FieldtypeRepeater

FieldsetPage (extends RepeaterPage, which extends Page). Always a single object — never a PageArray. The fieldset page is created automatically when the field is first used.

// Access fields on the fieldset page
echo $page->fieldset_field->title;
echo $page->fieldset_field->some_other_field;

// Set a field value
$page->fieldset_field->title = 'New value';
$page->save('fieldset_field');

// Check if a subfield is populated
if($page->fieldset_field->title) { ... }

// Access the owner page and field
$ownerPage  = $page->fieldset_field->getForPage();
$ownerField = $page->fieldset_field->getForField();
$ownerTitle = $page->fieldset_field->getForPage()->title;

// Always turn off output formatting when manipulating items
$page->of(false);

// Add a new item
$item = $page->repeater_field->getNewItem();
$item->title = 'New item';
$item->save();
$page->save('repeater_field'); // saves item order, count, and membership

// Remove an item
$page->repeater_field->remove($item);
$page->save('repeater_field');

// Reorder items: manipulate the RepeaterPageArray, then save the parent page
// The order of the array is what determines saved order.
$items = $page->repeater_field;

$itemA = $items->first();
$itemB = $items->last();
$items->append($itemA);                   // move first item to end
$items->prepend($itemB);                  // move last item to beginning
$items->insertBefore($itemA, $itemB);     // move $itemA to just before $itemB
$items->insertAfter($itemA, $itemB);      // move $itemA to just after $itemB
$items->reverse();                        // reverse the order of all items
$items->sort('title');                    // sort items by a sub-field value

$page->save('repeater_field'); // persists the new order

// Add multiple items, then save the parent page once at the end
$rows = [
    [ 'title' => 'First item',  'body' => '<p>Hello</p>' ],
    [ 'title' => 'Second item', 'body' => '<p>World</p>' ],
];
foreach($rows as $data) {
    $item = $page->repeater_field->getNewItem();
    foreach($data as $key => $value) $item->set($key, $value);
    $item->save();
}
$page->save('repeater_field');

Save workflow: $item->save() writes the item's field values to the database. $page->save('repeater_field') updates the parent page's field record (item order, count, and which items belong to it). Both calls are required when adding items; only $item->save() is needed for in-place edits to an existing item.

The non-obvious part is that a repeater field requires a dedicated template and fieldgroup to hold its sub-fields. Call _getRepeaterTemplate() after saving the field — it creates the template/fieldgroup automatically if they don't exist yet.

$fields    = $wire->fields;
$templates = $wire->templates;

// 1. Create and save the repeater field
/** @var RepeaterField $field */
$field = $fields->new('repeater', 'my_repeater', 'My Repeater');
// ------------------- ^Fieldtype --- ^Name -------- ^Label

// 2. Get/create the repeater's internal template and fieldgroup
$fieldgroup = $field->getRepeaterFieldgroup();

// 3. Add sub-fields to the repeater's fieldgroup
$fieldgroup->add('title');
$fieldgroup->add('body');
$fieldgroup->save();

// 4. Add the repeater field to your template
$template = $templates->get('your-template');
$template->fieldgroup->add($field);
$template->fieldgroup->save();

Notes on programmatic creation:

• $field->getRepeaterTemplate() creates and returns the repeater's internal template and fieldgroup if they don't exist yet, and stores template_id on the field. Always call this after creating the field.
• The repeater template is named repeater_{field_name} automatically.
• Sub-fields are added directly to $repeaterTemplate->fieldgroup — the fieldgroup membership IS the field list.
• $field->getRepeaterParent() returns the parent page under which repeater item pages are stored (e.g. /processwire/page/repeaters/for-field-123/).
• $field->getBlankRepeaterPage($page) returns a new unsaved repeater item page for the given owner page — useful when creating items without going through getNewItem().

Supports the same subfield selectors as FieldtypeRepeater:

$pages->find('fieldset_field.title*=keyword');
$pages->find('fieldset_field.some_field=value');

// Iterate and output
foreach($page->repeater_field as $item) {
    echo "<h3>{$item->headline}</h3>";
    echo "<p>{$item->body}</p>";
}

// Template syntax with each()
echo $page->repeater_field->each("<div><h3>{headline}</h3><p>{body}</p></div>");

// Depth-aware output (when repeaterDepth field setting is enabled)
foreach($page->repeater_field as $item) {
    $indent = str_repeat('  ', $item->depth);
    echo $indent . $item->title . "\n";
}

• The value is always a single FieldsetPage instance, never a PageArray.
• Fields on the fieldset page exist in their own namespace, so title on one fieldset is independent of title on another — even if both fieldsets use the same field.
• The fieldset page mirrors the output formatting (of()) state of its owner page automatically.
• Compatible fieldtypes: FieldtypeFieldsetPage only.