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0.12.6 (Jun 2017)

Bokeh Version 0.12.6 is an incremental update that adds a few important features and fixes several bugs. Some of the highlights include:

  • Headless, programmatic export of SVG and PNG images (#538)
  • New annotations Band and Whisker for displaying error estimates (#2352)
  • Fine-grained sub-element patching for images and other “multi” glyphs (#6285)
  • Hover hit-testing extended to segments and all markers (#5907, #5907)
  • Fixes for sorting and selecting from DataTables (#3564, #6115)
  • Large cleanup and refactor of the layout system (#4764, #4810, #5131, #5518, #6213, #6287)
  • Improved formatting options for hover tool fields and axis tick labels (#1239, #1671, #2595, #6079)

Many other bugfixes and docs additions are also included. For full details see the CHANGELOG.

NOTE: the 0.12.x series is the last planned release series before a version 1.0 release. The focus of the 1.0 release will be implementing build automation to enforce API stability, and a very small number of high value features. For more information see the project roadmap.

Migration Guide

As the project approaches a 1.0 release, it is necessary to make some changes to bring interfaces and functionality up to a point that can be maintained long-term. We try to limit such changes as much as possible, and have a period of deprecation.

New deprecations

The Plot.webgl property has been deprecated in place of a new property Plot.output_backend in order to avoid conflicts between WebGL and a new SVG backend. If you are using plot.webgl = True, you should switch to setting plot.output_backend = "webgl" for the future.

Old deprecations removed

All previous deprecations up to 0.12.3 have be removed. Below is the complete list of removals.

  • Deprecated Button.type property has been removed.
  • Deprecated Legend properties: legends, legend_margin, legend_padding, legend_spacing have been removed.
  • Deprecated DatetimeTickFormatter.formats property has been removed.
  • Tool dimensions may not only be specified with enum values.

New models for Scales

The following BokehJS classes have been moved and renamed:

Old New
mappers/LinearMapper scales/LinearScale
mappers/LogMapper scales/LogScale
mappers/CategoricalMapper scales/CategoricalScale

Previously, these Mapper classes were internal implementation details. The new Scale classes are first-class Bokeh models and are accessible from Python. This was done to facilitate future work supporting custom, user-defined scales.

There is a new Plot validation check to ensure that Scales and Ranges on a dimension are compatible. By default, Plot models are configured with LinearScale models which (along with LogScale models) are compatible with Range1d and DataRange1d range models.

One inevitable breaking change is that users employing a FactorRange in the bokeh.model API will have to specify a CategoricalScale on the same dimension. For example:

plot = Plot()
plot.x_range = DataRange1d()
plot.y_range = FactorRange(["Mon", "Tues", "Wed", "Thurs", "Fri"])
plot.y_scale = CategoricalScale()

The bokeh.plotting.figure function should this range and scale compatibility handling automagically in most cases.

As part of this work, some BokehJS attributes were renamed to be consistent with the new terminology:

Old New
CartesianFrame.x_mappers CartesianFrame.xscales
CartesianFrame.y_mappers CartesianFrame.yscales
GlyphRenderer.xmapper GlyphRenderer.xscale
GlyphRenderer.ymapper GlyphRenderer.yscale

Since these attributes may be present in user code (e.g CustomJS callbacks or extensions), the old names will continue to work for some time, with a deprecation warning in the JS console.

New signaling API

Previously BokehJS used Backbone events for communication between models. As part of an ongoing migration to TypeScript, the Backbone dependency was removed, and the relevant portion replaces with a minimal, type-safe API for signaling.

This change primarily affects contributors working on BokehJS and writers of extensions.

Old New
@listenTo(obj, 'change', fn) @connect(obj.change, fn)
@listenTo(obj, 'change:attr', fn) @connect(obj.properties.attr.change, fn)
obj.trigger('change', arg) obj.change.emit(arg)
obj.trigger('change:attr', arg) obj.properties.attr.change.emit(arg)

Python Datetime handling

Bokeh has not handled Python datetime values consistently with NumPy datetime64. Bokeh aims to treat all datetime values “as-is”, but in some cases a local timezone conversion could affect Python datetime values. This has been corrected. In case there is code that depends on the erroneous behavior, please note that the new behavior is effective immediately and is now maintained under test to be consistent with NumPy values. See the issue #5499 for more details.

Layout API and behaviour changes

Layout was previously handled on document level and there was one solver per document. This was changed to one solver per root, so document isn’t anymore responsible for any layout related stuff. All logic and APIs were moved to views, specifically to LayoutDOM. For example, if your code relied on document.resize(width, height), then you should use view.resize(width, height), where view is an associated view of any of document’s root models. Views can be obtained through Bokeh.index. To resize all roots use

for (var key in Bokeh.index) {
    Bokeh.index[key].resize(width, height);
}