Decorator limitations

While rewriting the Icinga Web login form to ipl forms I've encountered a limitation for decorators.

The html in the following code snippets is simplified for better readability.

Wanted

<div class="control-group remember-me-box">
    <input value="n" name="rememberme" type="hidden">
    <input value="y" name="rememberme" type="checkbox">
    <label class="toggle-switch">
        <span class="toggle-slider"></span>
    </label>
    <div class="control-label-group">
        <label class="form-element-label">Angemeldet bleiben</label>
    </div>
</div>

Expected PHP

This won't work, because the label group would wrap the label and the checkbox itself.

$this->addElement(
    'checkbox',
    'rememberme',
    [
        'label'         => $this->translate('Stay logged in'),
        'decorators'    => [
            'Checkbox' => new CheckboxDecorator(),
            'RenderElement' => new RenderElementDecorator(),
            'Label' => new LabelDecorator(),
            'LabelGroup' => [
                'name' => 'HtmlTag',
                'options' => ['tag' => 'div', 'class' => 'control-label-group']
            ],
            'ControlGroup' => [
                'name' => 'HtmlTag',
                'options' => ['tag' => 'div', 'class' => 'control-group remember-me-box']
            ],
        ]
    ]
);

This would result into this

<div class="control-group remember-me-box">
    <div class="control-label-group">
        <input value="n" name="rememberme" type="hidden">
        <input value="y" name="rememberme" type="checkbox">
        <label class="toggle-switch">
            <span class="toggle-slider"></span>
        </label>
        <label class="form-element-label">Angemeldet bleiben</label>
    </div>
</div>

Problem description

Because the transformation type wrap does wrap all previous elements it is not possible to add one or multiple standalone elements before a wrapped element.

No files, tests, or entry points are named. Start by tracing the decorator transformation type wrap and how it groups prior elements; done means decorators can place standalone elements before a wrapped element while producing the wanted checkbox markup without wrapping all previous elements.