Brainstorming for ZF2 view layer

ViewLayerIdeas.php

<?php

// The default strategy would add a listener to Application::dispatch() at high 
// priority. This would inject a ViewModel instance with the layout template set
// as the template, no capture_to value, and a false terminal flag.

// The default strategy would also listen to Dispatchable::dispatch() at low 
// priority; a returned ViewModel instance would be injected into the MvcEvent
// as the ViewModel. At this time, we'd also check for a template on the 
// ViewModel, and if none found, auto-determine it and inject it based on the
// RouteMatch.

// Returning a feed
$viewModel = new ViewModel($varsToSet);
$viewModel->setTemplate('blog/feed')
          ->setTerminal(true);

// Setting an alternate capture point
$viewModel = new ViewModel($varsToSet);
$viewModel->setTemplate('sidebar/news')
          ->captureTo('sidebar');

// ... and then injecting this as a child
$parent = new ViewModel($mainVars);
$parent->addChild($viewModel);

// An event on Dispatchable::dispatch could mark the model as terminal -- e.g., 
// if an XHR request came through
if ($request->isXmlHttpRequest()) {
    $model = $e->getViewModel();
    if (0 == count($model)) {
        // Set as terminal and return
        $model->setTerminal(true);
        return; 
    }
    if (count($model) > 1) {
        throw new Exception('Inconsistent state; can't have multiple view models with XHR');
    }
    $child = false;
    foreach ($model as $child) {
        // Grab the first child
        break;
    }
    // Set child as terminal, and replace event's view model with child
    $child->setTerminal(true);
    $e->setViewModel($child);
}

// rendering loop...
if ($model->hasChildren()) { // could be 0 < count($model) ?
    foreach ($model as $child) {
        if ($model->isTerminal()) {
            throw new Exception('Terminal child; inconsistent state');
        }
        $result = render($child);
        $captureTo = $child->captureTo();
        if (!empty($captureTo)) {
            $model->setVariable($captureTo, $result);
        }
    }
}
$result = render($model);
// do something with result... inject to response, trigger event, ??