NAME Data::Validate::Struct - Validate recursive Hash Structures SYNOPSIS use Data::Validate::Struct; my $validator = new Data::Validate::Struct($reference); if ( $validator->validate($config_hash_reference) ) { print "valid\n"; } else { print "invalid " . $validator->errstr() . "\n"; } DESCRIPTION This module validates a config hash reference against a given hash structure in contrast to Data::Validate in which you have to check each value separately using certain methods. This hash could be the result of a config parser or just any hash structure. Eg. the hash returned by XML::Simple could be validated using this module. You may also use it to validate CGI input, just fetch the input data from CGI, map it to a hash and validate it. Data::Validate::Struct uses some of the methods exported by Data::Validate, so you need to install it too. PREDEFINED BUILTIN DATA TYPES int Match a simple integer number. hex Match a hex value. oct Match an octagonal value. number Match a decimal number, it may contain , or . and may be signed. word Match a single word, _ and - are tolerated. line Match a line of text - no newlines are allowed. text Match a whole text(blob) including newlines. This expression is very loosy, consider it as an alias to any. regex Match a perl regex using the operator qr(). Valid examples include: qr/[0-9]+/ qr([^%]*) qr{\w+(\d+?)} Please note, that this doesn't mean you can provide here a regex against config options must match. Instead this means that the config options contains a regex. eg: grp = qr/root|wheel/ regex would match the content of the variable 'grp' in this example. To add your own rules for validation, use the type() method, see below. uri Match an internet URI. ipv4 Match an IPv4 address. cidrv4 The same as above including cidr netmask (/24), IPv4 only, eg: 10.2.123.0/23 Note: shortcuts are not supported for the moment, eg: 10.10/16 will fail while it is still a valid IPv4 cidr notation for a network address (short for 10.10.0.0/16). Must be fixed in Regex::Common. ipv6 Match an IPv6 address. Some examples: 3ffe:1900:4545:3:200:f8ff:fe21:67cf fe80:0:0:0:200:f8ff:fe21:67cf fe80::200:f8ff:fe21:67cf ff02:0:0:0:0:0:0:1 ff02::1 cidrv6 The same as above including cidr netmask (/64), IPv6 only, eg: 2001:db8:dead:beef::1/64 2001:db8::/32 quoted Match a text quoted with single quotes, eg: 'barbara is sexy' hostname Match a valid hostname, it must qualify to the definitions in RFC 2396. resolvablehost Match a hostname resolvable via dns lookup. Will fail if no dns is available at runtime. path Match a valid absolute path, it won't do a stat() system call. This will work on any operating system at runtime. So this one: C:\Temp will return TRUE if running on WIN32, but FALSE on FreeBSD! fileexists Look if value is a file which exists. Does a stat() system call. user Looks if the given value is an existent user. Does a getpwnam() system call. group Looks if the given value is an existent group. Does a getgrnam() system call. port Match a valid tcp/udp port. Must be a digit between 0 and 65535. vars Matches a string of text containing variables (perl style variables though) eg: $user is $attribute I am $(years) old Missing ${points} points to succeed MIXED TYPES If there is an element which could match more than one type, this can be matched by using the pipe sign `|' to separate the types. { name => 'int | number' } There is no limit on the number of types that can be checked for, and the check is done in the sequence written (first the type 'int', and then 'number' in the example above). OPTIONAL ITEMS If there is an element which is optional in the hash, you can use the type 'optional' in the type. The 'optional' type can also be mixed with ordinary types, like: { name => 'text | optional' } The type 'optional' can be placed anywhere in the type string. NEGATIVE MATCHING In some rare situations you might require a negative match. So a test shall return TRUE if a particular value does NOT match the given type. This might be usefull to prevent certain things. To achieve this, you just have to prepend one of the below mentioned types with the keyword no. Example: $ref = { path => 'novars' } This returns TRUE if the value of the given config hash does NOT contain ANY variables. VALIDATOR STRUCTURE The expected structure must be a standard perl hash reference. This hash may look like the config you are validating but instead of real-live values it contains types that define of what type a given value has to be. In addition the hash