Let parents register once and book for their children

A parent registers once and manages lessons for one or more children, who
need no login of their own. A child is a real wp_users row with the student
role but no usable login — so student_id keeps meaning "a WordPress user"
on every table, and booking, credits, policies and enrolments work unchanged.
A us_guardians link table maps guardian to child.

The signup form gains a parent/guardian tick that reveals a block per child,
with the account-signup questions asked per child rather than per guardian
— they describe the student, not the account holder. Signup policies are
recorded once per child with the guardian as the acceptor, which is the
record that actually means something. A family that half-creates is rolled
back entirely rather than leaving a guardian who cannot re-register.

The booking and enrolment forms gain a "Who is this for?" picker listing
children first, so the default selection is never the parent — booking for
the wrong child is correctable, quietly billing a parent for their kid's
lesson is not. POST /bookings and POST /enrollments take an optional
student_id honoured only for that child's guardian; anything else is a 403.
That check is the authorisation boundary of the feature.

Payments and credits gain a payer: the charge names the child it was for and
the guardian who owes it, so per-child reporting is unchanged while notices,
receipts and the payment step reach the parent. Credit is held by the payer,
so one child's cancellation can settle a sibling's charge, and the daily
billing scan sends a guardian one notice covering every child.

Closes #132

Co-Authored-By: Claude Opus 5 <[email protected]>

templates/frontend/booking-page.php

@@ -9,8 +9,14 @@ if (! defined('ABSPATH')) {
 /** @var bool $showTypeFilter Whether the "Show Only" lesson-type filter is offered. */
 /** @var bool $showBooking Whether the booking calendar is part of this embed. */
 /** @var bool $showUpcoming Whether the student's upcoming-lessons panel is part of this embed. */
+/** @var list<array{id: int, name: string, is_self: bool}> $students Who this account may book for — children first, the account holder last. */
+
+// The booking script reads the list as JSON rather than rendering a <select>
+// here: the picker belongs inside the booking form it builds, and it is the same
+// list the group-classes script needs.
+$studentsJson = wp_json_encode(array_values($students));
 ?>
-<div id="us-booking-app" data-nonce="<?php echo esc_attr(wp_create_nonce('wp_rest')); ?>"<?php echo $lessonTypeId > 0 ? ' data-lesson-type="' . esc_attr((string) $lessonTypeId) . '"' : ''; ?><?php echo $showTypeFilter ? '' : ' data-type-filter="0"'; ?>>
+<div id="us-booking-app" data-nonce="<?php echo esc_attr(wp_create_nonce('wp_rest')); ?>" data-students="<?php echo esc_attr(is_string($studentsJson) ? $studentsJson : '[]'); ?>"<?php echo $lessonTypeId > 0 ? ' data-lesson-type="' . esc_attr((string) $lessonTypeId) . '"' : ''; ?><?php echo $showTypeFilter ? '' : ' data-type-filter="0"'; ?>>
     <?php if ($showUpcoming) : ?>
     <div id="us-my-lessons"></div>
     <?php endif; ?>

