/// <summary>
/// Creates a new <see cref="CatchBlockWrapper<TParent>" /> returning the block representing the catch block.
/// </summary>
/// <param name="parent">The parent to return to once the block has been ended.</param>
/// <param name="type">The type of the exception being caught.</param>
/// <param name="variableName">The variable name of the caught exception.</param>
/// <param name="catchBody">The body of the catch statement to hand back to the calling body to improve the fluent syntax.</param>
/// <returns>The new <see cref="CatchBlockWrapper<TParent>" /> representing the catch statement.</returns>
/// <exception cref="ArgumentNullException">When the <paramref name="parent"/> or <paramref name="type"/> is null, the exception is thrown.</exception>
/// <exception cref="ArgumentException">
/// <para>When <paramref name="type"/> does not derive from <see cref="Exception"/>, the exception is thrown.</para>
/// <para>- Or -</para>
/// <para>When the <paramref name="variableName"/> is non-null and empty or whitespace, the exception is thrown.</para>
/// </exception>
public static CatchBlockWrapper <TParent> Create(TParent parent, Type type, string variableName, out Block <TParent> catchBody)
{
Debug.Assert((parent != null), "The parent argument cannot be null.");
Debug.Assert((type != null), "The type argument cannot be null.");
Debug.Assert(typeof(Exception).IsAssignableFrom(type), "The type argument must derive from Exception.");
ParameterExpression variable;
if (variableName != null)
{
variableName = variableName.Trim();
Debug.Assert((variableName.Length > 0), "The variableName argument cannot be empty or whitespace.");
variable = Expression.Variable(type, variableName);
}
else
{
variable = null;
}
var catchBlockWrapper = new CatchBlockWrapper <TParent>(parent, type, variable);
catchBody = catchBlockWrapper.catchBlock;
return(catchBlockWrapper);
}
/// <summary>
/// Creates a catch block for the try block (no variable and catches all <typeparamref name="TException"/>s).
/// </summary>
/// <typeparam name="TException">The type of the <see cref="Exception"/> to catch.</typeparam>
/// <returns>The catch's <see cref="Block<TParent>"/> to begin inserting statements.</returns>
public Block <Try <TParent> > Catch <TException>() where TException : Exception
{
Block <Try <TParent> > catchBody;
this.lstCatchBlocks.Add(CatchBlockWrapper <Try <TParent> > .Create(this, typeof(TException), null, out catchBody));
return(catchBody);
}
/// <summary>
/// Creates a catch block for the try block (with a variable and catches all <typeparamref name="TException"/>s).
/// </summary>
/// <typeparam name="TException">The type of the <see cref="Exception"/> to catch.</typeparam>
/// <param name="variableName">The variable name of the caught exception.</param>
/// <returns>The catch's <see cref="Block<TParent>"/> to begin inserting statements.</returns>
/// <exception cref="ArgumentException">
/// <para>When the <paramref name="variableName"/> is a name that is null, empty, or whitespace, the exception is thrown.</para>
/// <para>- Or -</para>
/// <para>When the <paramref name="variableName"/> is a name that is already declared, the exception is thrown.</para>
/// </exception>
public Block <Try <TParent> > Catch <TException>(string variableName) where TException : Exception
{
Block <Try <TParent> > catchBody;
if (string.IsNullOrWhiteSpace(variableName))
{
throw new ArgumentException("The variable name cannot be null, empty, or whitespace.", "variableName");
}
variableName = variableName.Trim();
if (this.GetVariablesInScope().Any(x => x.Name == variableName))
{
throw new ArgumentException(string.Format("Variable, {0}, is already declared. Please assign a different name.", variableName));
}
this.lstCatchBlocks.Add(CatchBlockWrapper <Try <TParent> > .Create(this, typeof(TException), variableName, out catchBody));
return(catchBody);
}
