NEWS in package ‘htmlwidgets’

Changes in version 1.5.4

Closed #320: getDependency() no longer includes an absolute src path in its return value. (#384)
Fixed #408: An error type-check did not work correctly because it was missing parentheses. (#409)

Added a reportTheme argument to shinyWidgetOutput(). If TRUE, CSS styles of the widget's output container are made available to shiny::getCurrentOutputInfo(), making it possible to provide 'smart' styling defaults in a renderWidget() context. (#361)
shinyRenderWidget() now has a cacheHint parameter, for use with Shiny's new bindCache() function. (#391)
Support a new PACKAGE::widget_html.WIDGETNAME convention for defining custom widget HTML. This replaces the earlier PACKAGE::WIDGETNAME_html convention, which continues to work but may be deprecated at some point in the future. The goal for the new convention is to prevent accidentally matching functions that were never intended for this purpose. (Thanks, @thebioengineer!) (#376)
Export the JSEvals function, allowing other packages to support JS() in non-widget contexts.

saveWidget() now file argument now properly handles relative paths. (#299)
Fixed an issue with passing named function declarations to JS() and onRender() (introduced by v1.4). (#356)

Emergency patch release to fix an issue with rendering htmlwidgets in flexdashboard. More generally, this change implies that any htmlwidget is printed via a knitr code chunk with multiple values for fig.width/fig.height, only the first value is used for the widget's sizing policy. (#387)

Fixed an issue with dynamically rendered widgets (i.e., using shiny::uiOutput() to render a widget) with any version of shiny prior to 1.4. This issue was introduced by htmlwidgets 1.5. (#351)

Fixed an incompatibility with Shiny v1.4.0: due to Shiny upgrading from jQuery 1.x to 3.x, the timing of some initialization routines has changed. This caused some widget renderValue calls to occur at an earlier point in Shiny's initialization process than with earlier versions of Shiny. (#345)

JavaScript statements can now be passed along to onRender() and JS() (#329).

All files and directories under the inst/htmlwidgets/ directory of a widget package will be copied when a widget is rendered due to an unintended change in #306. Only the single WIDGET.js file should be copied (where WIDGET is the widget name). Fixed via #312.
Support for async Shiny. Widget render functions that use the default implementation of htmlwidgets::shinyRenderWidget can receive promises of widget objects (you can, of course, continue to use regular widget objects as well).

See https://rstudio.github.io/promises for more about async Shiny.

htmlwidgets can be created without a package, without yaml, and/or without JavaScript binding. (#304, #305)
Use RStudio Page Viewer for full page widgets.
Fix #297: Setting background in saveWidget() is broken

The saveWidget's background parameter could not process hex color codes, due to changes introduced in htmlwidgets 1.0. (#297)

Fix issues with self-contained mode when used with new versions of pandoc. (#289)

Starting with R 3.4.0, a "Calling 'structure(NULL, *)' is deprecated" warning would occur when shinyRenderWidget encountered a NULL value. (#269)
Fix edge case where using dynamic HTML dependencies from a widget binding's JS factory function would fail.

Pass knitr options to saveWidget
Ensure that scaffoldWidget opens files correctly within RStudio
The resize handler also works for the JavaScript events shown.bs.collapse and hidden.bs.collapse now so that widgets inside the Bootstrap collapse class can be displayed
Fix references to vignettes in documentation
Add elementId parameter to widget function generated by scaffoldWidget
More robust method of generating unique widget IDs
Modify advanced and sizing vignettes to use new style widget declarations

Introduce new scheme for defining JavaScript bindings that will make it easier for widgets to gain access to other widget instances on the page.
Add onRender hook for widgets to execute custom JavaScript code after rendering.
Add appendContent and prependContent functions for adding HTML to a widget rendered in a static context (i.e. R console or Rmd)
Fix a bug where the string "" in the widget data caused saveWidget() to have malformed output. (#168)
Tweak pandoc conversion used in saveWidget to prevent hanging with large htmlwidget script data elements (use "markdown" rather than "markdown-strict" as input format)
Increase pandoc stack size to 512M for saveWidget (often required for e.g. larger embedded leaflet maps). Stack size can also be controlled by the pandoc.stack.size option.
Import latest version of with_pandoc_safe_environment from rmarkdown
Fix issue that prevented calling renderValue() from within resize()

Add background parameter to saveWidget function
Fix a bug where "" appearing in widget data would break parsing
Fix a bug where multiple widgets on a page caused all but one to miss resize events
Sync vignettes with contents of htmlwidgets website