
"line_after"
(Text) Draw a line in the cell after printing the current row. The value of this
property indicates the symbol to use to draw the line. If it is 1, dashes are used.
"raw_html"
(Html) Do not escape special HTML characters, allowing pre-prepared HTML code to be
placed in the output. Use with care.
"ignore"
(All) Ignore this column. Note that to prevent surprising results, the column must be
ignored in all applicable styles, including the special style "_head" that controls
the heading.
"class"
(Html) Class name to be used for this cell. Default class name is "h_CNAME" for table
headings and "c_CNAME" for table rows, where CNAME is the name of the column.
Example:
$rep->set_stylist(sub {
my ($rep, $row, $col) = @_;
unless ( $col ) {
return { line_after => 1 } if $row eq "total";
return;
}
return { line_after => 1 } if $col eq "amount";
return;
});
Each reporter provides a standard (dummy) stylist called "_std_stylist". Overriding this
method is equivalent to using "set_stylist".
get_stylist
Returns the current stylist, if any.
set_topheading
Headings consist of two parts, the top heading, and the standard heading. Bij default, the
top heading is empty, and the standard heading has the names of the columns with a
separator line (depnendent on the plugin used).
This method can be used to designate a subroutine that will provide the top heading of the
report.
Example:
$rpt->set_topheading(sub {
my $self = shift;
$self->_print("Title line 1\n");
$self->_print("Title line 2\n");
$self->_print("\n");
});
Note the use of the reporter provided "_print" method to produce output.
When subclassing a reporter, a method "_top_heading" can be defined to provide the top
heading. This is equivalent to an explicit call to "set_topheading", but doesn't need to
be repeatedly and explicitly executed for each new reporter.
get_topheading
Returns the current top heading routine, if any.
set_heading
This method can be used to designate a subroutine that provides the standard heading of
the report.
In normal cases using this method is not necessary, since setting the top heading will be
sufficient.
Each reporter plugin provides a standard heading, implemented in a method called
"_std_header". This is the default value for the "heading" attribute. A user-defined
heading can use
$self->SUPER::_std_header;
to still get the original standard heading produced.
Example:
$rpt->set_heading(sub {
my $self = shift;
$self->_print("Title line 1\n");
$self->_print("Title line 2\n");
$self->_print("\n");
$self->SUPER::_std_heading;
$self->_print("\n");
});
Note the use of the reporter provided "_print" method to produce output.
When subclassing a reporter, the method "_std_heading" can be overridden to provide a
customized top heading. This is equivalent to an explicit call to "set_topheading", but
doesn't need to be repeatedly and explicitly executed for each new reporter.
get_heading
Returns the current standard heading routine, if any.
set_fields
This method can be used to define what columns (fields) should be included in the report
and the order they should appear. It takes an array reference with the names of the
desired columns.
Example:
$rpt->set_fields([qw(descr amount date)]);
get_fields
Returns the current set of selected columns.
set_width
This method defines the width for one or more columns. It takes a hash reference with
column names and widths. The width may be an absolute number, a relative number (to
increase/decrease the width, or a percentage.
Example:
$rpt->set_width({ amount => 10, desc => '80%' });
get_widths
Returns a hash with all column names and widths.
ADVANCED EXAMPLES
This example subclasses Data::Report with an associated plugin for type "text". Note the
use of overriding "_top_heading" and "_std_stylist" to provide special defaults for this
reporter.
