ODF::lpOD::Common(3)

NAME
ODF::lpOD::Common - Common utilities provided by the Perl lpOD library

DESCRIPTION
This manual page describes miscellaneous functions and auxiliary features of the lpOD Perl implementation that are not directly linked to the lpOD functional specification.

Data conversion and type checking utilities
The utilities introduced in this section are implemented as exported functions. They may be used without package or object reference.

is_true(value),

Returns "TRUE" if the given value may be regarded as true (in the Perl lpOD implementation). The usual Perl true values are interpreted as "TRUE", with a few exceptions. The strings 'false', 'no', and 'off', like 0, "undef", and the empty string, are regarded as "FALSE".

Note that the standard ODF false value is the string 'false'; so it's correctly interpreted as false by is_true().

The common constants "TRUE" and "FALSE" (corresponding to 1 and 0) may be used by the applications.

is_false(value)

Returns "TRUE" if the given value is either a regular Perl false value or one of the strings 'false', 'no', 'off'. Returns "FALSE" otherwise.

odf_boolean(value)

Translates into an ODF-compliant boolean value (i.e. 'true' or 'false') an arbitrary value. The result may be used as the value of any ODF boolean attribute. Examples:

        say odf_boolean(0);             # "false"
        say odf_boolean(undef);         # "false"
        say odf_boolean("All right");   # "true"
        say odf_boolean('no');          # "false"
        say odf_boolean(123);           # "true"

is_odf_datatype(type)

Returns "TRUE" if the given argument is the name of a valid ODF data type for table cells or variable fields, "FALSE" otherwise. For example, the first instruction below returns "TRUE" and the second one returns "FALSE":

        $check1 = is_odf_datatype('float');
        $check2 = is_odf_datatype('complexType');

odf_value(value, type)

Converts the given value according to the given type (which must be a regular ODF data type), and checks it if the value is already in ODF format.

The following example formats the current system date so the result may be used as the value of a date field in a document:

        $odf_date = odf_value(time(), 'date');

The following instruction returns "2011-09-30T19:55:03", i.e. it translates a numeric time into a ISO-8601, ODF-compliant alphanumeric date:

        $d = odf_value(1317405303, 'date');

This function returns "undef" if the given value is not compatible with the given type.

Note: this function doesn't work for any type in the present version.

iso_date(time)

Translates a numeric "time" into an ISO-8601, ODF-compliant date.

Without argument, returns the current date in ODF-compliant format.

numeric_date(odf_date)

Translates an ODF-formatted date (ISO-8601) into a Perl computable "time" value.

translate_coordinates(alpha_spreadsheet_coordinates)

Returns the zero-based row number and column number according to a string representing spreadsheet-like coordinates. For example "A1" gives (0, 0), "Z10" gives (9, 25), and so on. Note that the row number comes first in the result, while the column letter comes first in the argument.

translate_range(alpha_spreadsheet_range)

Returns the zero-based numeric coordinates of the two positions that define a range in a spreadsheet, according to an alphanumeric range expression. As an example, "B4:F12" gives (3, 1, 11, 5). Note that the given string must be separated in two part by a colon; each part is translated according to the same logic as translate_coordinates(), producing a list of 4 values.

External file control
These functions are provided for specific physical operations of ODF document parts.

file_parse(file_path)

This utility is a variant of the standard "File::Basename::fileparse" function, mainly for internal use by lpOD.

In scalar context, extracts the full file name (i.e. including the suffix, if any) from the given string, that is supposed to be a full path (URL or local).

In array context, returns the path, then the full name (including the suffix, if any), then the suffix itself (without the dot). Beware that such a behavior is not exactly the same as "File::Basename::fileparse".

The following example will return "("logo.png", "/usr/share/images/", "png")":

        ($base, $path, $suffix) = file_parse("/usr/share/images/logo.png");

This one will return "("mydoc.odt", "http://mydomain.com/", "odt")":

        ($base, $path, $suffix) = file_parse("http://mydomain.com/mydoc.odt");

This last one will just return "mydoc.odt":

        $base = file_parse("http://mydomain.com/mydoc.odt");

file_type(file_path)

Returns the MIME type of the resource corresponding to the given file path, or "undef" (without error) if the resource is not available, if the "File::Type" module is not installed, or if the resource is not supported by "File::Type".

Beware: This function uses the "File::Type" logic and doesn't determine the type according to the file name suffix.

image_size(image [, document => $doc])

Returns the size, expressed in points ("pt"), of the image corresponding to the given resource, or "undef" (without error) if the resource is not available, or if the image type is not supported by "Image::Size".

