Initialize global variables lazily instead of during precompilation. (#…

…914)

src/build.jl

@@ -1,4 +1,4 @@
-const PY = begin
+function PY()
     if "PYTHON3" ∈ keys(ENV)
         ENV["PYTHON3"]
     else
@@ -9,7 +9,7 @@ const PY = begin
         end
     end
 end
-const PIP = begin
+function PIP()
     if "PIP3" ∈ keys(ENV)
         ENV["PIP3"]
     else
@@ -20,7 +20,7 @@ const PIP = begin
         end
     end
 end
-const NODE = begin
+function NODE()
     if "NODE" ∈ keys(ENV)
         ENV["NODE"]
     else
@@ -39,44 +39,55 @@ Pre-rendering
 require `katex.min.js`
 - For highlights, we need `node` and also to have the `highlight.js` installed via `npm`.
 =#
-const FD_CAN_PRERENDER = shell_try(`$NODE -v`)
-const FD_CAN_HIGHLIGHT = shell_try(`$NODE -e "require('$(HIGHLIGHTJS[])')"`)
+function FD_CAN_PRERENDER()
+    r = shell_try(`$(NODE()) -v`)
+    if !r
+        @warn """Couldn't find node.js: `$(NODE()) -v` failed. Setting `prerender=false`.
+
+        Note: node is required for pre-rendering KaTeX and highlight.js, but it is not necessary to run Franklin (cf docs)."""
+    end
+    return r
+end
+let r = nothing # Hack to only run the checks once per call to Franklin.optimize since this is called multiple times
+    global function FD_CAN_HIGHLIGHT(; force::Bool=false)
+        if force || r === nothing
+            r = FD_CAN_PRERENDER() && shell_try(`$(NODE()) -e "require('$(HIGHLIGHTJS[])')"`)
+            if !r
+                @warn """Couldn't find highlight.js: `$(NODE()) -e "require('$(HIGHLIGHTJS[])')"` failed. Will not prerender code blocks.
+
+                Note: highlight.js is required for pre-rendering highlight.js, but is not necessary to run Franklin (cf docs)."""
+            end
+        end
+        return r
+    end
+end
 
 #=
 Minification
 - We use `css_html_js_minify`. To use it, you need python3 and to install it.
 - Here we check there is python3, and pip3, and then if we fail to import, we try to
 use pip3 to install it.
 =#
-const FD_HAS_PY3    = shell_try(`$([e for e in split(PY)]) -V`)
-const FD_HAS_PIP3   = shell_try(`$([e for e in split(PIP)]) -V`)
-const FD_CAN_MINIFY = FD_HAS_PY3 && FD_HAS_PIP3 &&
-        (success(`$([e for e in split(PY)]) -c "import css_html_js_minify"`) ||
-         success(`$([e for e in split(PIP)]) install css_html_js_minify`))
-#=
-Information to the user
-- what Franklin couldn't find
-- that the user should do a `build` step after installing
-=#
-FD_CAN_HIGHLIGHT || begin
-    FD_CAN_PRERENDER || begin
-        println("""✘ Couldn't find node.js (`$NODE -v` failed).
-                → It is required for pre-rendering KaTeX and highlight.js but is not necessary to run Franklin (cf docs).""")
-    end
-    println("""✘ Couldn't find highlight.js (`$NODE -e "require('$(HIGHLIGHTJS[])')"` failed).
-            → It is required for pre-rendering highlight.js but is not necessary to run Franklin (cf docs).""")
-end
+function FD_HAS_PY3()
+    r = shell_try(`$([e for e in split(PY())]) -V`)
+    if !r
+        @warn """Couldn't find python3 (`$([e for e in split(PY())]) -V` failed). Will not minify.
 
-FD_CAN_MINIFY || begin
-    if FD_HAS_PY3
-        println("✘ Couldn't find css_html_js_minify (`$([e for e in split(PY)]) -m \"import css_html_js_minify\"` failed).\n" *
-                """→ It is required for minification but is not necessary to run Franklin (cf docs).""")
-    else
-        println("""✘ Couldn't find python3 (`$([e for e in split(PY)]) -V` failed).
-                → It is required for minification but not necessary to run Franklin (cf docs).""")
+        Note: python3 is required for minification, but not necessary to run Franklin (cf docs)."""
     end
+    return r
 end
+FD_HAS_PIP3() = shell_try(`$([e for e in split(PIP())]) -V`)
+
+function FD_CAN_MINIFY()
+    r = FD_HAS_PY3() && FD_HAS_PIP3()
+    r || return r
+    r = (success(`$([e for e in split(PY())]) -c "import css_html_js_minify"`) ||
+         success(`$([e for e in split(PIP())]) install css_html_js_minify`))
+    if !r
+        @warn """Couldn't find css_html_js_minify (`$([e for e in split(PY())]) -m "import css_html_js_minify"` failed). Will not minify.
 
