Function getEffectiveLayoutInternal

src/core/static-layout.js:238–364

* Gets the effective layout for an element. * * If class 'i-amphtml-layout' is present, then directly use its value. * Else calculate layout based on element attributes and return the width/height. * * @param {Element} element * @return {InternalEffectiveLayoutDef}

(element)

 * @return {InternalEffectiveLayoutDef}
 */
function getEffectiveLayoutInternal(element) {
  // Parse layout from the element.
  const layoutAttr = element.getAttribute('layout');
  const widthAttr = element.getAttribute('width');
  const heightAttr = element.getAttribute('height');
  const sizesAttr = element.getAttribute('sizes');
  const heightsAttr = element.getAttribute('heights');

  // Input layout attributes.
  const inputLayout = layoutAttr ? parseLayout(layoutAttr) : null;
  userAssert(
    inputLayout !== undefined,
    'Invalid "layout" value: %s, %s',
    layoutAttr,
    element
  );
  /**
   * @type {string|null|undefined}
   * @const
   */
  const inputWidth =
    widthAttr && widthAttr != 'auto' ? parseLength(widthAttr) : widthAttr;
  userAssert(
    inputWidth !== undefined,
    'Invalid "width" value: %s, %s',
    widthAttr,
    element
  );
  /**
   * @type {string|null|undefined}
   * @const
   */
  const inputHeight =
    heightAttr && heightAttr != 'fluid' ? parseLength(heightAttr) : heightAttr;
  userAssert(
    inputHeight !== undefined,
    'Invalid "height" value: %s, %s',
    heightAttr,
    element
  );

  // Effective layout attributes. These are effectively constants.
  let width;
  let height;
  let layout;

  // Calculate effective width and height.
  if (
    (!inputLayout ||
      inputLayout == Layout_Enum.FIXED ||
      inputLayout == Layout_Enum.FIXED_HEIGHT) &&
    (!inputWidth || !inputHeight) &&
    hasNaturalDimensions(element.tagName)
  ) {
    // Default width and height: handle elements that do not specify a
    // width/height and are defined to have natural browser dimensions.
    const dimensions = getNaturalDimensions(element);
    width =