Refactor MIME rendering to make it extensible!

Author: asinghvi17

src/writer.jl

@@ -387,104 +387,151 @@ function render(io::IO, mime::MIME"text/plain", node::Documenter.MarkdownAST.Nod
 end
 
 # Select the "best" rendering MIME for markdown output!
+
+"""
+    mime_priority(mime::MIME)::Float64
+
+This function returns a priority for a given MIME type, which
+is used to select the best MIME type for rendering a given
+element.
+"""
+function mime_priority end
+mime_priority(::MIME"text/markdown") = 1.0
+mime_priority(::MIME"text/html") = 2.0
+mime_priority(::MIME"image/svg+xml") = 3.0
+mime_priority(::MIME"image/png") = 4.0
+mime_priority(::MIME"image/webp") = 5.0
+mime_priority(::MIME"image/jpeg") = 6.0
+mime_priority(::MIME"image/png+lightdark") = 7.0
+mime_priority(::MIME"image/jpeg+lightdark") = 8.0
+mime_priority(::MIME"image/svg+xml+lightdark") = 9.0
+mime_priority(::MIME"image/gif") = 10.0
+mime_priority(::MIME"video/mp4") = 11.0
+mime_priority(::MIME"text/plain") = 12.0
+mime_priority(::MIME) = Inf
+
+function render_mime(io::IO, mime::MIME, node, element, page, doc; kwargs...)
+    @warn("DocumenterVitepress: Unknown MIME type $mime provided and no alternatives given.  Ignoring render!")
+end
+
+function render_mime(io::IO, mime::MIME"text/markdown", node, element, page, doc; kwargs...)
+    println(io, element)
+end
+
+function render_mime(io::IO, mime::MIME"text/html", node, element, page, doc; kwargs...)
+    println(io, element)
+end
+
+function render_mime(io::IO, mime::MIME"image/svg+xml", node, element, page, doc; kwargs...)
+    # NOTE: It seems that we can't simply save the SVG images as a file and include them
+    # as browsers seem to need to have the xmlns attribute set in the <svg> tag if you
+    # want to include it with <img>. However, setting that attribute is up to the code
+    # creating the SVG image.
+    image_text = d[MIME"image/svg+xml"()]
+    # Additionally, Vitepress complains about the XML version and encoding string below,
+    # so we just remove this bad hombre!
+    bad_hombre_string = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" |> lowercase
+    location = findfirst(bad_hombre_string, lowercase(image_text))    
+    if !isnothing(location)
+        image_text = replace(image_text, image_text[location] => "")
+    end
+    println(io, image_text)
+end
+
+function render_mime(io::IO, mime::MIME"image/png", node, element, page, doc; kwargs...)
+    filename = String(rand('a':'z', 7))
+    write(joinpath(dirname(page.build), md_output_path, "$(filename).png"),
+        base64decode(element))
+    println(io, "![]($(filename).png)")
+end
+
+function render_mime(io::IO, mime::MIME"image/webp", node, element, page, doc; kwargs...)
+    filename = String(rand('a':'z', 7))
+    write(joinpath(dirname(page.build), md_output_path, "$(filename).webp"),
+        base64decode(element))
+    println(io, "![]($(filename).webp)")
+end
+
+function render_mime(io::IO, mime::MIME"image/jpeg", node, element, page, doc; kwargs...)
+    filename = String(rand('a':'z', 7))
+    write(joinpath(dirname(page.build), md_output_path, "$(filename).jpeg"),
+        base64decode(element))
+    println(io, "![]($(filename).jpeg)")
+end
+
+function render_mime(io::IO, mime::MIME"image/png+lightdark", node, element, page, doc; kwargs...)
+    fig_light, fig_dark, backend = element
+    filename = String(rand('a':'z', 7))
+    write(joinpath(dirname(page.build), md_output_path, "$(filename)_light.png"), fig_light)
+    write(joinpath(dirname(page.build), md_output_path, "$(filename)_dark.png"), fig_dark)
+    println(io,
+        """
+        ![]($(filename)_light.png){.light-only}
+        ![]($(filename)_dark.png){.dark-only}
+        """
+    )
+end
+
+function render_mime(io::IO, mime::MIME"image/jpeg+lightdark", node, element, page, doc; kwargs...)
+    fig_light, fig_dark, backend = element
+    filename = String(rand('a':'z', 7))
+    Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_light.jpeg"), fig_light)
+    Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_dark.jpeg"), fig_dark)
+    println(io,
+        """
+        ![]($(filename)_light.jpeg){.light-only}
+        ![]($(filename)_dark.jpeg){.dark-only}
+        """
+    )
+end
+
+function render_mime(io::IO, mime::MIME"image/svg+xml+lightdark", node, element, page, doc; kwargs...)
+    fig_light, fig_dark, backend = element
+    filename = String(rand('a':'z', 7))
+    Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_light.svg"), fig_light)
+    Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_dark.svg"), fig_dark)
+    println(io,
+        """
+        <img src = "$(filename)_light.svg" style=".light-only"></img>
+        <img src = "$(filename)_dark.svg" style=".dark-only"></img>
+        """
+    )
+end
+
+function render_mime(io::IO, mime::MIME"image/gif", node, element, page, doc; kwargs...)
+    filename = String(rand('a':'z', 7))
+    write(joinpath(dirname(page.build), md_output_path, "$(filename).gif"),
+        base64decode(element))
+    println(io, "![]($(filename).gif)")
+end
+
+function render_mime(io::IO, mime::MIME"video/mp4", node, element, page, doc; kwargs...)
+    filename = String(rand('a':'z', 7))
+    write(joinpath(dirname(page.build), md_output_path, "$(filename).mp4"),
+        base64decode(element))
+    println(io, "<video src='$filename.mp4' controls='controls' autoplay='autoplay'></video>")
+end
+
+function render_mime(io::IO, mime::MIME"text/plain", node, element, page, doc; kwargs...)
+    return render(io, mime, node, Markdown.Code(element), page, doc; kwargs...)
+end
+
 function render(io::IO, mime::MIME"text/plain", node::Documenter.MarkdownAST.Node, d::Dict{MIME, Any}, page, doc; kwargs...)
 
