improving HTML to permit nesting

[clarkevans]

Is there anyway the following two lines could be added to base/docs/utils.jl for this upcoming 1.6?

print(io::IO, h::HTML) = print(io, h.content)
print(io::IO, h::HTML{<:Function}) = h.content(io)

This feature provides two benefits. First, it lets HTML objects nest arbitrarily deep (eliminating need for catdoc?). Second it lets the user use print(h) in addition to display("text/html", h). Following is a walk-though of usability before/after the change.

# HTML has 2 constructors, list all 4 permutations

julia> h1 = HTML(HTML("<tag/>"))
HTML{HTML{String}}(HTML{String}("<tag/>"))

julia> h2 = HTML("<div>", HTML("<span>text</span>"), "</div>")
HTML{Base.Docs.var"#9#10"{Tuple{String,HTML{String},String}}}(Base.Docs.var"#9#10"{Tuple{String,HTML{String},String}}(("<div>", HTML{String}("<span>text</span"), "</div>")))

julia> h3 = HTML(HTML("<span>", "text", "</span>"))
HTML{HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}}}(HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}}(Base.Docs.var"#9#10"{Tuple{String,String,String}}(("<span>", "text", "</span"))))

julia> h4 = HTML("<div>", HTML("<span>", "text", "</span>"), "</div>")
HTML{Base.Docs.var"#9#10"{Tuple{String,HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}},String}}}(Base.Docs.var"#9#10"{Tuple{String,HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}},String}}(("<div>", HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}}(Base.Docs.var"#9#10"{Tuple{String,String,String}}(("<span>", "text", "</span"))), "</div>")))

# Existing, unusuable display

julia> display("text/html", h1)
HTML{String}("<tag/>")

julia> display("text/html", h2)
HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}}(Base.Docs.var"#9#10"{Tuple{String,String,String}}(("<span>", "text", "</span>")))

julia> display("text/html", h3)
HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}}(Base.Docs.var"#9#10"{Tuple{String,String,String}}(("<span>", "text", "</span>")))

julia> display("text/html", h4)
<div>HTML{Base.Docs.var"#9#10"{Tuple{String,String,String}}}(Base.Docs.var"#9#10"{Tuple{String,String,String}}(("<span>", "text", "</span>")))</div>

# Apply the two new functions...

julia> Base.print(io::IO, h::HTML) = print(io, h.content)
julia> Base.print(io::IO, h::HTML{<:Function}) = h.content(io)

# Then we get usable, expected output via nesting

julia> display("text/html", h1)
<tag/>

julia> display("text/html", h2)
<div><span>text</span></div>

julia> display("text/html", h3)
<span>text</span>

julia> display("text/html", h4)
<div><span>text</span></div>

This comes out of work on HypertextLiteral.jl and I've had to create my own HTML like object that differs only since it has this additional 2 statements. I don't see any side effects and it provides excellent value that would be great to have in a LTS, since so much new work involves building web services in Julia.

[clarkevans]

How do I just test one of the test files? My computer isn't powerful enough to run though all the tests in less than an hour or two.

[mgkuhn]

How do I just test one of the test files?

make -C test version

or

cd test && make version

will only run e.g. test/version.jl.

[musm]

Closing this as HTML was never meant to be a user-facing API.