NAME

Dist::Zilla::Plugin::Rinci::Validate - Insert argument validator code in output code

VERSION

version 0.09

SYNOPSIS

In dist.ini:

[Rinci::Validate]

In your module:

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

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

output will be something like:

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

    my $arg1 = $args{arg1}; require Scalar::Util; my $arg_err; (($arg1 //= 3), 1) && ((defined($arg1)) ? 1 : (($err_arg1 = 'TMPERRMSG: required data not specified'),0)) && ((Scalar::Util::looks_like_number($arg1) =~ /^(?:1|2|9|10|4352)$/) ? 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 inserts argument validation code into your module source code, at location marked with # VALIDATE_ARG or # VALIDATE_ARGS. Validation code is compiled using Data::Sah from Sah schemas specified in args property in Rinci function metadata in the module.

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 _perinci.sub.wrapper.validate_args => 0 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, 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.

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.

TODO

• Use PPI instead of fragile regex.

• Option to not compress validator code to a single line.

• Option to configure variable name to store validation ($arg_err).

• Option to reuse code for the same schema.

AUTHOR

Steven Haryanto <stevenharyanto@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2013 by Steven Haryanto.

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

cpanm Dist::Zilla::Plugin::Rinci::Validate

perl -MCPAN -e shell
install Dist::Zilla::Plugin::Rinci::Validate