Beta release of v3.0.0-beta.8

• Modify expression logging functions (warn, info, debug) to accept a variable number of arguments and always return the last provided argument. (vega/vega-parser#6)
• Add extensible renderer modules, export rendererModule registry function as part of top-level Vega object.
• Fix DOM binding re-initialization. (vega/vega-view#2)
• Fix signal updater return value logic. (vega/vega-dataflow#14)
• Update Vega npm build script to bypass tests for faster iteration. (#670)

Beta release of v3.0.0-beta.7

• New href encoding property for creating hyperlinks.
• Output SVG tags now include viewBox attribute to aid resizing.
• The vega-loader sanitize method now returns a hash of link attributes, not a URL string. The output URL string is available under the "href" property.
• Standardize and export band scale space calculation.
• Add new bandspace expression language function to aid layout calculation.
• Add additional remove options for modify expression language function (and also trigger remove directive). In addition to true (for remove all) and exact tuple removal, one can now pass an object. Tuples whose properties match all defined properties on the parameter object will be removed.
• Add bar-rangestep example to test step-driven band scale layout.
• Update nested-plot example to demonstrate nested layout calc with band scales.
• Fix facet parent tuple lookup bug.
• Fix transform signal tuple propagation bug.

Beta release of v3.0.0-beta.6.

• Add logging expression language functions: warn, info, debug
• Add date-time utilities to expression language: monthFormat, monthAbbrevFormat, dayFormat, dayAbbrevFormat, quarter, utcquarter
• Change signature of expression language format functions to (value, specifier)
• Rename bandSize scale property to rangeStep, update corresponding range calculation to match D3.
• Add scope event source, which limits view events to the sub-group in which the signal is defined.
• Add name property for axes and legends, export as CSS class under SVG renderering.
• Update SVG rendering to include mark role (e.g., "role-axis") as exported CSS class.
• Fix bug when referencing data transform signals defined in the same transform pipeline.
• Fix bug in size legend generation and layout.
• Fix bug in event-selector string parsing.
• Update JSON schema, add schema for geographic projections.

Beta release of v3.0.0-beta.4.

• Add axis "gridScale" directive to configure gridline extent relative to an orthogonal scale.
• Add toggle flags for axis "tick" and "label".
• Rename and consolidate axis "tickPadding" / "tickLabelPadding" to "labelPadding".
• Minor updates to example specs.
• Update JSON schema.
• Add "browser" directive to package.json.
• Add version number to output bundle.

Beta release of v3.0.0-beta.3.

• Exposes text metrics.
• Improves test cases, including cross-platform execution.

Beta release of v3.0.0-beta.2.

Beta release of Vega 3.0.0-beta.1.

• An interactive debugger is now available on the Vega Live Editor -- click the bug icon in the top left-hand side toolbar. Documentation on how to use the debugger is forthcoming. In the meanwhile, see our recent UW IDL research paper for more information.
• Expanded support for theme configurations. Themes specify values for the default "look and feel" of Vega visualizations. Thus, the same JSON specification can produce different charts by varying the values in the theme. The Vega Editor now also offers an additional pane to edit the configuration, along with a number of example themes that emulate Excel-, ggplot2-, Quartz-, and Vox-style charts.
• Support for custom shapes that can be used with symbol marks and legends.
• Legends can now be created for scales that determine mark opacity.
• parent is now a bound variable available with mark-based expressions (h/t @floribon).
• Fixed bug with eventGroup returning group marks marked as uninteractive.
• Fixed bug with formula transforms incorrectly marking a field as updated.
• Fixed bug with the voronoi transform computing empty cells.
• Fixed bug with guides nested within group marks not updating if a higher-level scale is updated.
• Fixed bug with nested signal references used as parameters to transforms.
• Fixed bug with datalib that incorrectly sorted values that included null and NaN.

• Top-level predicate definitions have been deprecated. Test expressions can now be specified inline as part of a production rule.

• Additional scale, iscale, inrange, and indata functions have been added to the expression language to cover functionality provided by deprecated predicates. Note: these functions may only be used in signal stream definitions or production rule test expressions.

