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Module Version: 2.00   Source  


String::Validator - A Collection of Routines for validating and transforming strings


version 2.00

Description ^

A Collection of Routines for validating and transforming strings

Why String::Validator

You have a string and you need to know if it is what you need it to be. You just wasted three hours before you realized it was going to take longer than you thought and just started to poke around cpan to find something to use instead. The String Validator Collection is what you are looking for.

Since as often as not you're not just validating strings, but also trying to get them into a specific format, many String::Validator Modules will do this.

The String::Validator Module

The Core Module, String::Validator is empty. It contains some common documentation, and all other String::Validator Modules are dependencies to install it. You can type cpanm String::Validator to install the current version of all of the Modules.

Methods Common to String::Validator Modules ^

The New Method

The new method for String-Validators takes as an argument a hash of parameters, these will be different for each module. See the specific Module's Documentation.

The Postive and Negative Method

The negative method IsNot_Valid will return 0 (false) for a valid string and the reason as a string for an invalid one.

The positive method Is_Valid will return 1 (true) and 0 (false). To find out why a string failed use the errstr method.

Both Is_Valid and IsNot_Valid will take either one string or two strings as arguments. If two strings are provided they are compared. When two strings are provided and do not match only 1 error is observed, because String::Validator cannot know which (if either) to continue evaluating. If called subsequently the String() method will return Null and the errorcnt() method will return 1.

errstr, errcnt

errcnt returns the number of errors seen on the last call to Is/IsNot_Valid. errstr returns a string describing the errors encountered.

String, Reformatting

The String method always returns the internal representation of the last string evaluated by Is/IsNot_Valid. The exceptions are that a new String::Validator Object will return a NULL value, as it will following a mismatch error when the string is passed twice. String-Validators may provide reformat methods appropriate to their purpose and will be documented in their own POD.


 my $Validator = String::Validator::Demo->new(
    format => 'fake', min_length => 6, max_length => 17 ) ;
 if ( $Validator->IsNot_Valid('ThisString') { do something }
 unless ( $Validator->IsNot_Valid('ThatString') { die $Validator->errstr() }
 if ( $Validator->IsNot_Valid('ThisString', 'RepeatThisString') { do something }
 say  $Validator->String ;

CamelCase lowercase

The base class String::Validator::Common provides both the CamelCase and lowercase versions of the methods it provides for use by the end user of the inheriting module, this is done to make it even more convenient.

Customizing with Language and Custom Messages. ^

As of Version 2.0 the ->new Method to takes two optional parameters: language and custom_messages, which are expected to be a hash of message names and messages, in some cases the messages are code_refs. String::Validator::Language contains translation modules. You may also pass a hash over-riding the messages of a String::Validator with custom_messages. If you want to write customzed messages in a Validator Module, obtain a list of the messages, by using Data::Dumper or Data::Printer against an object of that validator; without any languages loaded.

 my $TranslatedValidator =
         language=> String::Validator::Language::CHACKOBSA->new,
         custom_messages => {
                somevalidator_sandworm => 'Shai-Halud'});

See String::Validator::Language for a list of available languages.

Making Validator Better ^

Everything Validator does is a waste of time (if you had to do it yourself). So if you find you've wasted time validating something that fits with the Validator theme, write it up and send it in. If you think Validator does a poor job of something, send a better solution. If you already made a module even better, just wrap it up as a Validator.

If you use String Validator in a Language other than English and don't see your language in String::Validator::Language, or that it is missing some messages, Submit a translation patch for String::Validator::Language.

Bug Reports and Patches ^

Please submit Bug Reports and Patches via


John Karr <>


This software is Copyright (c) 2018 by John Karr.

This is free software, licensed under:

  The GNU General Public License, Version 3, June 2007
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