HTML and CSS Reference
attributes). Also, since http://schema.org was launched by several large corpor-
ations with vested interests in search engine technology, the neutrality of the syntaxes
advocated by this website have been questioned. It is, however, a good starting point to
familiarize yourself with the concepts of annotating your page content.
4 Microdata actually evolved from RDFa.
Undo manager API
The undo manager API is a new interface for allowing a web page access to the undo/
redo transaction manager inside the web browser. What does this mean? Well, think
about when you type some text in the search bar in a web browser; you will likely be
able to select Edit Undo to undo the text that you entered. This is the browser's native
undo manager allowing you to undo an operation you have done. However, if you have
an interactive web application, such as a rich text editor or drawing application built on
not pick up the modifications performed by the script. This is where the undo man-
ager API would come in, because it would provide a method to add actions performed
adding URLs to the history “stack,” the undo manager allows a particular set of changes
to the page (together called a transaction) to be added to the browser's native undo stack.
Since this feature is still under development, don't expect it to work in browsers today,
but keep it in mind as a capability that will likely arrive in browser implementations in
the not-too-distant future.
Upcoming CSS technologies
As you know, this one isn't an HTML5 technology, but it goes hand in hand with HTML.
As there are many developments in HTML5, there are also many in CSS3. An inter-
esting area has to do with page layout, and the specifications in this area have yet to
fully coalescence into a dominant method(s). Eventually it's expected there will be three
Box Layouts, 5 or FlexBox, which provides better alignment and positioning of elements
within their parent container; and grid/template/region layouts. Currently, grid/template/
region layouts are broken into four distinct specifications, but these will likely merge in
the future. Grid positioning and grid layouts are for handling rows and columns and
specifying how elements are positioned in this type of layout (a multicolumn layout can
already be thought of as a rowless grid layout). The template layout uses a grid as well
but defines a template such as “abc” or “bca,” where each of the letters corresponds to an