Embperl::Form::Validate - Form validation with server- and client-side support.
This modules is developed to do form validation for you. It works on the server side by checking the posted form data and it generates client side script functions, to validate the form values, as far as possible, before they are send to the server, to avoid another server roundtrip.
Also it has the best support for Embperl, it should also work outside of Embperl e.g. with CGI.pm or mod_perl.
It can be extended by new validation rules for additional syntaxes (e.g. US zip codes, German Postleitzahlen, number plates, iso-3166 2-digit language or country codes, etc.)
Each module has the ability to rely it's answer on parameters like e.g. the browser, which caused the request for or submitted the form.
The module fully supports internationalisation. Any message can be provided in multiple languages and it makes use of Embperl's multilanguage support.
use Embperl::Form::Validate; my $epf = new Embperl::Form::Validate($rules, $form_id); $epf->add_rule('fnord', $fnord_rules); # validate the form values and returns error information, if any my $result = $epf -> validate ; # Does the form content validate? print 'Validate: ' . ($result?'no':'yes'); # validate the form values and reaturn all error messages, if any my @errors = $epf->validate_messages($fdat, $pref); # Get the code for a client-side form validation according to the # rules given to new: $epf -> get_script_code ;
The following methods are available:
Constructor for a new form validator. Returns a reference to a Embperl::Form::Validate object.
should be a reference to an array of rules, see "RULES" elsewhere in this document for details.
should be the name (im HTML) or id (in XHTML) parameter of the form tag, which has to be verified.It\'s e.g. used for generating the right path in the JavaScript DOM. It defaults to 'forms[0]' which should be the first form in your page.
language to use when no messages are available in the desired language. Defaults to 'en'.
Adds rules $field_rules for a (new) field $field to the validator, e.g.
$epf->add_rule([ -key => 'fnord', -type => 'Float', -max => 1.3, -name => 'Fnord' ]);
The new rule will be appended to the end of the list of rules.
See "RULES" elsewhere in this document.
Does the server-side form validation.
should be a hash reference to all postend form values. It defaults to %fdat of the current Embperl page.
can contain addtional information for the validation process. At the moment the keys language and default_language are recognized. language defaults to the language set by Embperl. default_language defaults to the one given with new.
language
default_language
new
The method verifies the content $fdat according to the rules given to the Embperl::Form::Validate constructor and added by the add_rule() method and returns an array refernce to error informations. If there is no error it returns undef. Each element of the returned array contains a hash with the following keys:
key into $fdat which caused the error
message id
object reference to the Validate object which was used to validate the field
human readable name, if any. Maybe a hash with multiple languages.
field specific messages, if any. Maybe a hash with multiple languages.
array with parameters which should subsituted inside the message
Converts one item returned by validate into a error message
Item returned by validate
Preferences (see validate)
Validate the form content and returns the error messages if any. See validate for details.
Returns the script code necessary to do the client-side validation. Put the result between <SCRIPT> and </SCRIPT> tags inside your page. It will contain a function that is named epform_validate_<name_of_your_form> where <name_of_your_form> is replaced by the form named you have passed to new. You should call this function in the onSubmit of your form. Example:
epform_validate_<name_of_your_form
onSubmit
<script> [+ do { local $escmode = 0 ; $epf -> get_script_code } +] </script> <form name="foo" action="POST" onSubmit="return epform_validate_foo()"> .... </form>
The functions and methods expect the named data structures as follows:
The $rules array contains a list of tests to perform. Alls the given tests are process sequenzially. You can group tests together, so when one test fails the remaining of the same group are not processed.
[ [ -key => 'lang', -name => 'Language' required => 1, length_max => 5, ], [ -key => 'from', -type => 'Date', emptyok => 1, ], -key => ['foo', 'bar'] required => 1, ]
All items starting with a dash are control elements, while all items without a dash are tests to perform.
gives the key in the passed form data hash which should be tested. -key is normaly the name given in the HTML name attribute within a form field. -key can also be a arrayref, in which case only one of the given keys must statisfy the following test to succeed.
-key
is a human readable name that should be used in error messages. Can be hash with multiple languages, e.g.
-name => { 'en' => 'date', 'de' => 'Datum' }
specfify to not use the standard tests, but the ones for a special type. For example there is a type Number which will replaces all the comparsions by numeric ones instead of string comparisions. You may add your own types by wrting a module that contains the necessary test and dropping it under Embperl::Form::Validate::<Typename>. The -type directive also can verfiy that the given data has a valid format for the type.
Number
At the moment the only types that are available is Default and Number. The first is the default and need not to be specified. If you are writing new type make sure to send them back, so they can be part of the next distribution.
Default
Used to give messages which should be used when the test fails. This message overrides the standart messages provided by Embperl::Form::Validate and by Embperls message management. Can also be a hash with messages for multiple languages.
stops further validation after the first error is found
continues validation in the same group, also a error was found
you can place a arrayref with tests at any point in the rules list. The array will be considered as a group and the default is the stop processing of a group as soon as the first error is found and continue with processing with the next rules.
The following test are currently defined:
The $pref hash (reference) contains information about a single form request or submission, e.g. the browser version, which made the request or submission and the language in which the error messages should be returned. See also validate
For a descriptions of the error codes, validate is returning see validate
See also Embperl.
my $fdat = { foo => 'foobar', bar => 'baz', baz => 49, fnord => 1.2 };
This example simply validates the form input when you hit submit. If your input is correct, the form is redisplay with your input, otherwise the error message is shown. If you turn off JavaScript the validation is still done one the server-side. Any validation for which no JavaScript validation is defined (like regex matches), only the server-side validation is performed.
<html> <head> [- use Embperl::Form::Validate ; $epf = Embperl::Form::Validate -> new ( [ [ -key => 'name', -name => 'Name', required => 1, length_min => 4, ], [ -key => 'id', -name => 'Id', -type => 'Number', gt => 0, lt => 10, ], [ -key => 'email', -msg => 'This is not a valid E-Mail address', must_contain_one_of => '@.', matches_regex => '..+@..+\\...+', length_min => 8, ], [ -key => 'msg', -name => 'Message', emptyok => 1, length_min => 10, ] ]) ; if ($fdat{check}) { $errors = $epf -> validate_messages ; } -] <script> [+ do { local $escmode = 0 ; $epf -> get_script_code } +] </script> </head> <body> <h1>Embperl Example - Input Form Validation</h1> [$if @$errors $] <h3>Please correct the following errors</h3> [$foreach $e (@$errors)$] <font color="red">[+ $e +]</font><br> [$endforeach$] [$else$] <h3>Please enter your data</h3> [$endif$] <form action="formvalidation.htm" method="GET" onSubmit="return epform_validate_forms_0_()"> <table> <tr><td><b>Name</b></td> <td><input type="text" name="name"></td></tr> <tr><td><b>Id (1-9)</b></td> <td><input type="text" name="id"></td></tr> <tr><td><b>E-Mail</b></td> <td><input type="text" name="email"></td></tr> <tr><td><b>Message</b></td> <td><input type="text" name="msg"></td></tr> <tr><td colspan=2><input type="submit" name="check" value="send"></td></tr> </table> </form> <p><hr> <small>Embperl (c) 1997-2002 G.Richter / ecos gmbh <a href="http://www.ecos.de">www.ecos.de</a></small> </body> </html>
See also eg/x/formvalidation.htm
Axel Beckert (abe@ecos.de) Gerald Richter (richter@dev.ecos.de)
To install Embperl, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Embperl
CPAN shell
perl -MCPAN -e shell install Embperl
For more information on module installation, please visit the detailed CPAN module installation guide.