• Vega now styles the mouse pointer based on a new cursor mark property or specially-named cursor signal.

• A new rank transform computes an ascending rank score for data tuples based on key fields or their observed order.

• field is now an optional parameter for the Streaming Data operators if the signal value is an object. If field is specified for object signal values, it is used as a key field for toggle and removals (i.e., the datum whose field matches that of the signal value is toggled or removed). If no field is specified, all properties found in the signal value object are used as key fields.

  To update existing specifications to correspond to this behaviour:

  1. If a field is used in a "modify" transform, and the corresponding signal returns an object in its expr definition, ensure that the field matches the key property/properties of the object.
  2. Update any references made to data values found in this modified dataset. Signal values are no longer nested under the modified field, but are at the top-level; their properties can be referenced directly.

  For example, see the diff for the DimpVis example triggered by this change. The field of the toggle transform in the trackCountries dataset was changed to country (a field found on the active signal object). When using data values from this dataset, we can reference fields directly, rather than via a nested property.

• Canonical example specifications are now included with every release.

• The event selector syntax has been extracted to a separate vega-event-selector package available over NPM.

• The bandWidth property of ordinal scales has been renamed to bandSize.

• Clearer error messages are thrown if an unknown transform, signal, or data source is used (h/t @nyurik).

• Fixed bug with offeting axis titles (h/t @floribon).

• category20b and category20c added to the schema as permissable values for scale ranges (h/t @okal).

• Fixed bug with scale function being exposed as axis labels (#440).

• Fixed bug with legend offseting when axis displayed grid lines (#476).

• Fixed bug with grid lines not extending correctly when axes are offset (#519).

• Legends and axis should now share the same formatter options (#504, #506).

Vega:

• New Treeify transform and Hierarchy layouts are now available. See #425 for example specifications.
• The top-level width, height, and padding are now automatically available as correspondingly named signals. Note: these are now reserved signal names, and thus may require existing signals to be renamed.
• The root group mark can be styled with the new top-level scene property.
• Axis titles are now automatically offset from the labels to prevent overlap. An explicit offset can still be specified via the titleOffset property.
• The signature of vg.parse.spec has been standardized, with the callback as the last argument, to facilitate use with Promises (h/t @nyurik, #447).
• The callback passed to vg.parse.spec has also been standardized with a cb(error, chart) signature. For backwards compatibility, cb(chart) continues to be supported, but is deprecated (h/t @nyurik, #447).
• Exposed vg.logging interface for logging messages, errors, and debug output (h/t @nyurik).
• The sort.order property for ordinal scales was deprecated in v2.2.5 and has now been removed to reduce confusion.
• Added a new bin_mid output field to the Bin transform.
• Fixed several bugs with the Cross transform, thanks to @Jerrythafast (#395, #422, #428, #428, #442, #450). Note: the diagonal parameter only applies if a dataset is being crossed with itself.
• Fixed bug with scales being computed prematurely for new streaming faceted groups (h/t @Jerrythafast, #424).
• Fixed bug with placement of right-oriented axes and legends (#422).
• Fixed bug with multiple data points being added by modify operators (h/t @Jerrythafast, #409).
• Fixed bug with sandboxing of scoped scale references (h/t @russelsprouts, #444 & #449).
• Fixed bug with bounds recalculation on axis when width/height/padding was changed (#429).
• Fixed bug with legends not updating to reflect streaming data (h/t @Jerrythafast, #435).
• Fixed bug with the Aggregate transform not reflowing tuples as modified.
• Fixed bug with calling View.padding('auto') (h/t @Jerrythafast, #411).
• Fixed bug with HeadlessView (h/t @joneshf, #405).
• Fixed bugs with the schema for the Treemap and Wordcloud layouts.

Vega Dataflow:

• Exposed Node.rerank to enable reranking of a node and its listeners.
• Fixed bug with synchronizing previous values of tuples when specification contains only datasets.
• Fixed bug with Collectors reusing changesets and causing cross-datasource pollution (h/t @Jerrythafast, #439).