NAME WWW::Form - Object-oriented module for HTML form input validation and display SYNOPSIS Simple and extendable module that allows developers to handle HTML form input validation and display flexibly and consistently. DESCRIPTION This module: * provides functionality to handle all of the various types of HTML form inputs * handles populating form inputs with user entered data or progammer specified default values * provides support for validation of user entered input * handles presenting customizable error feedback to users * should be easy to extend, the WWW::Form module is designed to be inherited from, so you can add your own features. * Can be used in both mod_perl and CGI environments A sample usage: #!/usr/bin/perl use strict; use warnings; use CGI; use WWW::Form; # Used by WWW::Form to perform various validations on user entered input use WWW::FieldValidator; # Define values for form input name attributes as constants use constant EMAIL_FIELD_NAME => 'emailAddress'; use constant PASSWORD_FIELD_NAME => 'password'; # Gets us access to the HTTP request data my $q = CGI->new(); # Hash ref of HTTP vars, would be $r->param() if you're using mod_perl my $params = $q->Vars() || {}; my $form = WWW::Form->new( get_form_fields(), $params, [&EMAIL_FIELD_NAME, &PASSWORD_FIELD_NAME] ); # Check to see that the form was submitted by the user if you're using # mod_perl, instead of $ENV{REQUEST_METHOD} you'd have $r->method() if ($form->is_submitted($ENV{REQUEST_METHOD})) { # Validate user entered data $form->validate_fields(); # If the data was good, do something if ($form->is_valid()) { # Do some stuff with params because we know the user entered data # passed all of its validation } } # Display the HTML web page print < A Simple HTML Form HTML # Display the HTML form content print $form->get_form_HTML(action => './'); print < HTML # Returns data structure suitable for passing to WWW::Form object # constructor, the keys will become the names of the HTML form inputs sub get_form_fields { my %fields = ( &EMAIL_FIELD_NAME => { label => 'Email address', defaultValue => '', type => 'text', validators => [WWW::FieldValidator->new( WWW::FieldValidator::WELL_FORMED_EMAIL, 'Make sure email address is well formed' )] }, &PASSWORD_FIELD_NAME => { label => 'Password', defaultValue => '', type => 'password', validators => [WWW::FieldValidator->new( WWW::FieldValidator::MIN_STR_LENGTH, 'Password must be at least 6 characters', 6 )] } ); return \%fields; } Creating WWW::Form Objects { # UI presentable value that will label the form input label => 'Your name', # If set, the form input will be pre-populated with this value # you could hard code a default value or use a value retrieved # from a data base table, for example defaultValue => 'Homer Simpson', # The type of form input, i.e. text, checkbox, textarea, etc. # (more on this later) type => 'text', # An array ref of various validations that should be performed on the # user entered input validators => [], # A hash ref that contains extra HTML attributes to add to the # container. container_attributes => {}, # A hint that will be displayed to the user near the control and its # label to guide him what to fill in that control. (optional) hint => 'text', # A hash ref that contains extra HTML attributes to add to the # container of the hint. hint_container_attributes => {}, } Supported Form Inputs The following form input types are supported by the WWW::Form module (these values should be used for the 'type' key of your $fieldsData->{$fieldName} hash ref): text password hidden file checkbox radio select textarea The following structure can be used for text, password, hidden, file, and textarea form inputs: $fieldName => { label => 'Your name', defaultValue => 'Homer Simpson', type => 'text', # or file, password, hidden, textarea validators => [] } The following structure should be used for radio and select form inputs: The data structure for input types radio and select use an array of hash references called optionsGroup. The optionsGroup label is what will be displayed in the select box or beside the radio button, and the optionsGroup value is the value that will be in the hash of HTTP params depending on what the user selects. To pre-select a select box option or radio button, set its defaultValue to a value that is found in the optionsGroup hash ref. For example, if you wanted the option 'Blue' to be selected by default in the example below, you would set defaultValue to 'blue'. $fieldName => { label => 'Favorite color', defaultValue => '', type => 'select', optionsGroup => [ {label => 'Green', value => 'green'}, {label => 'Red', value => 'red'}, {label => 'Blue', value => 'blue'} ], validators => [] } The following structure should be used for checkboxes: Note: All checkbox form inputs need a defaultValue to be specified, this is the value that will be used if the checkbox is checked when the form is submitted. If a checkbox is not checked then there will not be an entry for it in the hash of HTTP POST params. If defaultChecked is 1 the checkbox will be selected by default, if it is 0 it will not be selected by default. $fieldName => { label => 'Do you like spam?', defaultValue => 'Yes, I love it!', defaultChecked => 0, # 1 or 0 type => 'checkbox', validators => [] } FUNCTION REFERENCE NOTE: All methods are available using internalCapsStyle and underscore_separated_style. So 'isSubmitted' is also available as 'is_submitted', and 'getFieldHTMLRow' is also available as 'get_field_HTML_row', and so on and so forth. new Creates a WWW::Form object. $fieldsData is a hash reference that describes your WWW::Form object. (See instantiating a WWW::Form object above.) $fieldsValues (i.e., $params below) has keys identical to $fieldsData. $fieldsValues is a hash reference of HTTP POST variables. $fieldsOrder is an array reference of $fieldsData keys that is used to determine the order that form inputs are displayed in when getFormHTML() is called. If you don't use this parameter you should use the other public methods provided and display your form inputs by hand. Example: my $params = $r->param() || {}; my $form = WWW::Form->new($fieldsData, $params, $fieldsOrder); validateFields Validates field's values input according to the validators (WWW::FieldValidators) that were specified when the WWW::Form object was created. This will also set error feedback as necessary for form inputs that are not valid. Returns hash reference of all the fields that are valid (generally you don't need to use this for anything though because if all the validation passes you can just use your hash ref of HTTP $params, i.e. $r->param()). Example: if ($form->isSubmitted($r->method)) { # validate fields because form was POSTed $form->validateFields(); } getFields Returns hash ref of fields data. Example: my $fields = $form->getFields(); resetFields Resets values and default values for all fields Example: $form->resetFields(include_defaults => 1); getField Returns hash ref of field data that describes the form input that corresponds to the passed $fieldName ($fieldName should be a value of a key in the $fieldsData hash ref you used to construct your WWW::Form instance). Example: my $field = $form->getField('address'); getFieldErrorFeedback Returns an array of all the error feedback (if any) for the specified $fieldName. Example: my $name_feedback = $form->getFieldErrorFeedback('fullName'); getFieldsOrder Returns array ref of field names in the order that they will be displayed. Example: $form->getFieldsOrder(); getFieldValue Returns the current value of the specified $fieldName. Example: $form->getFieldValue('comments'); isFieldValid Returns 1 or 0 depending on whether or not the specified field name is valid. Example: $form->isFieldValid('zip_code'); getFieldValidators Returns array ref of validators for the passed field name. Example: $validators = $form->getFieldValidators($fieldName); getFieldType Returns value of a field's 'type' key for the specified $fieldName. Example: my $input_type = $form->getFieldType('favoriteColor'); getFieldLabel Returns the label associated with the specified $fieldName. Example: my $ui_label = $form->getFieldLabel('favoriteBand'); getFieldHint Returns the hint associated with the specified $fieldName or undef if it does not exist. Example: my $hint = $form->getFieldHint('favoriteBand'); setFieldValue Sets the value of the specified $fieldName to $value. You might use this if you need to convert a user entered value to some other value. Example: $form->setFieldValue('fullName', uc($form->getFieldValue('fullName'))); isValid Returns true if all form fields are valid or false otherwise. Example: if ($form->isSubmitted($r->method)) { # validate fields because form was POSTed $form->validateFields($params); # now check to see if form inputs are all valid if ($form->isValid()) { # do some stuff with $params because we know # the validation passed for all the form inputs } } isSubmitted Returns true if the HTTP request method is POST. If for some reason you're using GET to submit a form then this method won't be of much help. If you're not using POST as the method for submitting your form you may want to override this method in a subclass. Example: # Returns true if HTTP method is POST if ($form->isSubmitted($r->method())) { print "You submitted the form."; } asString Returns a string representation of the current instance. Example: &LOG->debug("WWW::Form instance: " . $form->asString()); getFieldFormInputHTML Returns an HTML form input for the specified $fieldName. $attributesString is an (optional) arbitrary string of HTML attribute key='value' pairs that you can use to add attributes to the form input, such as size='20' or onclick='someJSFunction()', and so forth. Example: $html .= $form->getFieldFormInputHTML( 'password', " size='6' class='PasswordInput' " ); getFieldHTMLRow Note: Need to make sure you can pass in attributesString param unnamed! $self->getFieldHTMLRow($fieldName, 'attributesString' => $attributesString, 'form_args' => \%form_args, ); Returns HTML to display in a web page. $fieldName is a key of the $fieldsData hash that was used to create a WWW::Form object. $attributesString is an (optional) arbitrary string of HTML attribute key='value' pairs that you can use to add attributes to the form input. %form_args are the parameters passed to the form as a whole, and this function will extract relevant parameters out of there. The only caveat for using this method is that it must be called between and
