From Code to Community: Sponsoring The Perl and Raku Conference 2025 Learn more

 / 
Sah-Schemas-JSON-0.007
River stage three • 11 direct dependents • 157 total dependents
/ Sah::Schema::json_or_str

NAME

Sah::Schema::json_or_str - A JSON-encoded data or string

VERSION

This document describes version 0.007 of Sah::Schema::json_or_str (from Perl distribution Sah-Schemas-JSON), released on 2022-11-15.

SYNOPSIS

Sample data and validation results against this schema


            

              
              
""  # valid (Empty string, left as-is as string)
1  # valid
"null"  # valid (JSON-decoded and becomes undef), becomes undef
"\"null\""  # valid (JSON-decoded into string), becomes "null"
"[1,2,3,{}]"  # valid (JSON-decoded into array), becomes [1,2,3,{}]
"[1,2"  # valid (Left as-is as string since it is invalid JSON (missing closing square bracket))
"[1,2,]"  # valid (Left as-is as string since it is invalid JSON (dangling comma))
[1,2]  # valid (Not coerced, already an array)
{}  # valid (Not coerced, already a hash)
undef  # valid (Not coerced, already an undef)

Using with Data::Sah

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


            

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

The above schema 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("json_or_str", {return_type=>'str_errmsg'});
my $errmsg = $validator->($data);
# a sample valid data
$data = undef;
my $errmsg = $validator->($data); # => ""

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


            

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

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("json_or_str*");
    $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 => ['json_or_str*'],
        },
        ...
    },
};
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 with Type::Tiny

To create a type constraint and type library from a schema:


            

              
              
package My::Types {
    use Type::Library -base;
    use Type::FromSah qw( sah2type );
    __PACKAGE__->add_type(
        sah2type('$sch_name*', name=>'JsonOrStr')
    );
}
use My::Types qw(JsonOrStr);
JsonOrStr->assert_valid($data);

DESCRIPTION

You can use this schema if you want to accept any data (a data structure or simple scalar), and if user supplies a defined string e.g. in a command-line script as command-line argument or option, it will be tried to be JSON-decoded first. If the string does not contain valid JSON, it will be left as-is as string.

This schema is convenient on the command-line where you want to accept data structure via command-line argument or option. But you have to be careful when you want to pass a string like null, true, false; you have to quote it to "null", "true", "false" to prevent it being decoded into undef or boolean values.

See also related schema: json_str, str::encoded_json, str::escaped_json.

HOMEPAGE

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

SOURCE

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

SEE ALSO

Sah::Schema::json_str

Sah::Schema::str::encoded_json

Sah::Schema::str::escaped_json

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) 2022, 2021 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-JSON

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.