Amend XML.write to respect xml:space="preserve"

src/XML.jl

@@ -149,8 +149,8 @@ end
 function Node(o::Node, x...; kw...)
     attrs = !isnothing(kw) ?
         merge(
-            OrderedDict(string(k) => string(v) for (k,v) in pairs(kw)),
-            isnothing(o.attributes) ? OrderedDict{String, String}() : o.attributes
+            OrderedDict(string(k) => string(v) for (k, v) in pairs(kw)),
+            isnothing(o.attributes) ? OrderedDict{String,String}() : o.attributes
         ) :
         o.attributes
     children = isempty(x) ? o.children : vcat(isnothing(o.children) ? [] : o.children, collect(x))
@@ -357,56 +357,69 @@ write(x; kw...) = (io = IOBuffer(); write(io, x; kw...); String(take!(io)))
 
 write(filename::AbstractString, x; kw...) = open(io -> write(io, x; kw...), filename, "w")
 
-function write(io::IO, x; indentsize::Int=2, depth::Int=1)
+function write(io::IO, x, ctx::Vector{Bool}=[false]; indentsize::Int=2, depth::Int=1)
     indent = ' ' ^ indentsize
     nodetype = XML.nodetype(x)
     tag = XML.tag(x)
     value = XML.value(x)
     children = XML.children(x)
 
     padding = indent ^ max(0, depth - 1)
-    print(io, padding)
+    !ctx[end] && print(io, padding)
+
     if nodetype === Text
         print(io, value)
+
     elseif nodetype === Element
+        push!(ctx, ctx[end])
+        update_ctx!(ctx, x)
         print(io, '<', tag)
         _print_attrs(io, x)
         print(io, isempty(children) ? '/' : "", '>')
         if !isempty(children)
             if length(children) == 1 && XML.nodetype(only(children)) === Text
-                write(io, only(children); indentsize=0)
+                write(io, only(children), ctx; indentsize=0)
                 print(io, "</", tag, '>')
             else
-                println(io)
+                !ctx[end] && println(io)
                 foreach(children) do child
-                    write(io, child; indentsize, depth = depth + 1)
-                    println(io)
+                    write(io, child, ctx; indentsize, depth=depth + 1)
+                    !ctx[end] && println(io)
                 end
-                print(io, padding, "</", tag, '>')
+                print(io, !ctx[end] ? padding : "", "</", tag, '>')
             end
         end
+        pop!(ctx)
+
     elseif nodetype === DTD
         print(io, "<!DOCTYPE ", value, '>')
+
     elseif nodetype === Declaration
         print(io, "<?xml")
         _print_attrs(io, x)
         print(io, "?>")
+
     elseif nodetype === ProcessingInstruction
         print(io, "<?", tag)
         _print_attrs(io, x)
         print(io, "?>")
+
     elseif nodetype === Comment
         print(io, "<!--", value, "-->")
+
     elseif nodetype === CData
         print(io, "<![CData[", value, "]]>")
+
     elseif nodetype === Document
         foreach(children) do child
-            write(io, child; indentsize)
-            println(io)
+            write(io, child, ctx; indentsize)
+            !ctx[end] && println(io)
         end
+
     else
         error("Unreachable case reached during XML.write")
     end
-end
 
 end
+
+end # module XML

src/raw.jl

@@ -146,7 +146,6 @@ function get_attributes(data, i, j)
     out = OrderedDict{String,String}()
     while !isnothing(i) && i < j
         key, i = get_name(data, i)
-        #haskey(out, key) && error("Duplicate attribute name found: $key") # would this be useful?
         # get quotechar the value is wrapped in (either ' or ")
         i = findnext(x -> x === UInt8('"') || x === UInt8('''), data, i + 1)
         quotechar = data[i]
@@ -329,7 +328,11 @@ function parent(o::Raw)
 end
 
