/// <summary>
/// Helper method that evaluates the cell's _value, given its content.
///
/// The value of a cell can be (1) a string, (2) a double, or (3) a FormulaError.
/// (By analogy, the value of an Excel cell is what is displayed in that cell's position
/// in the grid.)
///
/// If a cell's contents is a string, its value is that string.
///
/// If a cell's contents is a double, its value is that double.
///
/// If a cell's contents is a Formula, its value is either a double or a FormulaError.
/// The value of a Formula, of course, can depend on the values of variables. The value
/// of a Formula variable is the value of the spreadsheet cell it names (if that cell's
/// value is a double) or is undefined (otherwise). If a Formula depends on an undefined
/// variable or on a division by zero, its value is a FormulaError. Otherwise, its value
/// is a double, as specified in Formula.Evaluate.
/// </summary>
public void Evaluate(Formula.Lookup lookup)
{
if (_contents is Formula)
{
try
{
_value = _contents.Evaluate(lookup);
}
catch (FormulaEvaluationException)
{
_value = new FormulaError("Formula could not be evaluated.");
}
}
else if (_contents is string || _contents is double)
{
_value = _contents;
}
else
{
throw new Microsoft.CSharp.RuntimeBinder.RuntimeBinderException();
}
}
/// <summary>
/// Initializes this cell, which will be named (name) and contain content (content).
///
/// Note: content will necessarily, by virtue of SetCellContents, be of type string, double,
/// or Formula. However, this constructor still calls SetContent to make sure the object
/// parameter is always an allowable type.
/// </summary>
public Cell(dynamic content, Formula.Lookup lookup)
{
SetContent(content);
Evaluate(lookup);
}