This release adopts ES2015 language features such as for-of and drops support for older browsers, including IE. If you need to support pre-ES2015 environments, you should stick with d3-dispatch 1.x or use a transpiler.

• Disallow whitespace and periods in type names passed to d3.dispatch.
• Add sideEffects: false to the package.json.

• Housekeeping.

• Update dependencies.

• Update dependencies.

• Update dependencies.

• Add module entry point to package.json.

• First stable release.

Changes since D3 3.x

Rather than decorating the dispatch object with each event type, the dispatch object now exposes generic dispatch.call and dispatch.apply methods which take the type string as the first argument. For example, in D3 3.x, you might say:

dispatcher.foo.call(that, "Hello, Foo!");

To dispatch a foo event in D3 4.0, you’d say:

dispatcher.call("foo", that, "Hello, Foo!");

The dispatch.on method now accepts multiple typenames, allowing you to add or remove listeners for multiple events simultaneously. For example, to send both foo and bar events to the same listener:

dispatcher.on("foo bar", function(message) {
  console.log(message);
});

This matches the new behavior of selection.on in d3-selection. The dispatch.on method now validates that the specifier listener is a function, rather than throwing an error in the future.

The new implementation d3.dispatch is faster, using fewer closures to improve performance. There’s also a new dispatch.copy method for making a copy of a dispatcher; this is used by d3-transition to improve the performance of transitions in the common case where all elements in a transition have the same transition event listeners.

See CHANGES for all D3 changes since 3.x.

• Export to the global d3 in vanilla environments (d3/d3#2840).

• Workaround Safari optimizer bug (#11).

• Throw an error the callback passed to dispatch.on is not a function (#8).

• Fix dispatch.constructor (#7).

• Fix optimization warning in dispatch.call.

• Support for multiple typenames with dispatch.on (#6).
• Replace dispatch.type.call with dispatch.call (#4).
• Replace dispatch.type.apply with dispatch.apply (#4).
• Add dispatch.copy (#5).

• Rewrite without closures (#3).

• Define d3-dispatch module (and d3_dispatch global), not dispatch.

• Fixed the main definition in the package.json file.

• Adjusted the package.json definition for npm users.