/// <summary>
/// Get the value of a property on this object at the specified path
/// </summary>
/// <param name="obj"></param>
/// <param name="path">The path, consisting of property names and sub-property names
/// separated by '.' characters. For example: 'PropertyName.SubPropertyName.SubSubPropertyName' etc.
/// Parameterless methods may also be invoked by adding '()', i.e.:
/// 'PropertyName.SubMethodName().SubSubPropertyName'.
/// Methods and properties on the optional context object may also be invoked in the same way, via a
/// '*' redirection. For example: '*.MethodName()'. When switching to the context
/// object the SetSourceObject method on it will be called and the current object or property value
/// passed in. This allows for complex operations to be performed in order to return a value
/// provided that functionality is implemented in a suitable context object provided.</param>
/// <param name="context">The (optional) string conversion context object. If supplies this allows
/// the '*' symbol to be used within property paths in order to access properties and
/// functions supplied on the context object.</param>
/// <returns></returns>
public static object GetFromPath(this object obj, string path, IStringConversionContext context = null)
{
foreach (string substring in path.Split(new char[] { '.' }, StringSplitOptions.RemoveEmptyEntries))
{
string token = substring;
if (obj == null)
{
return(null);
}
Type type = obj.GetType();
if (token.EqualsIgnoreCase(TextFormat.CONTEXT))
{
context.SetSourceObject(obj);
obj = context;
}
else if (token.EndsWith("()")) // Method
{
MethodInfo info = type.GetMethod(token.TrimEnd(')', '('), new Type[] { });
if (info == null)
{
return(null);
}
else
{
obj = info.Invoke(obj, null);
}
}
else // Property...
{
PropertyInfo info;
string key = null;
if (token.EndsWith("]"))
{
token = token.TrimEnd(']');
int keyStart = token.LastIndexOf('[');
if (keyStart >= 0)
{
key = token.Substring(keyStart + 1);
token = token.Substring(0, keyStart);
if (keyStart == 0)
{
token = "Item";
}
}
}
if (key != null)
{
info = type.GetProperty(token, new Type[] { key.GetType() });
if (info == null)
{
//Property accessor isn't indexed, but maybe the object itself is...
info = type.GetProperty(token);
if (info != null)
{
obj = info.GetValue(obj, null);
if (obj != null)
{
info = obj.GetType().GetProperty("Item", new Type[] { key.GetType() });
}
}
}
}
else
{
info = type.GetProperty(token);
}
if (info == null)
{
//...or Field?
FieldInfo fInfo = type.GetField(token);
if (fInfo == null)
{
return(null);
}
else
{
obj = fInfo.GetValue(obj);
}
}
else
{
if (key != null)
{
obj = info.GetValue(obj, new object[] { key });
}
else
{
obj = info.GetValue(obj, null);
}
}
}
}
return(obj);
}
