/ 
Dist-Zilla-Plugin-Rinci-EmbedValidator-0.251
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/ Dist::Zilla::Plugin::Rinci::EmbedValidator

NAME

Dist::Zilla::Plugin::Rinci::EmbedValidator - Embed schema validator code in built code

VERSION

This document describes version 0.251 of Dist::Zilla::Plugin::Rinci::EmbedValidator (from Perl distribution Dist-Zilla-Plugin-Rinci-EmbedValidator), released on 2020-06-05.

SYNOPSIS

In dist.ini:

[Rinci::EmbedValidator]

In your module:

$SPEC{foo} = {
    args => {
        arg1 => { schema => ['int*', default=>3] },
        arg2 => { },
    },
};
sub foo {
    my %args = @_;

    my $arg1 = $args{arg1}; # VALIDATE_ARG
    ...
}

The built version will become something like:

$SPEC{foo} = {
    args => {
        arg1 => { schema => ['int*', default=>3] },
        arg2 => { },
    },
};
sub foo {
    my %args = @_;

    my $arg1 = $args{arg1}; { require Scalar::Util::Numeric; my $arg_err; (($arg1 //= 3), 1) && ((defined($arg1)) ? 1 : (($err_arg1 = 'TMPERRMSG: required data not specified'),0)) && ((Scalar::Util::Numeric::isint($arg1)) ? 1 : (($err_arg1 = 'TMPERRMSG: type check failed'),0)); return [400, "Invalid value for arg1: $err_arg1"] if $arg1; } # VALIDATE_ARG
    ...
}

You can also validate all arguments:

sub foo {
    my %args = @_; # VALIDATE_ARGS

    ...
}

DESCRIPTION

This plugin generates schema validation code then embeds the code into your module source code, at location marked with # VALIDATE_ARG or # VALIDATE_ARGS. The validation code is generated by Data::Sah from Sah schemas specified in args property in Rinci function metadata in the module.

TODO: Embed result/return validation code.

USAGE

To validate a single argument, in your module:

sub foo {
    my %args = @_;
    my $arg1 = $args{arg1}; # VALIDATE_ARG

The significant part that is interpreted by this module is my $arg1. Argument name is taken from the lexical variable's name (in this case, arg1). Argument must be defined in the args property of the function metadata. If argument name is different from lexical variable name, then you need to say:

my $f = $args->{frobnicate}; # VALIDATE_ARG frobnicate

To validate all arguments of the subroutine, you can say:

sub foo {
    my %args = @_; # VALIDATE_ARGS

There should only be one VALIDATE_ARGS per subroutine.

If you use this plugin, and you plan to wrap your functions too using Perinci::Sub::Wrapper (or through Perinci::Access, Perinci::CmdLine, etc), you might also want to put x.perinci.sub.wrapper.disable_validate_args => 1 attribute into your function metadata, to instruct Perinci::Sub::Wrapper to skip generating argument validation code when your function is wrapped, as argument validation is already done by the generated code.

If there is an unvalidated argument, this plugin will emit a warning notice. To skip validating an argument (silence the warning), you can use:

sub foo {
    my %args = @_;
    my $arg1 = $args{arg1}; # NO_VALIDATE_ARG

or:

sub foo {
    # NO_VALIDATE_ARGS

FAQ

Rationale for this plugin?

This plugin is an alternative to Perinci::Sub::Wrapper and Dist::Zilla::Plugin::Rinci::Wrap, at least when it comes to validating arguments. Perinci::Sub::Wrapper can also generate argument validation code (among other things), but it is done during runtime and can add to startup overhead (compiling complex schemas for several subroutines can take up to 100ms or more, on my laptop). Using this plugin, argument validation code is generated during building of your distribution.

Using this plugin also makes sure that argument is validated whether your subroutine is wrapped or not. Using this plugin also avoids wrapping and adding nest level, if that is not to your liking.

Instead of using this plugin, you can use wrapping either by using Perinci::Exporter or by calling Perinci::Sub::Wrapper's wrap_sub directly.

Another alternative to using this plugin is Dist::Zilla::Plugin::Rinci::GenSchemaV. Instead of embedding the validator code directly in the same file, this plugin creates Sah::SchemaV::YOUR_MODULE_NAME modules and put the generated validator code there. Perinci::CmdLine::Lite can use this validator code instead of generating the validator code dynamically with Data::Sah, saving some startup time.

But why use Rinci metadata or Sah schema?

In short, adding Rinci metadata to your subroutines allows various tools to do useful stuffs, relieving you from doing those stuffs manually. Using Sah schema allows you to write validation code succintly, and gives you the ability to automatically generate Perl/JavaScript/error messages from the schema.

See their respective documentation for more details.

But the generated code looks ugly!

Admittedly, yes. Validation source code is formatted as a single long line to avoid modifying line numbers, which is desirable when debugging your modules. An option to not compress everything as a single line might be added in the future.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Dist-Zilla-Plugin-Rinci-EmbedValidator.

SOURCE

Source repository is at https://github.com/perlancar/perl-Dist-Zilla-Plugin-Rinci-EmbedValidator.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Dist-Zilla-Plugin-Rinci-EmbedValidator

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.

SEE ALSO

Alternative approach to generating validator code: Dist::Zilla::Plugin::Rinci::Wrap, Dist::Zilla::Plugin::Rinci::GenSchemaV

Data::Sah::Manual::ParamsValidating

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012 by 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.