templates/frontend/family-page.php

@@ -0,0 +1,107 @@
+<?php
+declare(strict_types=1);
+
+use Unsupervised\Schedular\Registration\QuestionField;
+
+if (! defined('ABSPATH')) {
+    exit;
+}
+
+/**
+ * @var list<array{id: int, name: string, date_of_birth: string, relationship: string}> $children
+ * @var list<\Unsupervised\Schedular\Registration\Question> $questions Account-scope questions, asked once per child.
+ * @var string $error  Validation error from the last submission, if any.
+ * @var string $notice Confirmation of a completed add/edit/remove, if any.
+ * @var int    $editingId Child whose row is open for editing; 0 for none.
+ */
+?>
+<div class="us-family">
+    <h3><?php esc_html_e('Your family', 'unsupervised-schedular'); ?></h3>
+
+    <?php if ($notice !== '') : ?>
+        <p class="us-success"><?php echo esc_html($notice); ?></p>
+    <?php endif; ?>
+
+    <?php if ($error !== '') : ?>
+        <p class="us-error" role="alert"><?php echo esc_html($error); ?></p>
+    <?php endif; ?>
+
+    <?php if (empty($children)) : ?>
+        <p><?php esc_html_e('You have not added any children yet. Add one below to start booking lessons for them.', 'unsupervised-schedular'); ?></p>
+    <?php else : ?>
+        <ul class="us-family-list">
+            <?php foreach ($children as $child) : ?>
+                <li class="us-family-child">
+                    <?php if ($editingId === $child['id']) : ?>
+                        <form method="post" action="" class="us-family-edit">
+                            <?php wp_nonce_field('us_family'); ?>
+                            <input type="hidden" name="us_family_action" value="edit">
+                            <input type="hidden" name="child_id" value="<?php echo esc_attr((string) $child['id']); ?>">
+                            <p>
+                                <label for="us-edit-name-<?php echo esc_attr((string) $child['id']); ?>"><?php esc_html_e('Name', 'unsupervised-schedular'); ?></label>
+                                <input type="text" name="child_name" id="us-edit-name-<?php echo esc_attr((string) $child['id']); ?>" value="<?php echo esc_attr($child['name']); ?>" required>
+                            </p>
+                            <p>
+                                <label for="us-edit-dob-<?php echo esc_attr((string) $child['id']); ?>"><?php esc_html_e('Date of birth', 'unsupervised-schedular'); ?></label>
+                                <input type="date" name="child_dob" id="us-edit-dob-<?php echo esc_attr((string) $child['id']); ?>" value="<?php echo esc_attr($child['date_of_birth']); ?>">
+                            </p>
+                            <p>
+                                <button type="submit"><?php esc_html_e('Save', 'unsupervised-schedular'); ?></button>
+                                <a href="<?php echo esc_url((string) get_permalink()); ?>"><?php esc_html_e('Cancel', 'unsupervised-schedular'); ?></a>
+                            </p>
+                        </form>
+                    <?php else : ?>
+                        <span class="us-family-child-name"><?php echo esc_html($child['name']); ?></span>
+                        <?php if ($child['date_of_birth'] !== '') : ?>
+                            <span class="us-family-child-dob"><?php echo esc_html($child['date_of_birth']); ?></span>
+                        <?php endif; ?>
+                        <span class="us-family-child-actions">
+                            <a href="<?php echo esc_url(add_query_arg('us_edit_child', $child['id'], (string) get_permalink())); ?>"><?php esc_html_e('Edit', 'unsupervised-schedular'); ?></a>
+                            <form method="post" action="" class="us-family-remove">
+                                <?php wp_nonce_field('us_family'); ?>
+                                <input type="hidden" name="us_family_action" value="remove">
+                                <input type="hidden" name="child_id" value="<?php echo esc_attr((string) $child['id']); ?>">
+                                <button type="submit"><?php esc_html_e('Remove', 'unsupervised-schedular'); ?></button>
+                            </form>
+                        </span>
+                    <?php endif; ?>
+                </li>
+            <?php endforeach; ?>
+        </ul>
+    <?php endif; ?>
+
+    <form method="post" action="" class="us-family-add">
+        <?php wp_nonce_field('us_family'); ?>
+        <input type="hidden" name="us_family_action" value="add">
+
+        <h4><?php esc_html_e('Add a child', 'unsupervised-schedular'); ?></h4>
+        <p>
+            <label for="us-child-name"><?php esc_html_e('Name', 'unsupervised-schedular'); ?></label>
+            <input type="text" name="child_name" id="us-child-name" required>
+        </p>
+        <p>
+            <label for="us-child-dob"><?php esc_html_e('Date of birth', 'unsupervised-schedular'); ?></label>
+            <input type="date" name="child_dob" id="us-child-dob">
+        </p>
+        <p>
+            <label for="us-child-relationship"><?php esc_html_e('Your relationship to them', 'unsupervised-schedular'); ?></label>
+            <input type="text" name="child_relationship" id="us-child-relationship" placeholder="<?php esc_attr_e('Parent', 'unsupervised-schedular'); ?>">
+        </p>
+
+        <?php if (! empty($questions)) : ?>
+            <fieldset class="us-reg-questions">
+                <legend><?php esc_html_e('About this child', 'unsupervised-schedular'); ?></legend>
+                <?php foreach ($questions as $question) : ?>
+                    <?php
+                    // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- QuestionField::render() escapes every interpolated value.
+                    echo QuestionField::render($question, 'us_answers[' . (int) $question->id . ']', 'us-family-q-' . (int) $question->id);
+                    ?>
+                <?php endforeach; ?>
+            </fieldset>
+        <?php endif; ?>
+
+        <p>
+            <button type="submit"><?php esc_html_e('Add child', 'unsupervised-schedular'); ?></button>
+        </p>
+    </form>
+</div>