package POC::Report;
use base qw(Data::Report);
package POC::Report::Text;
use base qw(Data::Report::Plugin::Text);
sub _top_heading {
my $self = shift;
$self->_print("Title line 1\n");
$self->_print("Title line 2\n");
$self->_print("\n");
}
sub _std_stylist {
my ($rep, $row, $col) = @_;
if ( $col ) {
return { line_after => "=" }
if $row eq "special" && $col =~ /^(deb|crd)$/;
}
else {
return { line_after => 1 } if $row eq "total";
}
return;
}
It can be used as follows:
my $rep = POC::Report::->create(type => "text");
$rep->set_layout
([ { name => "acct", title => "Acct", width => 6 },
{ name => "desc", title => "Report", width => 40, align => "<" },
{ name => "deb", title => "Debet", width => 10, align => "<" },
{ name => "crd", title => "Credit", width => 10, align => ">" },
]);
$rep->start;
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "normal" });
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "normal" });
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "special"});
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "total" });
$rep->finish;
The output will look like:
Title line 1
Title line 2
Acct Report Debet Credit
------------------------------------------------------------------------
one two three four
one two three four
one two three four
========== ==========
one two three four
------------------------------------------------------------------------
This is a similar example for a HTML reporter:
package POC::Report;
use base qw(Data::Report);
package POC::Report::Html;
use base qw(Data::Report::Plugin::Html);
sub start {
my $self = shift;
$self->{_title1} = shift;
$self->{_title2} = shift;
$self->{_title3} = shift;
$self->SUPER::start;
}
sub _top_heading {
my $self = shift;
$self->_print("<html>\n",
"<head>\n",
"<title>", $self->_html($self->{_title1}), "</title>\n",
'<link rel="stylesheet" href="css/', $self->get_style, '.css">', "\n",
"</head>\n",
"<body>\n",
"<p class=\"title\">", $self->_html($self->{_title1}), "</p>\n",
"<p class=\"subtitle\">", $self->_html($self->{_title2}), "<br>\n",
$self->_html($self->{_title3}), "</p>\n");
}
sub finish {
my $self = shift;
$self->SUPER::finish;
$self->_print("</body>\n</html>\n");
}
Note that it defines an alternative "start" method, that is used to pass in additional
parameters for title fields.
The method "_html" is a convenience method provided by the framework. It returns its
argument with sensitive characters escaped by HTML entities.
It can be used as follows:
package main;
my $rep = POC::Report::->create(type => "html");
$rep->set_layout
([ { name => "acct", title => "Acct", width => 6 },
{ name => "desc", title => "Report", width => 40, align => "<" },
{ name => "deb", title => "Debet", width => 10, align => "<" },
{ name => "crd", title => "Credit", width => 10, align => ">" },
]);
$rep->start(qw(Title_One Title_Two Title_Three_Left&Right));
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "normal" });
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "normal" });
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "normal" });
$rep->add({ acct => "one", desc => "two", deb => "three", crd => "four", _style => "total" });
$rep->finish;
The output will look like this:
<html>
<head>
<title>Title_One</title>
<link rel="stylesheet" href="css/default.css">
</head>
<body>
<p class="title">Title_One</p>
<p class="subtitle">Title_Two<br>
Title_Three_Left&Right</p>
<table class="main">
<tr class="head">
<th align="left" class="h_acct">Acct</th>
<th align="left" class="h_desc">Report</th>
<th align="right" class="h_deb">Debet</th>
<th align="right" class="h_crd">Credit</th>
</tr>
<tr class="r_normal">
<td align="left" class="c_acct">one</td>
<td align="left" class="c_desc">two</td>
<td align="right" class="c_deb">three</td>
<td align="right" class="c_crd">four</td>
</tr>
<tr class="r_normal">
<td align="left" class="c_acct">one</td>
<td align="left" class="c_desc">two</td>
<td align="right" class="c_deb">three</td>
<td align="right" class="c_crd">four</td>
</tr>
<tr class="r_normal">
<td align="left" class="c_acct">one</td>
<td align="left" class="c_desc">two</td>
<td align="right" class="c_deb">three</td>
<td align="right" class="c_crd">four</td>
</tr>
<tr class="r_total">
<td align="left" class="c_acct">one</td>
<td align="left" class="c_desc">two</td>
<td align="right" class="c_deb">three</td>
<td align="right" class="c_crd">four</td>
</tr>
</table>
</body>
</html>
See also the examples in "t/09poc*.t".
AUTHOR
Johan Vromans, "<jvromans at squirrel.nl>"
BUGS
Disclaimer: This module is derived from actual working code, that I turned into a generic
CPAN module. During the process, some features may have become unstable, but that will be
cured in time. Also, it is possible that revisions of the API will be necessary when new
functionality is added.
Please report any bugs or feature requests to "bug-data-report at rt.cpan.org", or through
the web interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Data-Report>. I will
be notified, and then you'll automatically be notified of progress on your bug as I make
changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Data::Report (user API)
perldoc Data::Report::Base (plugin writer documentation)
You can also look for information at:
• RT: CPAN's request tracker
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Data-Report>
• CPAN Ratings
<http://cpanratings.perl.org/d/Data-Report>
• Search CPAN
<http://search.cpan.org/dist/Data-Report>
ACKNOWLEDGEMENTS
COPYRIGHT & LICENSE
Copyright 2006,2008 Squirrel Consultancy, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.