5 Appendix C: hasLayout

To optimize layout, elements in Quirks Mode and IE7 Mode fall into one of the following categories:

  • The element is responsible for sizing and positioning all of its content and that of its child elements. It has layout by default.

  • The element is reliant upon an ancestor element for sizing and positioning and does not have layout.

The hasLayout property is a Document Object Model (DOM) property that indicates when an element has a layout. It is used internally only in quirks mode and IE7 mode to implement CSS positioning. It is not used at all in IE8 mode or IE9 Mode.

The property is true when:

  • An element has layout by default

  • The property of an element that does not have layout by default is assigned a value. Resetting the property value to the element’s default value resets the value of hasLayout to false.