(posted by Bill Hesse)
By wrapping the string literal in a function that takes the context as
a parameter, you can have a Function : context -> String that you can
pass around instead of a String. If you need to use some String
operations, like concat, on these objects, you can implement these
operations on a class encapsulating this type ("lifting" them). This
seems like a straightforward way to give the string literal in one
place, and give the data you want to interpolate in another.
String interpolation always happens dynamically, each time the literal
is used, and the data can easily come from a parameter to a function
rather than from the lexical context.
For example:
Function MyTemplate() {
return (Context context) {
return "<table><tr><td class=${context.leftColumnClass}>Red Sox</td><td>${context.data}</td></tr></table>";
}
}
...
var templateHere = MyTemplate();
...
var output = templateHere(context);
You could also skip a level of indirection and just create
String FillMyTemplate(Context context) => '''
<html><head><title>$context.title</title></head>
''';
and use FillMyTemplate where you need the template.
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