templates/frontend/group-classes-page.php

@@ -6,8 +6,13 @@ if (! defined('ABSPATH')) {
 }
 
 /** @var int $offeringId Offering id when the page is restricted to a single class; 0 for the full catalog. */
+/** @var list<array{id: int, name: string, is_self: bool}> $students Who this account may enrol — children first, the account holder last. */
+
+// The enrolment script reads the list as JSON, so the picker can be built inside
+// the enrolment form it renders.
+$studentsJson = wp_json_encode(array_values($students));
 ?>
-<div id="us-group-app"<?php echo $offeringId > 0 ? ' data-offering="' . esc_attr((string) $offeringId) . '"' : ''; ?>>
+<div id="us-group-app" data-students="<?php echo esc_attr(is_string($studentsJson) ? $studentsJson : '[]'); ?>"<?php echo $offeringId > 0 ? ' data-offering="' . esc_attr((string) $offeringId) . '"' : ''; ?>>
     <div id="us-group-list">
         <p><?php esc_html_e('Loading group classes…', 'unsupervised-schedular'); ?></p>
     </div>

templates/frontend/register-page.php

@@ -2,6 +2,7 @@
 declare(strict_types=1);
 
 use Unsupervised\Schedular\Registration\Question;
+use Unsupervised\Schedular\Registration\QuestionField;
 
 if (! defined('ABSPATH')) {
     exit;
@@ -22,39 +23,6 @@ if (! defined('ABSPATH')) {
  * @var list<Question> $accountQuestions Studio-wide questions answered as step two.
  */
 
-/**
- * Render one account-signup question's input, named `us_answers[<id>]`.
- */
-$renderQuestionField = static function (Question $question): void {
-    $id       = (int) $question->id;
-    $name     = 'us_answers[' . $id . ']';
-    $fieldId  = 'us-reg-q-' . $id;
-    $required = $question->isRequired ? ' required' : '';
-    ?>
-    <p>
-        <label for="<?php echo esc_attr($fieldId); ?>">
-            <?php echo esc_html($question->label); ?>
-            <?php if ($question->isRequired) : ?>
-                <span class="us-required" aria-hidden="true">*</span>
-            <?php endif; ?>
-        </label>
-        <?php if ($question->fieldType === Question::FIELD_TEXTAREA) : ?>
-            <textarea name="<?php echo esc_attr($name); ?>" id="<?php echo esc_attr($fieldId); ?>" rows="4"<?php echo $required; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- literal attribute string. ?>></textarea>
-        <?php elseif ($question->fieldType === Question::FIELD_SELECT) : ?>
-            <select name="<?php echo esc_attr($name); ?>" id="<?php echo esc_attr($fieldId); ?>"<?php echo $required; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- literal attribute string. ?>>
-                <option value=""><?php esc_html_e('— Select —', 'unsupervised-schedular'); ?></option>
-                <?php foreach ((array) $question->options as $option) : ?>
-                    <option value="<?php echo esc_attr((string) $option); ?>"><?php echo esc_html((string) $option); ?></option>
-                <?php endforeach; ?>
-            </select>
-        <?php elseif ($question->fieldType === Question::FIELD_CHECKBOX) : ?>
-            <input type="checkbox" name="<?php echo esc_attr($name); ?>" id="<?php echo esc_attr($fieldId); ?>" value="1"<?php echo $required; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- literal attribute string. ?>>
-        <?php else : ?>
-            <input type="text" name="<?php echo esc_attr($name); ?>" id="<?php echo esc_attr($fieldId); ?>"<?php echo $required; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- literal attribute string. ?>>
-        <?php endif; ?>
-    </p>
-    <?php
-};
 ?>
 <div class="us-register-form">
     <?php if ($successType === 'confirm') : ?>
@@ -102,6 +70,48 @@ $renderQuestionField = static function (Question $question): void {
                         <input type="password" name="password" id="us-reg-pass" autocomplete="new-password" minlength="8" required>
                     </p>
 
