/// <summary>
/// Fetches a field value from the document, throwing an exception if the field does not exist.
/// </summary>
/// <param name="path">The field path to fetch. Must not be null.</param>
/// <exception cref="InvalidOperationException">The field does not exist in the document data.</exception>
/// <returns>The deserialized value.</returns>
public T GetValue <T>(FieldPath path)
{
var raw = ExtractValue(path);
GaxPreconditions.CheckState(raw != null, $"Field {path} not found in document");
return((T)ValueDeserializer.Deserialize(Database, raw, typeof(T)));
}
/// <summary>
/// Attempts to fetch the given field path from the document, returning whether or not it was found, and deserializing
/// it if it was found.
/// </summary>
/// <remarks>
/// This method does not throw an exception if the field is not found, but does throw an exception if the field was found
/// but cannot be deserialized.
/// </remarks>
/// <typeparam name="T">The type to deserialize the value to, if it is found.</typeparam>
/// <param name="path">The field path to fetch. Must not be null.</param>
/// <param name="value">When this method returns, contains the deserialized value if the field was found, or the default value
/// of <typeparamref name="T"/> otherwise.</param>
/// <returns>true if the field was found; false otherwise.</returns>
public bool TryGetValue <T>(FieldPath path, out T value)
{
var raw = ExtractValue(path);
if (raw == null)
{
value = default(T);
return(false);
}
value = (T)ValueDeserializer.Deserialize(Database, raw, typeof(T));
return(true);
}