MICROSOFT_PRESS_EBOOK_PROGRAMMING_WINDOWS_8_APPS_WITH_HTML_CSS_AND_JAVASCRIPT_PDF

Command Menus
The next aspect of an app bar we need to explore in a little more depth are those commands whose
type property is set to flyout. In this case the command’s flyout property must identify a
WinJS.UI.Flyout object or a WinJS.UI.Menu control (which is a flyout). As noted before, flyout or popup
menus like this are used when there are too many related commands cluttering up the basic app bar, or
when you need other types of controls that aren’t quite appropriate on the app bar itself. It’s said,
though, that if you’re tempted to use a button labeled “More”, “Advanced”, or “Other Stuff” because
you can’t figure out how to organize the commands otherwise, it’s a good sign that the app itself is too
complex! Seek ways to simplify the app’s purpose so that the app bar doesn’t just become a repository
for randomness.
We’ll be covering flyouts more fully a little later in this chapter, but let’s see how to use one in an app
bar, as demonstrated in Scenario 6 of the HTML flyout control sample (not the app bar sample, mind
you!):
In html/appbar-flyout.html of this sample we see the app bar button declared as follows:
The respondFlyout element identified here is defined earlier in html/appbar-flyout.html; note that
such an element must be declared prior to the app bar to make sure it’s instantiated before the app bar
is created:
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