+                    <fieldset class="us-guardian">
+                        <legend><?php esc_html_e('Who are you registering?', 'unsupervised-schedular'); ?></legend>
+                        <p>
+                            <label>
+                                <input type="checkbox" name="us_is_guardian" id="us-is-guardian" value="1">
+                                <?php esc_html_e("I'm registering as a parent or guardian, for one or more children", 'unsupervised-schedular'); ?>
+                            </label>
+                        </p>
+
+                        <?php /* Revealed by the checkbox; without JS it is simply always visible. */ ?>
+                        <div class="us-children" id="us-children">
+                            <p class="us-children-intro"><?php esc_html_e('Add each child you will be booking lessons for. They do not need their own login — you book and pay for them from this account.', 'unsupervised-schedular'); ?></p>
+
+                            <?php /* The first block is the template the "Add another child" button clones. */ ?>
+                            <div class="us-child" data-child-index="0">
+                                <p>
+                                    <label for="us-child-0-name"><?php esc_html_e("Child's name", 'unsupervised-schedular'); ?></label>
+                                    <input type="text" name="children[0][name]" id="us-child-0-name">
+                                </p>
+                                <p>
+                                    <label for="us-child-0-dob"><?php esc_html_e('Date of birth', 'unsupervised-schedular'); ?></label>
+                                    <input type="date" name="children[0][dob]" id="us-child-0-dob">
+                                </p>
+                                <?php foreach ($accountQuestions as $question) : ?>
+                                    <?php
+                                    // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- QuestionField::render() escapes every interpolated value.
+                                    echo QuestionField::render(
+                                        $question,
+                                        'children[0][answers][' . (int) $question->id . ']',
+                                        'us-child-0-q-' . (int) $question->id,
+                                        enforceRequired: false
+                                    );
+                                    ?>
+                                <?php endforeach; ?>
+                            </div>
+
+                            <p>
+                                <button type="button" class="us-add-child"><?php esc_html_e('Add another child', 'unsupervised-schedular'); ?></button>
+                            </p>
+                        </div>
+                    </fieldset>
+
                     <?php if (! empty($policyForms)) : ?>
                         <fieldset class="us-policies">
                             <legend><?php esc_html_e('Policies', 'unsupervised-schedular'); ?></legend>
@@ -124,6 +134,17 @@ $renderQuestionField = static function (Question $question): void {
                     <?php if ($hasQuestions) : ?>
                         <p>
                             <button type="button" class="us-reg-next"><?php esc_html_e('Next', 'unsupervised-schedular'); ?></button>
+                            <?php
+                            /*
+                             * In parent/guardian mode the questions are asked per child,
+                             * up in the children section, so step two has nothing left to
+                             * ask and "Next" leads nowhere. This submit takes its place —
+                             * hidden until the guardian box is ticked (and never shown at
+                             * all without JS, where both steps are visible anyway and the
+                             * step-two submit does the job).
+                             */
+                            ?>
+                            <input type="submit" name="us_register" class="us-reg-submit-early" hidden value="<?php esc_attr_e('Create Account', 'unsupervised-schedular'); ?>">
                         </p>
                     <?php else : ?>
                         <p>
@@ -137,7 +158,10 @@ $renderQuestionField = static function (Question $question): void {
                         <fieldset class="us-reg-questions">
                             <legend><?php esc_html_e('Registration information', 'unsupervised-schedular'); ?></legend>
                             <?php foreach ($accountQuestions as $question) : ?>
-                                <?php $renderQuestionField($question); ?>
+                                <?php
+                                // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- QuestionField::render() escapes every interpolated value.
+                                echo QuestionField::render($question, 'us_answers[' . (int) $question->id . ']', 'us-reg-q-' . (int) $question->id);
+                                ?>
                             <?php endforeach; ?>
                         </fieldset>
                         <p>