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:
<cfg>
grp = qr/root|wheel/
</cfg>
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
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
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.
$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.
$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
$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.
You can also add reversive types, which are like all other types but
start with no. The validator does a negative match in such a case,
thus you will have a match if a variable does not match the type.
The builtin type 'novars' is such a type.
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.
ARRAYS
Arrays must be handled in a special way, just define an array with two elements and the second empty. The config will only validated against the first element in the array.
We assume all elements in an array must have the same structure.
Example for array of hashes:
$reference = {
[
{
user => 'word',
uid => 'int'
},
{} # empty 2nd element
]
};
Example of array of values:
$reference = {
var => [ 'int', '' ]
}
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.
LICENSE AND COPYRIGHT
Copyright (c) 2007 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, Regexp::Common, File::Spec and File::stat.
TODO
{ name => 'int|number' }
{ name => 'expr OP expr | expr' }
or something like this.
AUTHOR
Thomas Linden <tlinden |AT| cpan.org>
Thanks to David Cantrell for his helpful hints.
VERSION
0.06