String::Template - Fills in string templates from hash of fields
version 0.23
use String::Template; my %fields = ( num => 2, str => 'this', date => 'Feb 27, 2008' ); my $template = "...<num%04d>...<str>...<date:%Y/%m/%d>...\n"; print expand_string($template, \%fields); #prints: "...0002...this...2008/02/27..."
Generate strings based on a template.
Replacement tokens are denoted with angle brackets. That is <fieldname> is replaced by the values in the \%fields hash reference provided.
Some special characters can be used after the field name to impose formatting on the fields:
%Treat like a sprintf format, example: <int%02d>.
:Treat like a "strftime" in POSIX format, example <date:%Y-%m-%d>.
The field is parsed by Date::Parse, so it can handle any format that it can handle.
![version 0.05]
#Treat like args to substr; example <str#0,2> or <str#4>.
{ and }[version 0.20]
The { character is specially special, since it allows fields to contain additional characters that are not intended for formatting. This is specially useful for specifying additional content inside a field that may not exist in the hash, and which should be entirely replaced with the empty string.
This makes it possible to have templates like this:
my $template = '<name><nick{ "%s"}><surname{ %s}>';
my $mack = { name => 'Mack', nick => 'The Knife' };
my $jack = { name => 'Jack', surname => 'Sheppard' };
expand_string( $template, $mack ); # Returns 'Mack "The Knife"'
expand_string( $template, $jack ); # Returns 'Jack Sheppard'
All functions are exported by default, or by request, except for "expand_hash"
my $str = expand_string($template, \%fields); my $str = expand_string($template, \%fields, $undef_flag);
Fills in a simple template with values from a hash, replacing tokens with the value from the hash $fields{fieldname}.
Handling of undefined fields can be controlled with $undef_flag. If it is false (default), undefined fields are simply replaced with an empty string. If set to true, the field is kept verbatim. This can be useful for multiple expansion passes.
[version 0.08]
my $str = expand_stringi($template, \%fields); my $str = expand_stringi($template, \%fields, $undef_flag);
expand_stringi works just like "expand_string", except that tokens and hash keys are treated case insensitively.
[version 0.06]
my @missing = missing_values($template, \%fields); my @missing = missing_values($template, \%fields, $dont_allow_undefs);
Checks to see if the template variables in a string template exist in a hash. Set $dont_allow_undefs to 1 to also check to see if the values for all such keys are defined.
Returns a list of missing keys or an empty list if no keys were missing.
[version 0.07]
my $status = expand_hash($hash); my $status = expand_hash($hash, $maxdepth);
Expand a hash of templates/values. This function will repeatedly replace templates in the values of the hash with the values of the hash they reference, until either all <fieldname> templates are gone, or it has iterated $maxdepth times (default 10).
Returns undef if there are unexpanded templates left, otherwise true.
This function must be explicitly exported.
String::Format performs a similar function, with a different syntax.
Original author: Brian Duggan
Current maintainer: Graham Ollis <plicease@cpan.org>
Contributors:
Curt Tilmes
Jeremy Mates (thirg, JMATES)
José Joaquín Atria
This software is copyright (c) 2015 by Brian Duggan.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.