annotate core/lib/Drupal/Core/Render/RenderContext.php @ 19:fa3358dc1485 tip

Add ndrum files
author Chris Cannam
date Wed, 28 Aug 2019 13:14:47 +0100
parents 4c8ae668cc8c
children
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Chris@0 1 <?php
Chris@0 2
Chris@0 3 namespace Drupal\Core\Render;
Chris@0 4
Chris@0 5 /**
Chris@0 6 * The render context: a stack containing bubbleable rendering metadata.
Chris@0 7 *
Chris@0 8 * A stack of \Drupal\Core\Render\BubbleableMetadata objects.
Chris@0 9 *
Chris@0 10 * @see \Drupal\Core\Render\RendererInterface
Chris@0 11 * @see \Drupal\Core\Render\Renderer
Chris@0 12 * @see \Drupal\Core\Render\BubbleableMetadata
Chris@0 13 */
Chris@0 14 class RenderContext extends \SplStack {
Chris@0 15
Chris@0 16 /**
Chris@0 17 * Updates the current frame of the stack.
Chris@0 18 *
Chris@0 19 * @param array &$element
Chris@0 20 * The element of the render array that has just been rendered. The stack
Chris@0 21 * frame for this element will be updated with the bubbleable rendering
Chris@0 22 * metadata of this element.
Chris@0 23 */
Chris@0 24 public function update(&$element) {
Chris@0 25 // The latest frame represents the bubbleable metadata for the subtree.
Chris@0 26 $frame = $this->pop();
Chris@0 27 // Update the frame, but also update the current element, to ensure it
Chris@0 28 // contains up-to-date information in case it gets render cached.
Chris@0 29 $updated_frame = BubbleableMetadata::createFromRenderArray($element)->merge($frame);
Chris@0 30 $updated_frame->applyTo($element);
Chris@0 31 $this->push($updated_frame);
Chris@0 32 }
Chris@0 33
Chris@0 34 /**
Chris@0 35 * Bubbles the stack.
Chris@0 36 *
Chris@0 37 * Whenever another level in the render array has been rendered, the stack
Chris@0 38 * must be bubbled, to merge its rendering metadata with that of the parent
Chris@0 39 * element.
Chris@0 40 */
Chris@0 41 public function bubble() {
Chris@0 42 // If there's only one frame on the stack, then this is the root call, and
Chris@0 43 // we can't bubble up further. ::renderRoot() will reset the stack, but we
Chris@0 44 // must not reset it here to allow users of ::executeInRenderContext() to
Chris@0 45 // access the stack directly.
Chris@0 46 if ($this->count() === 1) {
Chris@0 47 return;
Chris@0 48 }
Chris@0 49
Chris@0 50 // Merge the current and the parent stack frame.
Chris@0 51 $current = $this->pop();
Chris@0 52 $parent = $this->pop();
Chris@0 53 $this->push($current->merge($parent));
Chris@0 54 }
Chris@0 55
Chris@0 56 }