-all((FD_CAN_HIGHLIGHT, FD_CAN_PRERENDER, FD_CAN_MINIFY, FD_HAS_PY3, FD_HAS_PIP3)) || begin
-    println("→ After installing any missing component, please re-build the package (cf docs).")
+        Note: css_html_js_minify is required for minification, but is not necessary to run Franklin (cf docs)."""
+    end
+    return r
 end

src/converter/html/prerender.jl

@@ -85,7 +85,7 @@ function js2html(hs::String, jsbuffer::IOBuffer, matches::Vector{RegexMatch},
                  splitter::String)::String
     # run it redirecting the output to a buffer
     outbuffer = IOBuffer()
-    run(pipeline(`$NODE -e "$(String(take!(jsbuffer)))"`, stdout=outbuffer))
+    run(pipeline(`$(NODE()) -e "$(String(take!(jsbuffer)))"`, stdout=outbuffer))
 
     # read the buffer and split it using $splitter
     out = String(take!(outbuffer))

src/manager/extras.jl

@@ -27,7 +27,7 @@ function lunr()::Nothing
         start = time()
         msg   = rpad("→ Building the Lunr index...", 35)
         print(msg)
-        run(`$NODE $(splitdir(buildindex)[2])`)
+        run(`$(NODE()) $(splitdir(buildindex)[2])`)
         print_final(msg, start)
     catch e
         @warn "There was an error building the Lunr index."

src/manager/post_processing.jl

@@ -57,14 +57,10 @@ function optimize(;
     #
     # Prerendering
     #
-    if prerender && !FD_CAN_PRERENDER
-        @warn "I couldn't find node and so will not be able to pre-render javascript."
+    if prerender && !FD_CAN_PRERENDER(; force=true)
         prerender = false
     end
-    if prerender && !FD_CAN_HIGHLIGHT
-        @warn "I couldn't load 'highlight.js' so will not be able to pre-render code blocks. " *
-              "You can install it with `npm install highlight.js`."
-    end
+    prerender && !FD_CAN_HIGHLIGHT(; force=true)
     if !isempty(prepath)
         GLOBAL_VARS["prepath"] = dpair(prepath)
     end
@@ -104,7 +100,7 @@ function optimize(;
     # Minification
     #
     if minify && (succ || no_fail_prerender)
-        if FD_CAN_MINIFY
+        if FD_CAN_MINIFY()
             start = time()
             mmsg = rpad("→ Minifying *.[html|css] files...", 35)
             print(mmsg)
@@ -114,13 +110,10 @@ function optimize(;
             py_script = read(path_to, String)
             write(FD_PY_MIN_NAME, py_script)
             # run it
-            succ = success(`$([e for e in split(PY)]) $FD_PY_MIN_NAME`)
+            succ = success(`$([e for e in split(PY())]) $FD_PY_MIN_NAME`)
             # remove the script file
             rm(FD_PY_MIN_NAME)
             print_final(mmsg, start)
-        else
-            @warn "I didn't find css_html_js_minify, you can install it via " *
-                  "pip. The output will not be minified."
         end
     end
 

src/manager/write_page.jl

@@ -46,7 +46,7 @@ function postprocess_page(pg)
             pg = js_prerender_katex(pg)
         end
         # Code (HIGHLIGHT.JS)
-        if locvar(:hascode)::Bool && FD_CAN_HIGHLIGHT
+        if locvar(:hascode)::Bool && FD_CAN_HIGHLIGHT()
             pg = js_prerender_highlight(pg)
             # remove script
             pg = replace(pg, r"<script.*?(?:highlight\.pack\.js|initHighlightingOnLoad).*?<\/script>"=>"")

test/global/postprocess.jl

@@ -24,7 +24,7 @@
     @test isfile(joinpath("__site", "css", "franklin.css"))
 
     # ---------------
-    if Franklin.FD_CAN_MINIFY
+    if Franklin.FD_CAN_MINIFY()
         presize1 = stat(joinpath("__site", "css", "basic.css")).size
         presize2 = stat(joinpath("__site", "index.html")).size
         optimize(prerender=false)
@@ -51,7 +51,7 @@
     @test occursin("=\"/prependme/libs/katex/katex.min.css", index)
 end
 
-if F.FD_CAN_PRERENDER; @testset "prerender" begin
+if F.FD_CAN_PRERENDER(); @testset "prerender" begin
     @testset "katex" begin
         hs = raw"""
         <!doctype html>
@@ -73,7 +73,7 @@ if F.FD_CAN_PRERENDER; @testset "prerender" begin
         # @test occursin("""<span class=\"katex-display\"><span class=\"katex\"><span class=\"katex-mathml\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><semantics><mrow><mi>M</mi>""", jskx)
     end
 
-    if F.FD_CAN_HIGHLIGHT; @testset "highlight" begin
+    if F.FD_CAN_HIGHLIGHT(); @testset "highlight" begin
         hs = raw"""
         <!doctype html>
         <html lang=en>