fixing isempty hfun

Project.toml

@@ -1,7 +1,7 @@
 name = "Franklin"
 uuid = "713c75ef-9fc9-4b05-94a9-213340da978e"
 authors = ["Thibaut Lienart <[email protected]>"]
-version = "0.10.53"
+version = "0.10.54"
 
 [deps]
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"

docs/syntax/page-variables.md

@@ -173,7 +173,7 @@ You can also use some dedicated conditional blocks:
 | `{{isnotpage path/to/page}}` | opposite of previous
 | `{{isdef vname}}` | whether `vname` is defined
 | `{{isnotdef vname}}` | opposite of previous
-| `{{isempty vname}}`| whether `vname` is empty
+| `{{isempty vname}}`| whether `vname` is nothing, empty, or if a date `0001-01-01`
 | `{{isnotempty vname}}`| opposite of previous
 @@
 

src/converter/html/blocks.jl

@@ -68,7 +68,7 @@ function process_html_cond(hs::AS, qblocks::Vector{AbstractBlock},
                 k ⊻= βi isa HIsNotDef
             elseif βi isa Union{HIsEmpty, HIsNotEmpty}
                 v = locvar(βi.vname)
-                e = isnothing(v) || isempty(v)
+                e = _isempty(v)
                 k = ifelse(βi isa HIsEmpty, e, !e)
             end
         else
@@ -154,6 +154,12 @@ function process_html_cond(hs::AS, qblocks::Vector{AbstractBlock},
     return content, head, i_close
 end
 
+# used for the HIsEmpty, HIsNotEmpty
+_isempty(v::T) where T = hasmethod(isempty, (T,)) ? isempty(v) : false
+_isempty(::Nothing)    = true
+_isempty(v::Date)      = (v == Date(1,1,1))
+
+
 """
 $SIGNATURES
 

test/converter/html/html_functions.jl

@@ -18,3 +18,16 @@ end
     # must end with html
     @test_throws F.HTMLFunctionError ("{{redirect foo}}" |> fd2html)
 end
+
+@testset "isempty" begin
+    s = """
+        +++
+        using Dates
+        d = Date(1,1,1)
+        x = nothing
+        +++
+        {{isempty d}}A{{end}}
+        {{isempty x}}B{{end}}
+        """ |> fd2html_td
+    @test isapproxstr(s, "<p>AB</p>")
+end