may be deeply nested. In this case the validated config must be nested the same way as the reference hash. Example: $reference = { user => 'word', uid => 'int' }; The following config would be validated successful: $config = { user => 'HansDampf', uid => 92 }; this one not: $config = { user => 'Hans Dampf', uid => 'nine' }; ^ ^^^^ | | | +----- is not a number +---------------------- space not allowed For easier writing of references you yould use a configuration file parser like Config::General or Config::Any, just write the definition using the syntax of such a module, get the hash of it and use this hash as validation reference. NESTED HASH STRUCTURES You can also match against nested structures. Data::Validate::Struct iterates into the given config hash the same way as the reference hash looks like. If the config hash doesn't match the reference structure, perl will throw an error, which Data::Validate::Struct catches and returns FALSE. Given the following reference hash: $ref = { 'b1' => { 'b2' => { 'b3' => { 'item' => 'int' } } } } Now if you validate it against the following config hash it will return TRUE: $cfg = { 'b1' => { 'b2' => { 'b3' => { 'item' => '100' } } } } If you validate it for example against this hash, it will return FALSE: $cfg = { 'b1' => { 'b2' => { 'item' => '100' } } } SUBROUTINES/METHODS validate($config) $config must be a hash reference you'd like to validate. It returns a true value if the given structure looks valid. If the return value is false (0), then the error message will be written to the variable $!. type(%types) You can enhance the validator by adding your own rules. Just add one or more new types using a simple hash using the type() method. Values in this hash can be regexes or anonymous subs. Example: $v3->type( ( address => qr(^\w+\s\s*\d+$), list => sub { my $list = $_[0]; my @list = split /\s*,\s*/, $list; if (scalar @list > 1) { return 1; } else { return 0; } } ) ); In this example we add 2 new types, 'list' and 'address', which are really simple. 'address' is a regex which matches a word followed by an integer. 'list' is a subroutine which gets called during evaluation for each option which you define as type 'list'. Such subroutines must return a true value in order to produce a match. A negative/reverse match is automatically added as well, see NEGATIVE MATCHING. Regexes will be executed exactly as given. No flags or ^ or $ will be used by the module. Eg. if you want to match the whole value from beginning to the end, add ^ and $, like you can see in our 'address' example above. debug() Enables debug output which gets printed to STDERR. errstr() Returns the last error, which is useful to notify the user about what happened. EXAMPLES Take a look to t/run.t for lots of examples. CONFIGURATION AND ENVIRONMENT No environment variables will be used. SEE ALSO I recommend you to read the following documentations, which are supplied with perl: perlreftut Perl references short introduction. perlref Perl references, the rest of the story. perldsc Perl data structures intro. perllol Perl data structures: arrays of arrays. Data::Validate common data validation methods. Data::Validate::IP common data validation methods for IP-addresses. LICENSE AND COPYRIGHT Copyright (c) 2007-2013 Thomas Linden This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. BUGS AND LIMITATIONS Some implementation details as well as the API may change in the future. This will no more happen if entering a stable release (starting with 1.00). To submit use http://rt.cpan.org. INCOMPATIBILITIES None known. DIAGNOSTICS To debug Data::Validate::Struct use debug() or the perl debugger, see perldebug. For example to debug the regex matching during processing try this: perl -Mre=debug yourscript.pl DEPENDENCIES Data::Validate::Struct depends on the module Data::Validate, Data::Validate:IP, Regexp::Common, File::Spec and File::stat. TODO * Add support for ranges, in fact Regexp::Common or Data::Validate already supports this, but Data::Validate::Struct currently doesn't support parameters for types. * Perhaps add code validation too, for example we could have a type 'perl' which tries to evaluate the given value. On the other side this may lead to security holes - so I might never do it. * Plugin System * Possibly add support for grammars. This might be much more powerful than regular expressions, say: { name => 'expr OP expr | expr' } or something like this. AUTHOR Thomas Linden Thanks to David Cantrell for his helpful hints. VERSION 0.07