Google Wave Identifiers

Abstract

Google Wave is a communication and collaboration platform based on hosted conversations, called waves. A wave comprises a set of concurrently editable structured documents and supports real-time sharing between multiple participants. This document is one in a larger set of specifications for Google Wave. This specification describes Google Wave identifiers, which are used to identify waves, wavelets, and documents.

Table of Contents

1.  Introduction
    1.1.  Document Status
    1.2.  Terminology
    1.3.  Editorial Notes
2.  Overview
3.  Identifier Syntax
4.  Identifier Constraints
    4.1.  Local Identifier
    4.2.  Wave Identifier
    4.3.  Wavelet Identifier
    4.4.  Wavelet Name
5.  References
6.  References
§  Authors' Addresses

1.  Introduction

1.1.  Document Status

This document represents work in progress. It omits details that we are unable to capture at this point and we expect parts of the protocol to change. Please also note that while we revise the protocol and white papers, some transient inconsistencies will occur.

This document is one in a larger set of specifications for Google Wave; see http://www.waveprotocol.org/draft-protocol-specs.

1.2.  Terminology

The capitalized key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.) .

This specification uses the Augmented Backus-Naur Form (ABNF) notation of [RFC5234] (Crocker, D. and P. Overell, “Augmented BNF for Syntax Specifications: ABNF,” January 2008.) . The following ABNF rules are imported from the normative references [RFC5234] (Crocker, D. and P. Overell, “Augmented BNF for Syntax Specifications: ABNF,” January 2008.) , [RFC3986] (Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.) , and [RFC3987] (Duerst, M. and M. Suignard, “Internationalized Resource Identifiers (IRIs),” January 2005.) .:

pct-encoded    =  "%" HEXDIG HEXDIG
unreserved     =  ALPHA / DIGIT / "-" / "." / "_" / "~"
reserved       =  gen-delims / sub-delims
gen-delims     =  ":" / "/" / "?" / "#" / "[" / "]" / "@"
sub-delims     =  "!" / "$" / "&" / "'" / "(" / ")"
               /  "*" / "+" / "," / ";" / "="

iunreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~" / ucschar
ucschar        =  %xA0-D7FF / %xF900-FDCF / %xFDF0-FFEF
               /  %x10000-1FFFD / %x20000-2FFFD / %x30000-3FFFD
               /  %x40000-4FFFD / %x50000-5FFFD / %x60000-6FFFD
               /  %x70000-7FFFD / %x80000-8FFFD / %x90000-9FFFD
               /  %xA0000-AFFFD / %xB0000-BFFFD / %xC0000-CFFFD
               /  %xD0000-DFFFD / %xE1000-EFFFD
ireg-name      = *( iunreserved / pct-encoded / sub-delims )

1.3.  Editorial Notes

To provide feedback on this draft join the wave-protocol mailing list at http://groups.google.com/group/wave-protocol

2.  Overview

A wave identifier provides a simple and extensible means for identifying parts of a wave. This goal of this specification and syntax for wave identifiers is to construct identifiers that may be used as parts of a URI or as a URL query parameter without excessive escaping so that a URI path form is the canonical serialisation. In addition, the syntax is designed to accomodate internationalized identifiers.

In a wave implementation a wave identifier appears on the wire in the federation and client/server protocols, and in addition may be serialized to disk. Wave identifiers may be included in the path or query of an HTTP URI, and should be structured to meet the conflicting goals of uniqueness and clarity when serialized into such URIs.:

http://example.com/waveref/<waveid>

http://example.com/waveref?id=<waveid>

http://example.com/waveref#<waveid>

Note that this draft specification has references to particular documents, offsets, and versions in mind, but does not specify them explicitly at this time.

This specification restricts the allowed character set in a wave id to aid construction of clean and readable URI-references.

3.  Identifier Syntax

A wave identifier is a domain name and a local identifier joined by '/'.

The domain name is a unicode string, and may contain international alphanumeric characters, as described by the IDNA standard [RFC3490] (Faltstrom, P., Hoffman, P., and A. Costello, “Internationalizing Domain Names in Applications (IDNA),” March 2003.) . Future version of this specification will detail serialization, which depends on context.

The local identifier is a non-empty unicode string drawn from the character set:

lchar       = iunreserved / "+" / "*" / "@"
localid     = 1*lchar
waveid      = ireg-name "/" localid

A wavelet identifier is a domain name and a local identifier joined by '/'.:

waveletid = ireg-name "/" localid

A wavelet name is an identifier for a wavelet that includes the wave identifier and the wavelet identifier. It is constructed by concatenating the two identifiers with a "/":

wavename    = waveid "/" waveletid

4.  Identifier Constraints

The constructed wave and wavelet identifiers have differing uniqueness constraints which are described below.

4.1.  Local Identifier

Local identifiers may be structured by an application, but that structure is not specified here.

4.2.  Wave Identifier

For wave identifiers that identify waves, the domain and localid of a wave identifier together as a pair MUST be globally unique.

Example:

example.com/w+2cDs_sd

4.3.  Wavelet Identifier

For identifiers the identify wavelets, the domain and localid of a wavelet identifier together MUST be unique within a wave.

Examples:

tūdaliņ.lv/user+töm@tūdaliņ.lv

example.com/prof+hügo@example.com

tūdaliņ.lv/robot+tweety.appspot.com

4.4.  Wavelet Name

Wavelet names are constructed from wave identifiers and wavelet identifiers that meet their individual constraints, and are thus by construction globally unique.

Example:

example.com/w+2cDs_sd/tūdaliņ.lv/user+töm@tūdaliņ.lv

5.  References

6. References

Authors' Addresses