WP Form Class

<?php
/*
Settings Helper for WordPress
Copyright (C) 2011 William Barnes

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

/** WP Settings Form Helper
  *
  * Helper class for creating settings forms.
  */
if (!class_exists('WP_Settings_Form')):

class WP_Settings_Form
{
    /**
     * Configuration
     *
     * Public so that you can make adjustments.
     */
    public $config = array();
    protected $_errors = array();

    // CONFIG

    public function __construct($config)
    {
        $this->config = $config;
    }

    /**
     * Gets the option
     *
     * In simple mode: returns the row from wp_options that corresponds to the
     * option_name for the form.
     *
     * In multi mode: returns either the row from options array or if no key
     * then the defaults.
     *
     * The force argument causes it to return the entire array when in multi
     * mode.
     */
    public function get_option($force=false)
    {
        $config = $this->config;
        $option = get_option($config['option_name']);
        if (!is_array($option)):
            $option = array();
        endif;

        if ($force || !$this->is_multi()):
            return $option;

        // MULTI: Insert
        elseif ($this->get_request_type() == 'insert'):
            return isset($config['defaults']) ? $config['defaults'] : array();

        // MULTI: Edit
        else:
            return $option[$_REQUEST['_wpform_key']];
        endif;
    }

    // QUERY
    // Many of these are called only once, but this makes it easier to read the
    // code later.

    public function is_multi()
    {
        return isset($this->config['multi']);
    }

    public function is_form_submission()
    {
        return (isset($_POST['_wpform_option']) && ($_POST['_wpform_option'] == $this->config['option_name']));
    }

    public function get_request_type()
    {
        if (!$this->is_multi()):
            return 'edit'; // Always edit
        elseif (!isset($_REQUEST['_wpform_key']) || empty($_REQUEST['_wpform_key'])):
            return 'insert';
        elseif (is_numeric($_GET['_wpform_key'])):
            return 'edit';
        elseif (is_array($_POST['_wpform_key']) && isset($_REQUEST['_wpform_action']) && ($_POST['_wpform_action'] == 'delete')):
            return 'delete';
        elseif (is_array($_POST['_wpform_key']) && isset($_REQUEST['_wpform_action'])):
            // Custom action
            return  $_REQUEST['_wpform_action'];
        else:
            return null;
        endif;
    }

    public function is_single_form()
    {
        // Simple mode always shows the form.
        // Multi mode only shows it if we're editing or inserting a new item.
        // In multi, make sure that it's *this* form.
        return (
                    ( !$this->is_multi() ) ||
                    ( isset($_GET['_wpform_option']) && ($_GET['_wpform_option'] == $this->config['option_name']) )
                );
    }

    /**
     * Validate
     *
     * Provide it with a new option. It checks for variables based on the form
     * definition, validates them, and returns the validated option.
     *
     */
    public function validate($new_option_group)
    {
        $config = $this->config;
        $option = $this->get_option();

        // Loop through the form definition and process only defined variables
        $sections = $config['sections'];
        foreach ($sections as $section):
            $fields = $section['fields'];
            foreach ($fields as $field):

                // Check for field in submission
                if (array_key_exists($field['name'],$new_option_group)):
                    $name       = $field['name'];
                    $old_value  = isset($option[$name]) ? $option[$name] : null;
                    $test_value = $new_option_group[$name];

                    // User provided default validation
                    if (!isset($field['validator'])):
                        $option[$name] = call_user_func($config['validator'],$test_value,$old_value,$field);

                    // Use local validation
                    elseif (is_array($field['validator']) && array_key_exists('type',$field['validator'])):
                        $option[$name] = $this->validate_local($field['validator'],$test_value,$old_value,$field);

                    // No validation
                    elseif ($field['validator'] === false):
                        $option[$name] = $test_value;

                    // User provided field-specific validation
                    else:
                        $option[$name] = call_user_func($field['validator'],$test_value,$old_value,$field);
                    endif;
                endif;

            endforeach; // Fields
        endforeach; // Sections

        return $option;
    }

    /**
     * Validation shortcuts
     *
     * So users don't have to write their own.
     */
    public function validate_local($validator,$test_value,$old_value,$field)
    {
        if ((!isset($field['required']) || $field['required'] == false) && $test_value == ''): // Allow empty values
            return '';
        endif;

        switch($validator['type']):
            case "preg_replace":
                return preg_replace($validator['pattern'],$validator['replacement'],$test_value);

            case "preg_match":
                if (preg_match($validator['pattern'],$test_value)):
                    return $test_value;
                else:
                    $this->error($$field['label'] . ': incorrect format');
                    return $old_value;
                endif;

