/ 
Sah-Schemas-Str-0.017
River stage one • 5 direct dependents • 8 total dependents
/ Sah::Schema::str_or_code

NAME

Sah::Schema::str_or_code - String or coderef (if string is of the form `sub {...}`)

VERSION

This document describes version 0.017 of Sah::Schema::str_or_code (from Perl distribution Sah-Schemas-Str), released on 2023-12-20.

SYNOPSIS

Sample data and validation results against this schema

""  # valid

"a"  # valid

{}  # INVALID (Not a string)

"sub {}"  # valid

"sub{\"foo\"}"  # valid

"sub {"  # valid (Becomes a string)

"sub {1=2}"  # INVALID (Code does not compile)

Using with Data::Sah

To check data against this schema (requires Data::Sah):

use Data::Sah qw(gen_validator);
my $validator = gen_validator("str_or_code*");
say $validator->($data) ? "valid" : "INVALID!";

The above validator returns a boolean result (true if data is valid, false if otherwise). To return an error message string instead (empty string if data is valid, a non-empty error message otherwise):

my $validator = gen_validator("str_or_code", {return_type=>'str_errmsg'});
my $errmsg = $validator->($data);

# a sample valid data
$data = "";
my $errmsg = $validator->($data); # => ""

# a sample invalid data
$data = "sub {1=2}";
my $errmsg = $validator->($data); # => "Error in compiling code: Can't modify constant item in scalar assignment at (eval 2747) line 1, at EOF\n"

Often a schema has coercion rule or default value rules, so after validation the validated value will be different from the original. To return the validated (set-as-default, coerced, prefiltered) value:

my $validator = gen_validator("str_or_code", {return_type=>'str_errmsg+val'});
my $res = $validator->($data); # [$errmsg, $validated_val]

# a sample valid data
$data = "";
my $res = $validator->($data); # => ["",""]

# a sample invalid data
$data = "sub {1=2}";
my $res = $validator->($data); # => ["Error in compiling code: Can't modify constant item in scalar assignment at (eval 2760) line 1, at EOF\n","sub {1=2}"]

Data::Sah can also create validator that returns a hash of detailed error message. Data::Sah can even create validator that targets other language, like JavaScript, from the same schema. Other things Data::Sah can do: show source code for validator, generate a validator code with debug comments and/or log statements, generate human text from schema. See its documentation for more details.

Using with Params::Sah

To validate function parameters against this schema (requires Params::Sah):

use Params::Sah qw(gen_validator);

sub myfunc {
    my @args = @_;
    state $validator = gen_validator("str_or_code*");
    $validator->(\@args);
    ...
}

Using with Perinci::CmdLine::Lite

To specify schema in Rinci function metadata and use the metadata with Perinci::CmdLine (Perinci::CmdLine::Lite) to create a CLI:

# in lib/MyApp.pm
package
  MyApp;
our %SPEC;
$SPEC{myfunc} = {
    v => 1.1,
    summary => 'Routine to do blah ...',
    args => {
        arg1 => {
            summary => 'The blah blah argument',
            schema => ['str_or_code*'],
        },
        ...
    },
};
sub myfunc {
    my %args = @_;
    ...
}
1;

# in myapp.pl
package
  main;
use Perinci::CmdLine::Any;
Perinci::CmdLine::Any->new(url=>'/MyApp/myfunc')->run;

# in command-line
% ./myapp.pl --help
myapp - Routine to do blah ...
...

% ./myapp.pl --version

% ./myapp.pl --arg1 ...

Using on the CLI with validate-with-sah

To validate some data on the CLI, you can use validate-with-sah utility. Specify the schema as the first argument (encoded in Perl syntax) and the data to validate as the second argument (encoded in Perl syntax):

% validate-with-sah '"str_or_code*"' '"data..."'

validate-with-sah has several options for, e.g. validating multiple data, showing the generated validator code (Perl/JavaScript/etc), or loading schema/data from file. See its manpage for more details.

Using with Type::Tiny

To create a type constraint and type library from a schema (requires Type::Tiny as well as Type::FromSah):

package My::Types {
    use Type::Library -base;
    use Type::FromSah qw( sah2type );

    __PACKAGE__->add_type(
        sah2type('str_or_code*', name=>'StrOrCode')
    );
}

use My::Types qw(StrOrCode);
StrOrCode->assert_valid($data);

DESCRIPTION

Either string or coderef is accepted.

If string matches the regex qr/\Asub\s*\{.*\}\z/s, then it will be eval'ed into a coderef. If the code fails to compile, the value will be rejected. Note that this means you accept arbitrary code from the user to execute! Please make sure first and foremost that this is acceptable in your case.

Currently string is eval'ed in the main package, without use strict or use warnings.

This schema is handy if you want to accept string or coderef from the command-line.

What's the difference between this schema and code_from_str (from Sah::Schemas::Code)? Both this schema and code_from_str accept string, but code_from_str will directly compile any input string while this schema will only convert string to code if it is in the form of sub { ... }. In other words, this schema can output either string or coderef, while code_from_str will always produce coderef.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Sah-Schemas-Str.

SOURCE

Source repository is at https://github.com/perlancar/perl-Sah-Schemas-Str.

SEE ALSO

Sah::Schema::str_or_re

Sah::Schema::str_or_re_or_code

Sah::Schema::code_from_str

AUTHOR

perlancar <perlancar@cpan.org>

CONTRIBUTING

To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

% prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE

This software is copyright (c) 2023, 2022, 2020 by perlancar <perlancar@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Sah-Schemas-Str

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.