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Font icons however can be represented by an IIconRef as usual because these do not specify how the icon is created. To see how we would work with font icons let's look at FontIcon, the DomUI component that renders a font icon. This class only expects one or more CSS classes, and it uses these classes to select the font. To actually render a font icon you also need to make sure that the appropriate css file has been included in the header of the page (usually done by adding a HeaderContributor to the DomApplication.initialize() method).
To refer to individual icons in a font's set we have to use the css class names, but this is error prone. A better way is to again define a specific Enum class that represents all of the icons in the font set you use, and then to use those enum values (each implementing IIconRef) as the source for the class name. This again makes icons fully typed and compile time safe as any spelling error in a font icon's name does not compile.
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