            case "url": // http://daringfireball.net/2010/07/improved_regex_for_matching_urls
                $re = "%^(?i)\b((?:https?://|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:'\".,<>?«»“”‘’]))$%";
                if (preg_match($re,$test_value)):
                    return $test_value;
                else:
                    $this->error($field['label'] . ': not a valid url');
                    return $old_value;
                endif;

            case "email": // http://www.regular-expressions.info/email.html
                $re = "/^(?i)[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/";
                if (preg_match($re,$test_value)):
                    return $test_value;
                else:
                    $this->error($field['label'] . ': not a valid email');
                    return $old_value;
                endif;

            case "numeric":
                if (is_numeric($test_value)):
                    return $test_value;
                else:
                    $this->error($field['label'] . ': must be a number');
                    return $old_value;
                endif;

            default:
                // If you get this error, there's something wrong with your $config
                $this->error($field['label'] . ': validation type does not exist.');
                return $old_value;
        endswitch;
    }

    /**
     * Register the form
     */
    public function register()
    {
        $config      = $this->config;
        $option_name = $config['option_name'];

        // Is this a form submission?
        if ($this->is_form_submission()):
            $option = $this->get_option(true);

            // Adding or editing
            if ($this->is_single_form() && check_admin_referer('_wpform_single','_wpform_nonce')):
                $key        = isset($_POST['_wpform_key']) ? $_POST['_wpform_key'] : '';
                $new_option = $this->validate( $_POST[$option_name] );

                // Do nothing if there were validation errors
                if (empty($this->_errors)):

                    // MULTI MODE: Adding
                    if ($this->get_request_type() == 'insert'):
                        // Defaults
                        if (array_key_exists('defaults',$config)):
                            $new_option += $config['defaults'];
                        endif;

                        // Add new item to end of array
                        $key          = time(); // Use a timestamp so keys are always unique
                        $option[$key] = $new_option;

                        // Forward to the edit page for the item just added
                        $redirect = add_query_arg(array(
                            '_wpform_key'=>$key,
                            '_wpform_success' => $config['option_name'],
                            '_wpform_error'=>false
                        ));

                    // MULTI MODE: Editing
                    elseif ($this->is_multi() && ($this->get_request_type() == 'edit')):
                        if (array_key_exists($key,$option)):
                            $option[$key] = $new_option;

                            // Return to the edit page
                            $redirect = add_query_arg(array(
                                '_wpform_success' => $config['option_name'],
                                '_wpform_error'=>false
                            ));

                        // Somebody requested a key that doesn't exist, do nothing
                        else:
                            $this->error('Key does not exist');
                        endif;

                    // SIMPLE MODE: Editing
                    else:
                        $option = $new_option;

                        // Back to edit page (index)
                        $redirect = add_query_arg(array(
                            '_wpform_success' => $config['option_name'],
                            '_wpform_error'=>false
                        ));
                    endif;
                endif;

            // MULTI MODE ONLY: Deleting or other
            elseif ($this->get_request_type() && check_admin_referer('_wpform_multi','_wpform_nonce')):
                $keys   = $_POST['_wpform_key'];
                $action = $this->get_request_type();

                // Delete
                if ($action == 'delete'):
                    foreach($keys as $key):
                        if (array_key_exists($key,$option)) unset($option[$key]);
                    endforeach;

                    // Back to index
                    $redirect = add_query_arg(array(
                        '_wpform_success' => $config['option_name'],
                        '_wpform_error'=>false
                    ));

                // Custom action
                // Loop through the provided keys and call the user-provided function on each row
                else:
                    $buttons = isset($config['multi']['table_buttons']) ? $config['multi']['table_buttons'] : array();
                    if (array_key_exists($action, $buttons)):
                        foreach($keys as $key):
                            if (array_key_exists($key, $option) && isset($buttons[$action]['callback'])):
                                $option[$key] = call_user_func($buttons[$action]['callback'], $option[$key], &$this);
                            endif;
                        endforeach;

                        // Back to index
                        $redirect = add_query_arg(array(
                            '_wpform_success' => $config['option_name'],
                            '_wpform_error' => false
                        ));

                    else:
                        $this->error('Action does not exist');
                    endif;
                endif;

            // Something weird happened
            else:
                $this->error('Malformed request');
            endif;

            // Save changes to database
            if (empty($this->_errors)):
                update_option($config['option_name'],$option);

            // Print errors
            else:
                $message = '';
                foreach($this->_errors as $error):
                    $message .= '<li>' . $error . '</li>';
                endforeach;
                $redirect = add_query_arg(array(
                    '_wpform_error'=>urlencode($message),
                    '_wpform_success'=>false,
                ));
            endif;

            wp_redirect($redirect);
            exit;
        endif;
    }

    public function error($message)
    {
        $this->_errors[] = $message;
    }

    /**
     * Echos a form field
     *
     * TODO: Define more field types
     * You can add field types yourself, it's not too hard
     */
    public function echo_field($field)
    {
        $config = $this->config;
        $option = $this->get_option();

