Add onenter/onleave callback for data
Fix show/hide API to update y domain - #70
Skip redraw if no targets to show
Add toggle API
Toggle target chart when legend clicked as default
Fix data label when data updated - #99
Add sample for custom x on categorized axis
Add sample for multiple charts
Update samples
Add data.names API - #100
Fix typo
Fix data label update
Fix label and transition for null value
Fix bar chart when hidden
Fix tooltip when data hidden
Fix show/hide for pie/donut chart
Fix show/hide when y2 exists
Fix css - #101