     settings_ind = findfirst(x -> x isa MarkdownVitepress, doc.user.format)
     settings = doc.user.format[settings_ind]
     md_output_path = settings.md_output_path
 
-    filename = String(rand('a':'z', 7))
-    if haskey(d, MIME"text/markdown"())
-        println(io, d[MIME"text/markdown"()])
-    elseif haskey(d, MIME"text/html"())
-        println(io, d[MIME"text/html"()])
-    elseif haskey(d, MIME"image/svg+xml"())
-        # NOTE: It seems that we can't simply save the SVG images as a file and include them
-        # as browsers seem to need to have the xmlns attribute set in the <svg> tag if you
-        # want to include it with <img>. However, setting that attribute is up to the code
-        # creating the SVG image.
-        image_text = d[MIME"image/svg+xml"()]
-        # Additionally, Vitepress complains about the XML version and encoding string below,
-        # so we just remove this bad hombre!
-        bad_hombre_string = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" |> lowercase
-        location = findfirst(bad_hombre_string, lowercase(image_text))    
-        if !isnothing(location)
-            image_text = replace(image_text, image_text[location] => "")
-        end
-        println(io, image_text)
-    elseif haskey(d, MIME"image/png"())
-        write(joinpath(dirname(page.build), md_output_path, "$(filename).png"),
-            base64decode(d[MIME"image/png"()]))
-        println(io,
-            """
-    ![]($(filename).png)
-    """)
-    elseif haskey(d, MIME"image/webp"())
-        write(joinpath(dirname(page.build), md_output_path, "$(filename).webp"),
-            base64decode(d[MIME"image/webp"()]))
-        println(io,
-            """
-    ![]($(filename).webp)
-    """)
-    elseif haskey(d, MIME"image/jpeg"())
-        write(joinpath(dirname(page.build), md_output_path, "$(filename).jpeg"),
-            base64decode(d[MIME"image/jpeg"()]))
-        println(io,
-            """
-    ![]($(filename).jpeg)
-    """)
-    elseif haskey(d, MIME"image/png+lightdark"())
-        fig_light, fig_dark, backend = d[MIME"image/png+lightdark"()]
-        write(joinpath(dirname(page.build), md_output_path, "$(filename)_light.png"), fig_light)
-        write(joinpath(dirname(page.build), md_output_path, "$(filename)_dark.png"), fig_dark)
-        println(io,
-            """
-            ![]($(filename)_light.png){.light-only}
-            ![]($(filename)_dark.png){.dark-only}
-            """
-        )
-    elseif haskey(d, MIME"image/jpeg+lightdark"())
-        fig_light, fig_dark, backend = d[MIME"image/jpeg+lightdark"()]
-        Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_light.jpeg"), fig_light)
-        Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_dark.jpeg"), fig_dark)
-        println(io,
-            """
-            ![]($(filename)_light.jpeg){.light-only}
-            ![]($(filename)_dark.jpeg){.dark-only}
-            """
-        )
-    elseif haskey(d, MIME"image/svg+xml+lightdark"())
-        fig_light, fig_dark, backend = d[MIME"image/svg+lightdark"()]
-        Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_light.svg"), fig_light)
-        Main.Makie.save(joinpath(dirname(page.build), md_output_path, "$(filename)_dark.svg"), fig_dark)
-        println(io,
-            """
-            <img src = "$(filename)_light.svg" style=".light-only"></img>
-            <img src = "$(filename)_dark.svg" style=".dark-only"></img>
-            """
-        )
-    elseif haskey(d, MIME"image/gif"())
-        write(joinpath(dirname(page.build), md_output_path, "$(filename).gif"),
-            base64decode(d[MIME"image/gif"()]))
-        println(io,
-            """
-    ![]($(filename).gif)
-    """)
-    elseif haskey(d, MIME"video/mp4"())
-        write(joinpath(dirname(page.build), md_output_path, "$(filename).gif"),
-            base64decode(d[MIME"image/gif"()]))
-        println(io,
-            """
-    <video src="$filename.mp4" controls="controls" autoplay="autoplay"></video>)
-    """)
-    elseif haskey(d, MIME"text/plain"())
-        text = d[MIME"text/plain"()]
-        out = repr(MIME"text/plain"(), ANSIColoredPrinters.PlainTextPrinter(IOBuffer(text)))
-        render(io, mime, node, Markdown.Code(out), page, doc; kwargs...)
-    else
-        error("this should never happen.")
+    available_mimes = keys(d)
+    if isempty(available_mimes)
+        return nothing
     end
-    return nothing
+    # Sort the available mimes by priority
+    sorted_mimes = sort(collect(available_mimes), by = mime_priority)
+    # Select the best MIME type for rendering
+    best_mime = sorted_mimes[1]
+    # Render the best MIME type
+    render_mime(io, best_mime, node, d[best_mime], page, doc; kwargs...)
 end
 
 ## Basic Nodes. AKA: any other content that hasn't been handled yet.