        // Attribute values
        $option_name = $config['option_name'];
        $field_name  = $field['name'];
        $field_id    = $config['option_name'].'_'.$field['name'];
        $field_value = isset($option[$field['name']]) ? $option[$field['name']] : '';
        $field_size  = isset($field['size']) ? $field['size'] : '40';

        switch ($field['type']):
            // Category Dropdown
            case "authors":
                wp_dropdown_users("id={$field_id}&name={$option_name}[{$field_name}]&selected={$field_value}");
                break;

            // Boolean (checkbox, value=1)
            case "boolean":
                echo "<input id='{$field_id}' name='{$option_name}[{$field_name}]' size='{$field_size}' type='checkbox' value='1'". (($field_value == 1) ? " checked='yes'" : '') ."' />";
                break;

            // Category Dropdown
            case "categories":
                wp_dropdown_categories("id={$field_id}&name={$option_name}[{$field_name}]&selected={$field_value}");
                break;

            // Dropdown
            case "dropdown":
                echo "<select id='{$field_id}' name='{$option_name}[{$field_name}]' />";
                foreach ($field['options'] as $key=>$value):
                    echo "<option value='{$key}'".($value == $field_value ? "selected='selected'" : "").">{$value}</option>";
                endforeach;
                echo "</select>";
                break;

            // Password
            case "password":
                echo "<input id='{$field_id}' name='{$option_name}[{$field_name}]' size='{$field_size}' type='password' value='{$field_value}' />";
                break;

            // Text field
            case "text":
            default:
                echo "<input id='{$field_id}' name='{$option_name}[{$field_name}]' size='{$field_size}' type='text' value='{$field_value}' />";
                break;
        endswitch;

        // Description (if present)
        if (isset($field['description'])) echo '<br />'.$field['description'];
    }

    public function echo_settings_page()
    {
        $config = $this->config;

        if ($this->is_single_form()):
            $this->echo_single_form();
        else:
            $this->echo_multi_index();
        endif;
    }

    /**
     * Echo form
     *
     * Call this within the HTML of your settings page function.
     */
    public function echo_single_form()
    {
        $config = $this->config;
?>
        <form action="<?php echo add_query_arg(array('_wpform_success'=>false,'_wpform_error'=>false)); ?>" method="post">
            <div class="inner">
                <?php if (isset($_REQUEST['_wpform_error'])): ?>
                    <div class="error">
                        <ul>
                            <?php echo $_REQUEST['_wpform_error']; ?>
                        </ul>
                    </div>
                <?php elseif (isset($_REQUEST['_wpform_success']) && ($_REQUEST['_wpform_success'] == $config['option_name'])): ?>
                    <div class="updated">
                        <p>Update successful.</p>
                    </div>
<?php
                endif;
                $sections = $config['sections'];
                foreach ($sections as $section):
?>
                    <h3><?php echo $section['title']; ?></h3>
                    <table class="form-table">
                        <tbody>
<?php
                            $fields = $section['fields'];
                            foreach ($fields as $field):
                                $field_id = $config['option_name'].'_'.$field['name'];
?>
                                <tr valign="top">
                                    <th scope="row"><label for="<?php echo $field_id; ?>"><?php echo $field['label']; ?></label></th>
                                    <td>
                                        <?php $this->echo_field($field); ?>
                                    </td>
                                </tr>
                            <?php endforeach; ?>
                        </tbody>
                    </table>
                <?php endforeach; ?>
<?php
                if (array_key_exists('hidden',$config)):
                    foreach ($config['hidden'] as $input):
                        echo "<input type='hidden' name='{$input['name']}' value='{$input['value']}' />";
                    endforeach;
                endif;

                if (isset($config['multi'])):
?>
                    <input type="hidden" name="_wpform_key" value="<?php echo isset($_REQUEST['_wpform_key']) ? $_REQUEST['_wpform_key'] : ''; ?>" />
<?php
                endif;
?>
                <input type="hidden" name="_wpform_option" value="<?php echo $config['option_name']; ?>" />
                <?php wp_nonce_field( '_wpform_single', '_wpform_nonce', true); ?>
                <p class="submit">
                    <input name="Submit" class="button-primary" type="submit" value="Save Changes" />
                </p>
            </div>
        </form>
<?php
    }

