Messages Module Functions

The protorpc.messages package provides the following positional utility function:

find_definition(name, relative_to=None)

Find definition by name in module-space.

The find algorithm finds definitions by name relative to a message definition or by fully qualified name. If no definition is found relative to the relative_to parameter, it searches against the container of relative_to. If relative_to is a nested Message, it searches its message_definition(). If that message has no message_definition(), it searches its module. If relative_to is a module, the find algorithm searches for the containing module and searches relative to it. If the module is a top-level module, the find algorithm searches for the a message using a fully qualified name. If it still finds no message, the search fails and the method raises a DefinitionNotFoundError.

For example, when looking for any definition foo.bar.ADefinition relative to an actual message definition abc.xyz.SomeMessage:

find_definition('foo.bar.ADefinition', SomeMessage)

The arguments to this method follow a pattern similar to a search for fully qualified names:

abc.xyz.SomeMessage. foo.bar.ADefinition
abc.xyz. foo.bar.ADefinition
abc. foo.bar.ADefinition
foo.bar.ADefinition

When resolving the name relative to Message definitions and modules, the algorithm searches any Messages or sub-modules found in its path, ignoring non-Message values.

A name that begins with '.' is considered to be a fully qualified name. The find algorithm begins searching from the topmost package. For example, assume two message types:

abc.xyz.SomeMessage
xyz.SomeMessage

Searching for .xyz.SomeMessage relative to abc resolves to xyz.SomeMessage and not abc.xyz.SomeMessage. For this kind of name, the relative_to parameter is effectively ignored and always set to None.

For more information about package name resolution, please see the Protocol Buffers Package specifier.

Arguments
name
Name of a definition to find. May be fully qualified or relative.
relative_to
Searches for a definition relative to the message definition or module. If None, causes a fully qualified name search.

Returns an Enum or Message class definition associated with the name.

raises a DefinitionNotFoundError if no definition is found in any search path.