 #-----------------------------------------------------------------------------# next Raw
-isspace(x::UInt8) = Base.isspace(Char(x))
+# isspace(x::UInt8) = Base.isspace(Char(x))
+
+# XML whitespace per XML 1.0/1.1 production S:
+#   S ::= (#x20 | #x9 | #xD | #xA)+
+@inline xml_isspace(b::UInt8)::Bool = (b == 0x20) | (b == 0x09) | (b == 0x0A) | (b == 0x0D)
 
 """
     next(node) --> typeof(node) or Nothing
@@ -353,7 +356,7 @@ function next_xml_space(o::Raw)
     has_xml_space = o.has_xml_space
     ctx = copy(o.ctx)
     last_type = type
-    k = findnext(!isspace, data, i)
+    k = findnext(!xml_isspace, data, i)
     if isnothing(k)
         return nothing
     end
@@ -369,11 +372,11 @@ function next_xml_space(o::Raw)
     if c !== '<' || ctx[end] && c === '<' && b === ' ' && last_type === RawElementOpen && d === '/'
         type = RawText
         j = findnext(==(UInt8('<')), data, i) - 1
-        j = ctx[end] ? j : findprev(!isspace, data, j) # preserving whitespace if needed
+        j = ctx[end] ? j : findprev(!xml_isspace, data, j) # preserving whitespace if needed
         if last_type === RawElementClose || last_type === RawElementSelfClosed|| last_type === RawDocument
             # Maybe drop pure-whitespace inter-element text nodes?
             # (e.g. whitespace between a closing and an opening tag which would otherwise make an orphan text node)
-            #if all(isspace, @view data[i:j]) && depth > 1
+            #if all(xml_isspace, @view data[i:j]) && depth > 1
             #    return next(Raw(type, depth, j, 0, data, ctx, has_xml_space))
             #end
         end
@@ -421,15 +424,15 @@ function next_xml_space(o::Raw)
     end
     return Raw(type, depth, i, j - i, data, ctx, has_xml_space)
 end
-#
+
 function next_no_xml_space(o::Raw) # same as v0.3.5
     i = o.pos + o.len + 1
     depth = o.depth
     data = o.data
     type = o.type
     has_xml_space = o.has_xml_space
     ctx = [false]
-    i = findnext(!isspace, data, i)
+    i = findnext(!xml_isspace, data, i)
     if isnothing(i)
         return nothing
     end
@@ -441,7 +444,7 @@ function next_no_xml_space(o::Raw) # same as v0.3.5
     if c !== '<'
         type = RawText
         j = findnext(==(UInt8('<')), data, i) - 1
-        j = findprev(!isspace, data, j)   # "rstrip"
+        j = findprev(!xml_isspace, data, j)   # "rstrip"
     elseif c === '<'
         c2 = Char(o.data[i+1])
         if c2 === '!'
@@ -514,7 +517,7 @@ function prev_no_xml_space(o::Raw) # same as v0.3.5
     ctx = has_xml_space ? copy(o.ctx) : [false]
     type === RawDocument && return nothing
     j = o.pos - 1
-    j = findprev(!isspace, data, j)
+    j = findprev(!xml_isspace, data, j)
     if isnothing(j)
         return Raw(data, has_xml_space, ctx)  # RawDocument
     end
@@ -523,7 +526,7 @@ function prev_no_xml_space(o::Raw) # same as v0.3.5
     if c !== '>' # text
         type = RawText
         i = findprev(==(UInt8('>')), data, j) + 1
-        i = findnext(!isspace, data, i)  # "lstrip"
+        i = findnext(!xml_isspace, data, i)  # "lstrip"
     elseif c === '>'
         c2 = Char(o.data[j-1])
         if c2 === '-'
@@ -562,3 +565,4 @@ function prev_no_xml_space(o::Raw) # same as v0.3.5
     end
     return Raw(type, depth, i, j - i, data, ctx, has_xml_space)
 end
+