    /**
     * Echo table
     *
     * Prints a table of the items in a multi-dimensional option.
     */
    public function echo_multi_index()
    {
        $config = $this->config;
        $fields = $config['multi']['table_fields'];
?>
        <form action="<?php echo add_query_arg(array('_wpform_success'=>false,'_wpform_error'=>false)); ?>" method="post">
            <?php if (isset($_REQUEST['_wpform_error'])): ?>
                <div class="error">
                    <ul>
                        <?php echo $_REQUEST['_wpform_error']; ?>
                    </ul>
                </div>
            <?php elseif (isset($_REQUEST['_wpform_success']) && ($_REQUEST['_wpform_success'] == $config['option_name'])): ?>
                <div class="update">
                    <p>Update successful.</p>
                </div>
            <?php endif; ?>
            <?php if (isset($config['multi']['list_title'])): ?>
                <h3><?php echo $config['multi']['list_title']; ?></h3>
            <?php endif; ?>
            <table class="widefat">
                <colgroup>
                    <col style="width:20px;"/>
                    <col style="width:40px;"/>
<?php

                    foreach($fields as $field):
                        echo '<col' . (isset($field['width']) ? ' style="width:' . $field['width'] . '"' : '') . " />";
                    endforeach;
?>
                </colgroup>
                <thead><tr>
                    <th scope="col" class="check-column"><input type="checkbox" /></th>
                    <th scope="col">ID</th>
<?php
                    foreach($fields as $field):
                        echo '<th scope="col">' . $field['label'] . '</th>';
                    endforeach;
?>
                </tr></thead>
                <tbody>
<?php
                    $rows = $this->get_option(true);
                    foreach ($rows as $id=>$row):
?>
                        <tr>
                            <th class="check-column" scope="row"><input type="checkbox" value="<?php echo $id; ?>" name="_wpform_key[]" /></th>
                            <td><?php echo $id; ?></td>
<?php
                            foreach($fields as $field):
                                $type = isset($field['type']) ? $field['type'] : 'text';
                                $content = isset($row[$field['name']]) ? $row[$field['name']] : null;
                                switch ($type):
                                    case "date":
                                        $content = date('D, M j, Y',strtotime($content));
                                        break;
                                    case "datetime":
                                        $content = date('D, M j, Y H:i:s e',strtotime($content));
                                        break;
                                    case "timestamp":
                                        $content = date('D, M j, Y H:i:s e',$content);
                                        break;
                                    default:
                                        $content = (!empty($content) || ($content === 0) ? $content : '&nbsp;');
                                        break;
                                endswitch;

                                if (array_key_exists('link',$field) && $field['link']):
                                    echo '<td><a href="'.add_query_arg(array('_wpform_option'=>$config['option_name'],'_wpform_key'=>$id,'_wpform_success'=>false,'_wpform_error'=>false)).'">'.$content.'</a></td>';
                                else:
                                    echo "<td>$content</td>";
                                endif;
                            endforeach;
?>
                        </tr>
                    <?php endforeach; ?>
                </tbody>
            </table>
            <input type="hidden" name="_wpform_option" value="<?php echo $config['option_name']; ?>" />
            <?php wp_nonce_field( '_wpform_multi', '_wpform_nonce', true); ?>
            <div class="tablenav">
                <div class="alignleft">
<?php
                    $buttons = isset($config['multi']['table_buttons']) ? $config['multi']['table_buttons'] : array();
                    foreach ($buttons as $id=>$button):
                        echo '<button type="submit" name="'. (isset($button['name']) ? $button['name'] : '_wpform_action') .'" value="'. (isset($button['value']) ? $button['value'] : $id) .'" class="button-'. (isset($button['priority']) ? $button['priority'] : 'secondary') .'">'. $button['label'] .'</button> ';
                    endforeach;
?>
                    <button type="submit" name="_wpform_action" value="delete" class="button-secondary delete"><?php _e('Delete'); ?></button>
                </div>
                <br class="clear" />
            </div>
        </form>
        <form action="<?php echo add_query_arg(array('_wpform_success'=>false,'_wpform_error'=>false)); ?>" method="GET">
            <div class="inner">
<?php
                if (isset($config['multi']['new_fields'])):
?>
                    <h3><?php echo $config['multi']['new_title'] ?></h3>
                    <table class="form-table">
                        <tbody>
<?php
                            $fields = $config['multi']['new_fields'];
                            foreach ($fields as $field):
                                $field_id = $config['option_name'].'_'.$field['name'];
?>
                                <tr valign="top">
                                    <th scope="row"><label for="<?php echo $field_id; ?>"><?php echo $field['label']; ?></label></th>
                                    <td><?php $this->echo_field($field); ?></td>
                                </tr>
                            <?php endforeach; ?>
                        </tbody>
                    </table>
<?php
                endif;
?>
                <input type="hidden" name="_wpform_option" value="<?php echo $config['option_name']; ?>" />
                <input type="hidden" name="page" value="<?php echo $_GET['page']; ?>" />
                <p class="submit"><input class="button-primary" type="submit" value="<?php echo $config['multi']['new_title'] ?>" /></p>
            </div>
        </form>
<?php
    }
}

endif; // class_exists
?>