Data::Sah - Fast and featureful data structure validation
This document describes version 0.29 of Data::Sah (from Perl distribution Data-Sah), released on 2014-06-30.
Non-OO interface:
use Data::Sah qw( normalize_schema gen_validator ); # generate a validator for schema my $v = gen_validator(["int*", min=>1, max=>10]); # validate your data using the generated validator say "valid" if $v->(5); # valid say "valid" if $v->(11); # invalid say "valid" if $v->(undef); # invalid say "valid" if $v->("x"); # invalid # generate validator which reports error message string, in Indonesian my $v = gen_validator(["int*", min=>1, max=>10], {return_type=>'str', lang=>'id_ID'}); say $v->(5); # '' say $v->(12); # 'Data tidak boleh lebih besar dari 10' # (in English: 'Data must not be larger than 10') # normalize a schema my $nschema = normalize_schema("int*"); # => ["int", {req=>1}, {}]
OO interface (more advanced usage):
use Data::Sah; my $sah = Data::Sah->new; # get perl compiler my $pl = $sah->get_compiler("perl"); # compile schema into Perl code my $cd = $pl->compile(schema => $schema, ...);
This module, Data::Sah, implements compilers for producing Perl and JavaScript validators, as well as translatable human description text from Sah schemas. Compiler approach is used instead of interpreter for faster speed.
The generated validator code can run without this module.
Some features are not implemented yet:
General
def/subschema
expression
buf type
date/datetime type
obj: meths, attrs properties
.prio, .err_msg, .ok_err_msg attributes
.result_var attribute
BaseType: if, prefilters, postfilters, check, prop, check_prop clauses
HasElems: each_elem, each_index, check_each_elem, check_each_index, exists clauses
HasElems: len, elems, indices properties
hash: check_each_key, check_each_value, allowed_keys_re, forbidden_keys_re clauses
array: uniq clauses
human compiler
markdown output
perl compiler
js compiler
None exported by default.
Normalize $schema.
$schema
Can also be used as a method.
Generate validator code for $schema. Can also be used as a method. Known options (unknown options will be passed to Perl schema compiler):
accept_ref => BOOL (default: 0)
Normally the generated validator accepts data, as in:
$res = $vdr->($data); $res = $vdr->(42);
If this option is set to true, validator accepts reference to data instead, as in:
$res = $vdr->(\$data);
This allows $data to be modified by the validator (mainly, to set default value specified in schema). For example:
my $data; my $vdr = gen_validator([int => {min=>0, max=>10, default=>5}], {accept_ref=>1}); my $res = $vdr->(\$data); say $res; # => 1 (success) say $data; # => 5
source => BOOL (default: 0)
If set to 1, return source code string instead of compiled subroutine. Usually only needed for debugging (but see also $Log_Validator_Code and LOG_SAH_VALIDATOR_CODE if you want to log validator source code).
$Log_Validator_Code
LOG_SAH_VALIDATOR_CODE
A mapping of compiler name and compiler (Data::Sah::Compiler::*) objects.
Create a new Data::Sah instance.
Get compiler object. Data::Sah::Compiler::$name will be loaded first and instantiated if not already so. After that, the compiler object is cached.
Data::Sah::Compiler::$name
Example:
my $plc = $sah->get_compiler("perl"); # loads Data::Sah::Compiler::perl
Normalize a schema, e.g. change int* into [int => {req=>1}], as well as do some sanity checks on it. Returns the normalized schema if succeeds, or dies on error.
int*
[int => {req=>1}]
Can also be used as a function.
Normalize a clause set, e.g. change {"!match"=>"abc"} into {"match"=>"abc", "match.op"=>"not"}. Produce a shallow copy of the input clause set hash.
{"!match"=>"abc"}
{"match"=>"abc", "match.op"=>"not"}
Normalize a variable name in expression into its fully qualified/absolute form.
Not yet implemented (pending specification).
For example:
[int => {min => 10, 'max=' => '2*$min'}]
$min in the above expression will be normalized as schema:clauses.min.
schema:clauses.min
Use the Perl compiler to generate validator code. Can also be used as a function. See the documentation as a function for list of known options.
Data::Sah::Type::* roles specify Sah types, e.g. Data::Sah::Type::bool specifies the bool type. It can also be used to name distributions that introduce new types, e.g. Data-Sah-Type-complex which introduces complex number type.