test/runtests.jl

@@ -147,13 +147,13 @@ end
         @test text_content == "hello"
         n=XML.next(n)
         text_content = XML.write(n)
-        @test text_content == "<text3 xml:space=\"preserve\">\n    hello  \n  <text3b>  preserve  </text3b>\n</text3>"
+        @test text_content == "<text3 xml:space=\"preserve\">  hello  <text3b>  preserve  </text3b></text3>"
         n=XML.prev(n)
         text_content = XML.write(n)
         @test text_content == "hello"
         n=XML.next(n)
         text_content = XML.write(n)
-        @test text_content == "<text3 xml:space=\"preserve\">\n    hello  \n  <text3b>  preserve  </text3b>\n</text3>"
+        @test text_content == "<text3 xml:space=\"preserve\">  hello  <text3b>  preserve  </text3b></text3>"
         n=XML.next(n)
         text_content = XML.write(n)
         @test text_content == "  hello  "
@@ -183,13 +183,13 @@ end
         @test text_content == "  hello  "
         n=XML.prev(n)
         text_content = XML.write(n)
-        @test text_content == "<text3 xml:space=\"preserve\">\n    hello  \n  <text3b>  preserve  </text3b>\n</text3>"
+        @test text_content == "<text3 xml:space=\"preserve\">  hello  <text3b>  preserve  </text3b></text3>"
         n=XML.next(n)
         text_content = XML.write(n)
         @test text_content == "  hello  "
         n=XML.prev(n)
         text_content = XML.write(n)
-        @test text_content == "<text3 xml:space=\"preserve\">\n    hello  \n  <text3b>  preserve  </text3b>\n</text3>"
+        @test text_content == "<text3 xml:space=\"preserve\">  hello  <text3b>  preserve  </text3b></text3>"
         n=XML.prev(n)
         text_content = XML.write(n)
         @test text_content == "hello"
@@ -201,7 +201,7 @@ end
         @test text_content == "<text/>"
         n=XML.prev(n)
         text_content = XML.write(n)
-        @test text_content == "<root>\n  <text/>\n  <text2>hello</text2>\n  <text3 xml:space=\"preserve\">\n      hello  \n    <text3b>  preserve  </text3b>\n  </text3>\n  <text4 xml:space=\"preserve\"/>\n  <text5/>\n</root>"
+        @test text_content == "<root>\n  <text/>\n  <text2>hello</text2>\n  <text3 xml:space=\"preserve\">  hello  <text3b>  preserve  </text3b></text3>\n  <text4 xml:space=\"preserve\"/>\n  <text5/>\n</root>"
     end
 
     @testset "depth and parent" begin
@@ -428,19 +428,18 @@ end
         @test XML.value(d2[1][6][1]) == "  after default gap  "
         @test XML.value(d2[1][7]) == "\n"
     end
-
-#    @testset "XML whitespace vs Unicode whitespace" begin
-#        nbsp = "\u00A0"
-#        s = """<root>
-#                 <a>  x\t\n  </a>
-#                 <b>$(nbsp) y $(nbsp)</b>
-#                 <c xml:space="default">$(nbsp)  z  $(nbsp)</c>
-#               </root>"""
-#        d = XML.parse(XML.Node, s)
-#        @test XML.value(d[1][1][1]) == "x"
-#        @test XML.value(d[1][2][1]) == "$(nbsp) y $(nbsp)"
-#        @test XML.value(d[1][3][1]) == "$(nbsp)  z  $(nbsp)"
-#    end
+    @testset "XML whitespace vs Unicode whitespace" begin
+        nbsp = "\u00A0"
+        s = """<root>
+                 <a>  x\t\n  </a>
+                 <b>$(nbsp) y $(nbsp)</b>
+                 <c xml:space="default">$(nbsp)  z  $(nbsp)</c>
+               </root>"""
+        d = XML.parse(XML.Node, s)
+        @test XML.value(d[1][1][1]) == "x"
+        @test XML.value(d[1][2][1]) == "$(nbsp) y $(nbsp)"
+        @test XML.value(d[1][3][1]) == "$(nbsp)  z  $(nbsp)"
+    end
 
