Dash for R v0.5.0

Added

• Dash for R now depends on the brotli package explicitly; previously it was loaded when importing reqres. #204

Changed

• Dash for R no longer wraps the layout in an htmlDiv internally, for parity with Dash for Python. Starting in v0.5.0, the layout method only accepts a single argument, and that argument must be a Dash component or a function that returns a Dash component. #121
• Package documentation has been significantly refactored to use new features of roxygen2 when documenting R6 classes
• The title method now specifies Dash as the default application title instead of dash. #200

Fixed

• A minor bug in validate_keys which prevented interpolate_index from working as intended has been resolved