Data::Sah::Type::bool
Data-Sah-Type-complex
Data::Sah::FuncSet::* roles specify bundles of functions, e.g. <Data::Sah::FuncSet::Core> specifies the core/standard functions.
Data::Sah::Compiler::$LANG:: namespace is for compilers. Each compiler might further contain <::TH::*> and <::FSH::*> subnamespaces to implement appropriate functionalities, e.g. Data::Sah::Compiler::perl::TH::bool is the bool type handler for the Perl compiler and Data::Sah::Compiler::perl::FSH::Core is the Core funcset handler for Perl compiler.
Data::Sah::Compiler::perl::TH::bool
Data::Sah::Compiler::perl::FSH::Core
Data::Sah::TypeX::$TYPENAME::$CLAUSENAME namespace can be used to name distributions that extend an existing Sah type by introducing a new clause for it. See Data::Sah::Manual::Extending for an example.
Data::Sah::Lang::$LANGCODE namespaces are for modules that contain translations. They are further organized according to the organization of other Data::Sah modules, e.g. Data::Sah::Lang::en_US::Type::int or Data::Sah::Lang::en_US::TypeX::str::is_palindrome.
Data::Sah::Lang::en_US::TypeX::str::is_palindrome
Sah::Schema:: namespace is reserved for modules that contain bundles of schemas. For example, Sah::Schema::CPANMeta contains the schema to validate CPAN META.yml. Sah::Schema::Int contains various schemas for integers such as pos_int, int8, uint32. Sah::Schema::Sah contains the schema for Sah schema itself.
Sah::Schema::CPANMeta
pos_int
int8
uint32
See also Sah::FAQ.
Data::Schema is the old incarnation of this module, deprecated since 2011.
There are enough incompatibilities between the two (some different syntaxes, renamed clauses). Also, some terminology have been changed, e.g. "attribute" become "clauses", "suffix" becomes "attributes". This warrants a new name.
Compared to Data::Schema, Sah always compiles schemas and there is much greater flexibility in code generation (can generate data term, can generate code to validate multiple schemas, etc). There is no longer hash form, schema is either a string or an array. Some clauses have been renamed (mostly, commonly used clauses are abbreviated, Huffman encoding thingy), some removed (usually because they are replaced by a more general solution), and new ones have been added.
If you use Data::Schema, I recommend you migrate to Data::Sah as I will not be developing Data::Schema anymore. Sorry, there's currently no tool to convert your Data::Schema schemas to Sah, but it should be relatively straightforward.
See Sah::FAQ.
You probably do not reuse the compiled schema, e.g. you continually destroy and recreate Data::Sah object, or repeatedly recompile the same schema. To gain the benefit of compilation, you need to keep the compiled result and use the generated Perl code repeatedly.
// if first element is an integer, require the array to contain only integers, // otherwise require the array to contain only strings. ["array", {"min_len": 1, "of=": "[is_int($_[0]) ? 'int':'str']"}]
Currently no, Data::Sah does not support expression on clauses that contain other schemas. In other words, dynamically generated schemas are not supported. To support this, if the generated code needs to run independent of Data::Sah, it needs to contain the compiler code itself (or an interpreter) to compile or evaluate the generated schema.
However, an eval_schema() Sah function which uses Data::Sah can be trivially declared and target the Perl compiler.
eval_schema()
If you use the OO interface, e.g.:
# generate perl code my $cd = $plc->compile(schema=>..., ...);
then the generated code is in $cd->{result} and you can just print it.
$cd->{result}
If you generate validator using gen_validator(), you can set environment LOG_SAH_VALIDATOR_CODE or package variable $Log_Validator_Code to true and the generated code will be logged at trace level using Log::Any. The log can be displayed using, e.g., Log::Any::App:
gen_validator()
% LOG_SAH_VALIDATOR_CODE=1 TRACE=1 \ perl -MLog::Any::App -MData::Sah=gen_validator \ -e '$sub = gen_validator([int => min=>1, max=>10])'
Sample output:
normalized schema=['int',{max => 10,min => 1},{}] schema already normalized, skipped normalization validator code: 1|do { 2| require Scalar::Util::Numeric; 3| sub { 4| my ($data) = @_; 5| my $_sahv_res = | 7| # skip if undef 8| (!defined($data) ? 1 : | 10| (# check type 'int' 11| (Scalar::Util::Numeric::isint($data)) | 13| && | 15| (# clause: min 16| ($data >= 1)) | 18| && | 20| (# clause: max 21| ($data <= 10)))); | 23| return($_sahv_res); 24| }}
Pass the <return_type="str">> to get an error message string on error, or <return_type="full">> to get a hash of detailed error messages. Note also that the error messages are translateable (e.g. use LANG or lang=>... option. For example:
<return_type=
LANG
lang=>...