     @testset "CDATA/Comment/PI boundaries" begin
         s = """<root>
@@ -485,17 +484,21 @@ end
         @test XML.value(d[1][1]) == "a"
     end
 
-#    @testset "entities expanding to whitespace" begin
-#        s = """<root>
-#                 <a> &#x20; a &#x0A; </a>
-#                 <b xml:space="preserve">&#x20; b &#x0A;</b>
-#                 <c>&#xA0;c&#xA0;</c>
-#               </root>"""
-#        d = XML.parse(XML.Node, s)
-#        @test XML.value(d[1][1][1]) == "a"
-#        @test XML.value(d[1][2][1]) == "  b \n"
-#        @test XML.value(d[1][3][1]) == "\u00A0c\u00A0"
-#    end
+    @testset "entities expanding to whitespace" begin
+        chr1="\u0020"
+        chr2="\u000A"
+        chr3="\u00A0"
+
+        s = """<root>
+                 <a> $(chr1) a $(chr2) </a>
+                 <b xml:space="preserve">$(chr1) b $(chr2)</b>
+                 <c>$(chr3)c$(chr3)</c>
+               </root>"""
+        d = XML.parse(XML.Node, s)
+        @test XML.value(d[1][1][1]) == "a"
+        @test XML.value(d[1][2][1]) == "  b \n"
+        @test XML.value(d[1][3][1]) == "$(chr3)c$(chr3)"
+    end
 
     @testset "invalid values and placement" begin
         s_bad = """<root><x xml:space="weird"> t </x></root>"""
@@ -534,23 +537,22 @@ end
         @test reverse(back)[2:end] == toks[1:end-1]
     end
 
-#    @testset "write/read roundtrip extremes" begin
-    # XML.write doesn't respect xml:space="preserve" in the current implementation so roundtrip isn't possible.
-#        xml = """<root>
-#                   <p xml:space="preserve">    </p>
-#                   <q>   </q>
-#                   <r xml:space="default">  r  </r>
-#                   <s xml:space="preserve"> pre <t/> post </s>
-#                 </root>"""
-#        n = XML.parse(XML.Node, xml)
-#        io = IOBuffer(); XML.write(io, n)
-#        n2 = XML.parse(XML.Node, String(take!(io)))
-#        @test n == n2
-#        @test XML.write(n2[1][1]) == "<p xml:space=\"preserve\">    </p>"
-#        @test XML.write(n2[1][2]) == "<q/>"
-#        @test XML.value(n2[1][3][1]) == "r"
-#        @test XML.write(n2[1][4]) == "<s xml:space=\"preserve\"> pre <t/> post </s>"
-#   end
+    @testset "write/read roundtrip extremes" begin
+        xml = """<root>
+                   <p xml:space="preserve">    </p>
+                   <q>   </q>
+                   <r xml:space="default">  r  </r>
+                   <s xml:space="preserve"> pre <t/> post </s>
+                 </root>"""
+        n = XML.parse(XML.Node, xml)
+        io = IOBuffer(); XML.write(io, n)
+        n2 = XML.parse(XML.Node, String(take!(io)))
+        @test n == n2
+        @test XML.write(n2[1][1]) == "<p xml:space=\"preserve\">    </p>"
+        @test XML.write(n2[1][2]) == "<q/>"
+        @test XML.value(n2[1][3][1]) == "r"
+        @test XML.write(n2[1][4]) == "<s xml:space=\"preserve\"> pre <t/> post </s>"
+   end
 
     @testset "self-closing/empty/whitespace-only children" begin
         s = """<root>
@@ -641,3 +643,4 @@ end
     xyz  = XML.Element("point"; kw...)
     @test collect(keys(attributes(xyz))) == string.(collect('a':'z'))
 end
+