A proposal: Standardised metadata properties in JavaScript libraries

What?

A standard way for developers (be they regular, plugin or library devs) to access things like the version and name of a JavaScript library.

Example

Yes, it's simplified. Focus on the metadata bits and pretend the rest is pure awesomeness.

var jGrouseLib = (function(G){

  // Metadata
  G.type = 'library';
  G.name = 'Grouse Library';
  G.major_version = 1;
  G.minor_version = 2;
  G.patch_version = 3;
  G.special_version = 'b4';
  G.version = '1.2.3b4';
  G.globals = ['jGrouseLib', 'G'];

  // The rest of the library
  // ...

  return window.G = G;
})(jGrouseLib || {});

Why?

• Use cases:
  • plugin developers - checking dependencies
  • library developers - check if another library (or another copy of your own) is using a global you want to
  • regular developers - finding what library is behind $, _ etc.
• CommonJS is awesome
• SemVer is awesome

Why not?

Bloat

Minimal - above example is 167B extra

Can't split version into separate bits

See code samples

Some libraries (Prototype) don't conform to SemVer

They should change, or we should relax it a bit (strip invalid chars etc.)

Library X uses some of those properties for other things

Fair enough, see .meta namespacing discussion.

Details

Properties:

• type, required, string
  • Must be 'library'
• name, required, string
  • The name of the library
• major_version, required, number
• minor_version, required, number
• patch_version, required, number
• special_version, required, string
• version, required, string
  • major_version + '.' + minor_version + '.' + patch_version + special_version
• globals, optional, array of strings
  • Names of the variables you're sticking in the global namespace (i.e. window)

How?

• [backwards compatibilitly]
• [version splitting & concatting functions]

References

1. Common libraries: http://code.google.com/apis/libraries/
2. CommonJS packages metadata http://wiki.commonjs.org/wiki/Packages/1.1
3. Semantic Versioning: http://semver.org/
4. Cross-browser Object.watch(): http://gist.github.com/384583