SYNOPSIS 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}, {}] normalize_schema(["int*", min=>0]); # => ["int", {min=>0, 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 => ["int*", min=>0]); say $cd->{result}; will print something like: # req #0 (defined($data)) && # check type 'int' (Scalar::Util::Numeric::isint($data)) && (# clause: min ($data >= 0)) To see the full validator code (with sub {} and all), you can do something like: % LOG=1 LOG_SAH_VALIDATOR_CODE=1 TRACE=1 perl -MLog::Any::App -MData::Sah=gen_validator -E'gen_validator(["int*", min=>0])' which will print log message like: normalized schema=['int',{min => 0,req => 1},{}] validator code: 1|do { 2| require Scalar::Util::Numeric; 3| sub { 4| my ($data) = @_; 5| my $_sahv_res = | 7| # req #0 8| (defined($data)) | 10| && | 12| # check type 'int' 13| (Scalar::Util::Numeric::isint($data)) | 15| && | 17| (# clause: min 18| ($data >= 0)); | 20| return($_sahv_res); 21| }} STATUS Some features are not implemented yet: * def/subschema * expression * buf type * date/datetime type * obj: meths, attrs properties * .prio, .err_msg, .ok_err_msg attributes * .result_var attribute * BaseType: if, prefilters, postfilters, check, prop, check_prop clauses * HasElems: each_elem, each_index, check_each_elem, check_each_index, exists clauses * HasElems: len, elems, indices properties * hash: check_each_key, check_each_value, allowed_keys_re, forbidden_keys_re clauses * array: uniq clauses * human compiler: markdown output * markdown output DESCRIPTION This module, Data::Sah, implements compilers for producing Perl and JavaScript validators, as well as translatable human description text from Sah schemas. Compiler approach is used instead of interpreter for faster speed. The generated validator code can run without this module. EXPORTS None exported by default. normalize_schema($schema) => ARRAY Normalize $schema. Can also be used as a method. gen_validator($schema, \%opts) => CODE (or STR) 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). ATTRIBUTES compilers => HASH A mapping of compiler name and compiler (Data::Sah::Compiler::*) objects. VARIABLES $Log_Validator_Code (bool, default: 0) ENVIRONMENT LOG_SAH_VALIDATOR_CODE METHODS new() => OBJ Create a new Data::Sah instance. $sah->get_compiler($name) => OBJ Get compiler object. Data::Sah::Compiler::$name will be loaded first and instantiated if not already so. After that, the compiler object is cached. Example: my $plc = $sah->get_compiler("perl"); # loads Data::Sah::Compiler::perl $sah->normalize_schema($schema) => HASH 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. Can also be used as a function. Note: this functionality is implemented in Data::Sah::Normalize (distributed separately in Data-Sah-Normalize). Use that module instead if you just need normalizing schemas, to reduce dependencies. $sah->normalize_clset($clset[, \%opts]) => HASH 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. Can also be used as a function. $sah->normalize_var($var) => STR 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. $sah->gen_validator($schema, \%opts) => CODE 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. MODULE ORGANIZATION 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::FuncSet::* roles specify bundles of functions, e.g. specifies the core/standard functions. Data::Sah::Compiler::$LANG:: namespace is for compilers. Each compiler might further contain <::TH::*> and <::FSH::*> subnamespaces to implement appropriate functionalities, e.g. Data::Sah::Compiler::perl::TH::bool is the bool type handler for the Perl compiler and Data::Sah::Compiler::perl::FSH::Core is the Core funcset handler for Perl compiler. Data::Sah::TypeX::$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. 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. FAQ See also Sah::FAQ. Relation to Data::Schema? 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 customize data term, code can return boolean or error message string or detailed hash, 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. Comparison to {JSON::Schema, Data::Rx, Data::FormValidator, ...}? See Sah::FAQ. Why is it so slow? 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. Can I generate another schema dynamically from within the schema? For example: // 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. How to display the validator code being generated? Use the source => 1 option in gen_validator(). 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. If you generate validator using gen_validator(), you can set environment LOG_SAH_VALIDATOR_CODE or package variable $Log_Validator_Code to true and the generated code will be logged at trace level using Log::Any. The log can be displayed using, e.g., Log::Any::App: % LOG_SAH_VALIDATOR_CODE=1 TRACE=1 \ perl -MLog::Any::App -MData::Sah=gen_validator \ -e '$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| }} Lastly, you can also use validate-with-sah CLI utility from the App::SahUtils distribution (use the --show-code option). How to show the validation error message? The validator only returns true/false! 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: 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 What does the @... prefix that is sometimes shown on the error message mean? 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}]); prints: @1/a: Input is not of type integer How to show the process of validation by the compiled code? 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: % 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"]);' will output: ... [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 What else can I do with the compiled code? 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: $SPEC{foo} = { args => { arg1 => { schema => ..., req=>1 }, arg2 => { schema => ... }, }, ... }; sub foo { my %args = @_; # VALIDATE_ARGS } The schemas will be retrieved from the Rinci metadata ($SPEC{foo} above). This means, subroutines in your built distribution will do argument validation. * 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. SEE ALSO Other compiled validators Other interpreted validators 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.