/// <summary>
/// Factory method that parses an unprocessed Expression string and returns an Expression
/// of the appropriate type.
/// </summary>
/// <param name="rawExpression">An unprocessed string for a single expression.</param>
/// <param name="project">The project where the expression exists.</param>
/// <param name="task">The task where the expression exists.</param>
/// <returns>A file expression class.</returns>
public static FileExpressionBase ParseExpression(string rawExpression, ProjectInstance project, ProjectTaskInstance task)
{
string trimmedExpression = rawExpression.Trim();
if (FileExpressionBatched.IsExpression(trimmedExpression))
{
return(new FileExpressionBatched(rawExpression, project, task));
}
if (FileExpressionTransform.IsExpression(rawExpression))
{
return(new FileExpressionTransform(trimmedExpression, project, task));
}
return(new FileExpressionLiteral(rawExpression, project, task));
}
/// <summary>
/// Determines if an expression is a batch expression.
/// </summary>
/// <param name="trimmedExpression">The Expression string with leading and trailing whitespace removed.</param>
/// <returns>True if trimmedExpression is a batch Expression.</returns>
public static bool IsExpression(string trimmedExpression)
{
return(!FileExpressionTransform.IsExpression(trimmedExpression) &&
trimmedExpression.IndexOf("%(", StringComparison.Ordinal) >= 0);
}