Merge pull request JuliaPluto#3 from JuliaPluto/IO-Context-passthrough

Project.toml

@@ -1,7 +1,7 @@
 name = "MarkdownLiteral"
 uuid = "736d6165-7244-6769-4267-6b50796e6954"
 authors = ["Fons van der Plas <[email protected]>"]
-version = "0.1.0"
+version = "0.1.1"
 
 [deps]
 CommonMark = "a80b9123-70ca-4bc0-993e-6e3bcb318db6"

src/MarkdownLiteral.jl

@@ -113,12 +113,24 @@ macro markdown(expr)
     ])
     quote
         result = $(esc(Expr(:macrocall, getfield(HypertextLiteral, Symbol("@htl")), __source__, expr)))
-        htl_output = repr(MIME"text/html"(), result)
-
-        $(cm_parser)(htl_output)
+        CMParsedRenderer(contents = result, parser = $cm_parser)
     end
 end
 
+Base.@kwdef struct CMParsedRenderer
+    contents::Any
+    parser::CommonMark.Parser
+end
+
+function Base.show(io::IO, m::MIME"text/html", p::CMParsedRenderer)
+    # Use the given IO as context, render to HTML
+    html_render = sprint(show, m, p.contents; context = io)
+    # Parse the result
+    cm_parsed = p.parser(html_render)
+    # And render to HTML again
+    show(io, m, cm_parsed)
+end
+
 # Some aliases, it's up to you which one to import.
 
 const var"@markdownliteral" = var"@markdown"

test/runtests.jl

@@ -80,4 +80,28 @@ import MarkdownLiteral: @markdown
 
     @test htmle isa String
     @test occursin("Hello", htmle)
+end
+
+@testset "IO Context" begin
+
+    struct Thing end
+
+    function Base.show(io::IO, ::MIME"text/html", ::Thing)
+        write(io, get(io, :hello, "asdf"))
+    end
+
+    h = @markdown("""
+    Hello $(Thing())
+    """)
+
+    s1 = repr(MIME"text/html"(), h)
+    @test s1 isa String
+    @test occursin("Hello", s1)
+    @test occursin("asdf", s1)
+
+    s2 = sprint() do io
+        show(IOContext(io, :hello => "world"), MIME"text/html"(), h)
+    end
+    @test s2 isa String
+    @test occursin("world", s2)
 end