Create an interface for column components other than MultiDocRef

docs/make.jl

@@ -87,6 +87,10 @@ docs = [
                         name = "JuliaInterpreter",
                         giturl = "https://github.com/JuliaDebug/JuliaInterpreter.jl.git",
                     ),
+                    MultiDocumenter.Link(
+                        "Lux",
+                        "https://github.com/avik-pal/Lux.jl",
+                    ),
                 ],
             ),
             MultiDocumenter.Column(

src/MultiDocumenter.jl

@@ -25,6 +25,23 @@ Base.@kwdef mutable struct SearchConfig
     lowfi = false
 end
 
+"""
+    abstract type DropdownComponent
+
+The supertype for any component that can be put in a dropdown column and 
+rendered using `MultiDocumenter.render(::YourComponent, thispagepath, dir, prettyurls)`.  
+
+All `DropdownComponent`s go in [`Column`](@ref)s, which go in [`MegaDropdownNav`](@ref).
+
+Any subtype of `DropdownComponent` must implement that `render` method.
+
+The main subtype is [`MultiDocRef`](@ref), which refers to external documentation
+and adds it to the search index.  However, there are others like [`ExternalLink`](@ref)
+which is used to link to external sites without making them searchable, and
+users can implement their own custom components.
+"""
+abstract type DropdownComponent end
+
 """
     struct MultiDocRef
 
@@ -44,7 +61,7 @@ Represents one set of docs that will get an entry in the MultiDocumenter navigat
 * `fix_canonical_url`: this can be set to `false` to disable the canonical URL fixing
   for this `MultiDocRef` (see also `canonical_domain` for [`make`](@ref)).
 """
-struct MultiDocRef
+struct MultiDocRef <: DropdownComponent
     upstream::String
     path::String
     name::Any
@@ -64,14 +81,22 @@ function MultiDocRef(;
     MultiDocRef(upstream, path, name, fix_canonical_url, giturl, branch)
 end
 
+
+struct Link <: MultiDocumenter.DropdownComponent
+    text::String
+    link::String
+end
+
+Link(link::String) = Link(link, link)
+
 struct DropdownNav
     name::String
-    children::Vector{MultiDocRef}
+    children::Vector{DropdownComponent}
 end
 
 struct Column
     name::Any
-    children::Vector{MultiDocRef}
+    children::Vector{DropdownComponent}
 end
 
 struct MegaDropdownNav
@@ -84,8 +109,8 @@ struct BrandImage
     imagepath::String
 end
 
-function walk_outputs(f, root, docs::Vector{MultiDocRef}, dirs::Vector{String})
-    for ref in docs
+function walk_outputs(f, root, docs::Vector, dirs::Vector{String})
+    for ref in filter(x -> x isa MultiDocRef, docs)
         p = joinpath(root, ref.path)
         for dir in dirs
             dirpath = joinpath(p, dir)
@@ -256,9 +281,9 @@ function make(
 end
 
 function flatten_multidocrefs(docs::Vector)
-    out = MultiDocRef[]
+    out = DropdownComponent[]
     for doc in docs
-        if doc isa MultiDocRef
+        if doc isa DropdownComponent
             push!(out, doc)
         elseif doc isa MegaDropdownNav
             for col in doc.columns
@@ -272,11 +297,11 @@ function flatten_multidocrefs(docs::Vector)
             end
         end
     end
-    out
+    return out
 end
 
-function maybe_clone(docs::Vector{MultiDocRef})
-    for doc in docs
+function maybe_clone(docs::Vector)
+    for doc in filter(x -> x isa MultiDocRef, docs)
         if !isdir(doc.upstream)
             if isempty(doc.giturl)
                 error(
@@ -311,17 +336,18 @@ function maybe_clone(docs::Vector{MultiDocRef})
             end
         end
     end
+    return nothing
 end
 
 function make_output_structure(
-    docs::Vector{MultiDocRef},
+    docs::Vector,
     prettyurls,
     hide_previews;
     canonical::Union{AbstractString,Nothing},
 )
     dir = mktempdir()
 
-    for doc in docs
+    for doc in Iterators.filter(x -> x isa MultiDocRef, docs)
         outpath = joinpath(dir, doc.path)
 
         mkpath(dirname(outpath))

src/renderers.jl

@@ -36,6 +36,12 @@ function render(doc::MultiDocRef, dir, thispagepath, prettyurls)
     """
 end
 
+function render(c::Link, doc, thispage, prettyurls)
+    return @htl """
+    <a href=$(c.link) class="nav-link nav-item">$(c.text)</a>
+    """ # TODO: add "external link" icon after, either chain or arrow exiting box.
+end
+
 function render(doc::DropdownNav, dir, thispagepath, prettyurls)
     return @htl """
     <div class="nav-dropdown">

test/runtests.jl

@@ -54,6 +54,10 @@ docs = [
                         name = "Lux",
                         giturl = "https://github.com/avik-pal/Lux.jl",
                     ),
+                    MultiDocumenter.Link(
+                        "JuliaHub",
+                        "https://juliahub.com",
+                    ),
                 ],
             ),
             MultiDocumenter.Column(