my $v = gen_validator([int => between => [1,10]], {return_type=>"str"}); say "$_: ", $v->($_) for 1, "x", 12;
will output:
1: "x": Input is not of type integer 12: Must be between 1 and 10
@...
It shows the path to data item that fails the validation, e.g.:
my $v = gen_validator([array => of => [int=>min=>5], {return_type=>"str"}); say $v->([10, 5, "x"]);
prints:
@2: Input is not of type integer
which means that the third element (subscript 2) of the array fails the validation. Another example:
my $v = gen_validator([array => of => [hash=>keys=>{a=>"int"}]]); say $v->([{}, {a=>1.1}]);
@1/a: Input is not of type integer
If you are generating Perl code from schema, you can pass debug=>1 option so the code contains logging (Log::Any-based) and other debugging information, which you can display. For example:
debug=>1
% TRACE=1 perl -MLog::Any::App -MData::Sah=gen_validator -E' $v = gen_validator([array => of => [hash => {req_keys=>["a"]}]], {return_type=>"str", debug=>1}); say "Validation result: ", $v->([{a=>1}, "x"]);'
... [spath=[]]skip if undef ... [spath=[]]check type 'array' ... [spath=['of']]clause: {"of":["hash",{"req_keys":["a"]}]} ... [spath=['of']]skip if undef ... [spath=['of']]check type 'hash' ... [spath=['of','req_keys']]clause: {"req_keys":["a"]} ... [spath=['of']]skip if undef ... [spath=['of']]check type 'hash' ... Validation result: [spath=of]@1: Input is not of type hash
Data::Sah offers some options in code generation. Beside compiling the validator code into a subroutine, there are also some other options. Examples:
Dist::Zilla::Plugin::Rinci::Validate
This plugin inserts the generated code (without the sub { ... } wrapper) to validate the content of %args right before # VALIDATE_ARG or # VALIDATE_ARGS like below:
sub { ... }
%args
# VALIDATE_ARG
# VALIDATE_ARGS
$SPEC{foo} = { args => { arg1 => { schema => ..., req=>1 }, arg2 => { schema => ... }, }, ... }; sub foo { my %args = @_; # VALIDATE_ARGS }
The schemas will be retrieved from the Rinci metadata ($SPEC{foo} above). This means, subroutines in your built distribution will do argument validation.
$SPEC{foo}
Perinci::Sub::Wrapper
This module is part of the Perinci family. What the module does is basically wrap your subroutine with a wrapper code that can include validation code (among others). This is a convenient way to add argument validation to an existing subroutine/code.
(perl compiler) Replace smartmatch because of its inconsistent behavior
<$data ~~ ["x", 1]> will do string comparison, while <$data ~~ [1, "x"]> or even <$data ~~ ["1", "x"]> will do a numeric comparison.
<$data ~~ ["x", 1]
<$data ~~ [1, "x"]
<$data ~~ ["1", "x"]
Params::Validate is very fast, although minimal. Data::Rx, Kwalify, Data::Verifier, Data::Validator, JSON::Schema, Validation::Class.
For Moo/Mouse/Moose stuffs: Moose type system, MooseX::Params::Validate, Type::Tiny, among others.
Form-oriented: Data::FormValidator, FormValidator::Lite, among others.
Please visit the project's homepage at https://metacpan.org/release/Data-Sah.
Source repository is at https://github.com/sharyanto/perl-Data-Sah.
Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Data-Sah
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.
Steven Haryanto <stevenharyanto@gmail.com>
This software is copyright (c) 2014 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.
To install Data::Sah, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Data::Sah
CPAN shell
perl -MCPAN -e shell install Data::Sah
For more information on module installation, please visit the detailed CPAN module installation guide.