Allow renderers to override _any_color_fmt. (#2490)

Author: asinghvi17

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * Added anchor links to admonition blocks, making it possible to create direct links to specific admonitions. ([#2505], [#2676], [#2688])
 * Added different banners for dev and unreleased docs ([#2382], [#2682])
+* Added an API function `writer_supports_ansicolor` for a Documenter writer to indicate that it supports rendering ANSI-colored strings.  This is useful for new backends that may be implemented. ([#2490])
 
 ### Fixed
 
@@ -1383,7 +1384,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * The at-blocks now support `MIME"text/html"` rendering of objects (e.g. for interactive plots). I.e. if a type has `show(io, ::MIME"text/html", x)` defined, Documenter now uses that when rendering the objects in the document. ([#764])
 
-* Addeds to the sidebar. When loading a page, the sidebar will jump to the current page now. Also, the scrollbar in WebKit-based browsers look less intrusive now. ([#792], [#854], [#863])
+* Added to the sidebar. When loading a page, the sidebar will jump to the current page now. Also, the scrollbar in WebKit-based browsers look less intrusive now. ([#792], [#854], [#863])
 
 * Minor style enhancements to admonitions. ([#841])
 
@@ -1987,6 +1988,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#2480]: https://github.com/JuliaDocs/Documenter.jl/issues/2480
 [#2482]: https://github.com/JuliaDocs/Documenter.jl/issues/2482
 [#2485]: https://github.com/JuliaDocs/Documenter.jl/issues/2485
+[#2490]: https://github.com/JuliaDocs/Documenter.jl/pull/2490
 [#2496]: https://github.com/JuliaDocs/Documenter.jl/issues/2496
 [#2497]: https://github.com/JuliaDocs/Documenter.jl/issues/2497
 [#2499]: https://github.com/JuliaDocs/Documenter.jl/issues/2499

docs/src/lib/public.md

@@ -40,3 +40,12 @@ DocumenterTools.generate
 DocumenterTools.genkeys
 DocumenterTools.OutdatedWarning.generate
 ```
+
+## Extensions
+
+These APIs are intended for extension and plugin authors to use.
+They would normally not be relevant for usual end-users.
+
+```@docs
+Documenter.writer_supports_ansicolor
+```

src/expander_pipeline.jl

@@ -784,13 +784,25 @@ end
 # @example
 # --------
 
-# Find if there is any format with color output
+# Find if there is any format with color output.
 function _any_color_fmt(doc)
-    idx = findfirst(x -> x isa Documenter.HTML, doc.user.format)
+    idx = findfirst(writer_supports_ansicolor, doc.user.format)
     idx === nothing && return false
     return doc.user.format[idx].ansicolor
 end
 
+# General fallback.
+"""
+    writer_supports_ansicolor(::Documenter.Writer)::Bool
+
+Returns whether the writer supports ANSI-colored output (`true`) or not (`false`).
+
+This is usually relevant in Documenter blocks that execute code, like `@example` or `@repl`.
+
+If `true`, these blocks will call `show` on the returned Julia object with `color = true`.  If `false`, then show is called with `color=false`.
+"""
+writer_supports_ansicolor(::Writer) = false
+
 function Selectors.runner(::Type{Expanders.ExampleBlocks}, node, page, doc)
     @assert node.element isa MarkdownAST.CodeBlock
     x = node.element

src/html/HTMLWriter.jl

@@ -581,6 +581,10 @@ struct HTML <: Documenter.Writer
     end
 end
 
+# HTML accepts ANSI, so this is `true`.
+Documenter.writer_supports_ansicolor(::HTML) = true
+
+
 # Cache of downloaded highlight.js bundles
 const HLJSFILES = Dict{String, String}()
 # Look for node and highlight.js