Vega should draw legends about vega

[veroshin]

+1. Need legends too

[tony612]

I noticed that there is code about legend already: trifacta/vega@b3b3b7d

But it seems that there is not document about that

[jheer]

Initial legend support has been committed, but is still being refined and finalized. If you're feeling impatient, you can try the following in the editor, running locally with the latest commit...

In the choropleth example add:

  "padding": {"top":0, "left":0, "bottom":0, "right":120},
  "legends": [{"fill":"color"}],

In the stocks example add:

  "padding": {"top":10, "left":40, "bottom":20, "right":140},
  "legends": [{"stroke":"color", "orient":"left", "offset":-110}],

The currently supported legend types are "fill", "stroke", "size" and "shape". For redundant encodings with ordinal scales, multiple types can be used. Future commits will further refine legend positioning and sizing; official documentation will then follow.

[jheer]

Legend support should now be complete for the imminent 1.3 release. Documentation is forthcoming, but some of the updated examples (scatter and scatter_matrix) demonstrate the use of legends.