The argument may be a local file path, a regular URL, a file handle, or the reference of a in-memory buffer (scalar reference). If a "document" optional parameter is provided, its value must be a "odf_document" object and the first argument is interpreted as a document part identifier; in such a situation, the image resource is looked for in the given document, allowing the user to get the orginal size of an image file previously loaded in the ODF file by another application.

In scalar context, the return value (if defined) is an array ref of 2 strings (the width and the height), each one containing a numeric value and terminated by "pt". This array ref may be directly used in order to set the size of a rectangular shape through the lpOD API (typically, in order to adjust the size of the object that will contain the image). In array context, image_size() returns a list of 2 numeric values, namely the width and the height (both in points, but without the "pt" suffix).

General configuration
Some methods are provided by the "lpod" pseudo-object in order to get or set some configuration parameters.

Installation information

The "info" method returns some information about the current lpOD installation, as a string in scalar context, or as a hash in array context.

For example, the instruction 'say scalar lpod->info' produces an information string containing "ODF::lpOD", the CPAN package build date, and the current installation path, like in the example below:

 ODF::lpOD 1.106 2011-02-15T15:07:39 /usr/lib/perl5/site_perl/5.10.0/ODF/lpOD

There is a "signature" method that produces the same result as the scalar value of "info".

The "installation_path" method returns the path of the "ODF::lpOD" module installation in the user's file system.

Color name translation

Knowing that lpOD allows the user to specify color codes for various objects, some codes may be replaced by symbolic names. A few hundreds of symbolic names and the corresponding values are defined by default, according to a standard Xorg/RGB vocabulary. The user may add custom color names thanks to load_color_map(), whose argument is the full path of a RGB text file whose format complies with the typical Xorg "rgb.txt".

The unload_color_map() removes every color name for the current process, while load_color_map() without argument restores the default name/code mapping. load_color_map() may be used repeatedly in order to cumulate several RGB files.

Two explicit color translation functions are provided:

•   color_code(name) : returns the color code corresponding to the given color name, if known; ex: "color_code('antique white')" produces '#faebd7'; returns "undef" if the name is unknown;

•   color_name(code) : returns a symbolic name, if any, corresponding to the given color code; ex: color_name('#faebd7') returns 'antique white'; returns "undef" if no name is known for this code.

Beware that different names may correspond to the same code, so at the end of the sequence below, $a may differ from $b:

        $c = color_code($a);
        $b = color_name($c);

Character sets handling

lpOD is (as soon as possible) locale- and platform- neutral, so its default input and output character set is always "utf8" unless the user makes an explicit alternative selection.

All the text/attribute oriented methods of the "odf_element" may automatically convert the processed content from or to the local character set of the user. The default character set is "utf8". If the user provides non-utf8 content, the input character set must be declared using the set_input_charset(), that is a lpOD installation method (not a document method). Example:

        lpod->set_input_charset('iso-8859-1');

If the user wants to get non-utf8 outputs from any content-extraction method, the output character set must be declared in a similar way through set_output_charset():

        lpod->set_output_charset('iso-8859-1');

Input and output charsets may be changed at any time, so the user may, for example, successively insert texts using various encodings (that could prove useful for document generation from heterogeneous sources).

Beware that the input and output charsets are not always the same. The user could want, for example, populate a document from non-utf8 web pages, and in the same session export some content from the same to document to local log files or the console, that may require "utf8" or a another character set (depending of the user's locale).

The currently active character sets may be checked using get_input_charset() and get_output_charset() (as methods of the "lpod" pseudo-object).

For the list of supported character sets, see the documentation of the Perl "Encode" module.

Warning information

The "lpod->debug()" method, when called with "TRUE" of "FALSE" as argument, switches on or off the debug flag. If this flag is on, the call stack is displayed with every error message of the lpOD API.

A so-called alert() function may be used by the applications with one or more strings as arguments; if the debug flag is "FALSE", it just produces a "warn" (with a line break) for each argument; if the debug flag is "TRUE", it's a wrapper for Carp::cluck() (so it outputs the call stack trace).

AUTHOR/COPYRIGHT
Developer/Maintainer: Jean-Marie Gouarne <http://jean.marie.gouarne.online.fr> Contact: jmgdoc@cpan.org

Copyright (c) 2010 Ars Aperta, Itaapy, Pierlis, Talend. Copyright (c) 2014 Jean-Marie Gouarne.

This work was sponsored by the Agence Nationale de la Recherche (<http://www.agence-nationale-recherche.fr>).

License: GPL v3, Apache v2.0 (see LICENSE).