tags. It produces the following output: $errorFeedback $fieldLabel $fieldFormInput getFieldFeedbackHTML Returns HTML error content for each vaildator belonging to $fieldName that doesn't pass validation. Returns following HTML: Note: If you use this, you should implement a CSS class named 'feedback' that styles your error messages appropriately. Example: $html .= $form->getFieldFeedbackHTML('emailAddress'); startForm Returns an opening HTML form tag. Arguments: name - Value of HTML name attribute. action - Value of action HTML attribute. attributes - Optional hash ref of HTML attribute name value pairs. is_file_upload - Optional, boolean, should be true if your form contains file inputs. Example: $form->start_form( action => '/', name => 'MyFormName', attributes => {class => 'MyFormClass'} ); Returns HTML similar to:
endForm Returns HTML to close form. Example: $html .= $form->endForm(); getFormHTML Loops through the fieldsOrder array and builds markup for each form input in your form. Returns HTML markup that when output will display your form. Arguments: action - Value of form's action attribute. name - Value that will be used for form's name and id attribute. attributes - hashref of key value pairs that can be used to add arbitrary attributes to the opening form element. submit_label - Optional label for your form's submit button. submit_name - Optional Value of your submit button's name attribute. This value will also be used for your submit button's id attribute. submit_type - Optional string value, defaults to submit, if you want to use an image submit button pass submit_type as 'image'. submit_src - Optional unless submit_type is 'image' then an image src should be specified with submit_src, e.g. submit_src => './img/submit_button.png'. submit_class - Optional string that specifies a CSS class. submit_attributes - Optional hash ref of arbitrary name => 'value' HTML attributes. is_file_upload - Optional boolean that should be true if your form contains a file input. hint_container_attributes - Optional HTML attributes for all the table rows containing the hints. buttons - Use this if you want your form to have multiple submit buttons. See API documentation for getSubmitButtonHTML() for more info on this parameter. Example: print $form->getFormHTML( action => './', name => 'LoginForm', attributes => { class => 'FormBlueBackground' }, submit_label => 'Login', is_file_upload => 1 ); getSubmitButtonHTML Used by get_form_HTML to get HTML to display a type of a submit button. Returns string of HTML. Arguments: submit_type - 'submit' or 'image', defaults to 'submit' if not specified. submit_src - If type is 'image', this specifies the image to use. submit_label - Optional label for the button, defaults to 'Submit'. submit_class - Optional value for class attribute. submit_attributes - Optional hash ref of name => value pairs used to specify arbitrary attributes. buttons - Optional, array reference of hash refs of the previous arguments. You can use this parameter if you want your form to have multiple submit buttons. SEE ALSO WWW::FieldValidator To see some demos of WWW::Form and WWW::FieldValidator point your web browser to: or The following modules are related to WWW::Form and WWW::FieldValidator, you might want to check them out. Data::FormValidator Embperl::Form::Validate Rose::HTML::Form HTML::Form AUTHOR Ben Schmaus If you find this module useful or have any suggestions or comments please send me an email at CHANGELOG July 2, 2003 Code formatting and cleanup. Adds support for file inputs. July 3, 2003 Adds code examples to documentation for public methods. September 25, 2003 Adds new methods including: resetFields(), isFieldValid(), and getFieldValidators(). Changes _setFields method to handle empty user values. That is, in previous releases, if a form is submitted and the value for a field is empty, the value of the field will be set to the field's default value if it has one. This release updates _setFields to prefer submitted values over default values. Fixes some pdoc stuff. September 26, 2003 More pdoc changes. January 10, 2004 Adds support for displaying multiple submit buttons. Adds new public method: getSubmitButtonHTML. Adds support for escaping the value of HTML input 'value' attributes. January 5, 2005 Adds README file to distribution. Makes some minor documentation changes. TODO Add more helpful error logging. Add functionality for generating client side validation. Give this module a better namespace? Extension Idea Write a subclass that supports a templating library like Text::MicroMason or Text::Template. THANKS Thanks to Shlomi Fish for suggestions and code submissions. BUGS Nothing that I'm aware of, but please let me know if you have any problems. Send email to COPYRIGHT Copyright 2003, Ben Schmaus. All Rights Reserved. This program is free software. You may copy or redistribute it under the same terms as Perl itself.