XML document construction

Author: lindahua

src/MiniDOM.jl

@@ -13,9 +13,11 @@ module MiniDOM
 	child_nodes, has_children, attributes, has_attributes, child_elements,
 	find_element, get_elements_by_tagname,
 
+	new_node, add_child, new_child, add_text, set_attribute,
+
 	# document
-	XMLDocument, version, encoding, compression, standalone, docelement, 
-	parse_file, parse_string, save_file
+	XMLDocument, version, encoding, compression, standalone, root, 
+	parse_file, parse_string, save_file, set_root, create_root
 
 
 	include("clib.jl")

src/clib.jl

@@ -44,9 +44,16 @@ _xcopystr(p::Xstr) = (r = bytestring(p); _xmlfree(p); r)
 @lx2func xmlNextElementSibling
 @lx2func xmlNodeDump
 
+@lx2func xmlNewNode
+@lx2func xmlAddChild
+@lx2func xmlNewText
+@lx2func xmlSetProp
+
 # functions for documents
 
 @lx2func xmlDocGetRootElement
+@lx2func xmlDocSetRootElement
+@lx2func xmlNewDoc
 @lx2func xmlFreeDoc
 @lx2func xmlParseFile
 @lx2func xmlParseMemory

src/document.jl

@@ -45,14 +45,20 @@ type XMLDocument
 
 		new(ptr, s)
 	end
+
+	function XMLDocument()
+		# create an empty document
+		ptr = ccall(xmlNewDoc, Xptr, (Ptr{Cchar},), "1.0")
+		XMLDocument(ptr)	
+	end
 end
 
 version(xdoc::XMLDocument) = bytestring(xdoc._struct.version)
 encoding(xdoc::XMLDocument) = bytestring(xdoc._struct.encoding)
 compression(xdoc::XMLDocument) = int(xdoc._struct.compression)
 standalone(xdoc::XMLDocument) = int(xdoc._struct.standalone)
 
-function docelement(xdoc::XMLDocument)
+function root(xdoc::XMLDocument)
 	pr = ccall(xmlDocGetRootElement, Ptr{Void}, (Ptr{Void},), xdoc.ptr)
 	pr != nullptr || throw(XMLNoRootError())
 	XMLElement(pr)
@@ -66,6 +72,15 @@ function free(xdoc::XMLDocument)
 	xdoc.ptr = nullptr
 end
 
+function set_root(xdoc::XMLDocument, xroot::XMLElement)
+	ccall(xmlDocSetRootElement, Xptr, (Xptr, Xptr), xdoc.ptr, xroot.node.ptr)
+end
+
+function create_root(xdoc::XMLDocument, name::ASCIIString)
+	xroot = new_element(name)
+	set_root(xdoc, xroot)
+	return xroot
+end
 
 #### parse and free
 

src/errors.jl

@@ -15,6 +15,10 @@ immutable XMLWriteError <: XMLError
 	msg::ASCIIString
 end
 
+immutable XMLTreeError <: XMLError
+	msg::ASCIIString
+end
+
 const dom_exception_causes = [
 	"Index size error",        #  1
 	"DOM string size error",   #  2

src/nodes.jl

@@ -249,3 +249,41 @@ function get_elements_by_tagname(x::XMLElement, n::ASCIIString)
 	return lst
 end
 
+
+#######################################
+#
+#  XML Tree Construction
+#
+#######################################
+
+function new_element(name::ASCIIString)
+	p = ccall(xmlNewNode, Xptr, (Xptr, Xstr), nullptr, name)
+	XMLElement(p)
+end
+
+function add_child(xparent::XMLElement, xchild::XMLNode)
+	p = ccall(xmlAddChild, Xptr, (Xptr, Xptr), xparent.node.ptr, xchild.ptr)
+	p != nullptr || throw(XMLTreeError("Failed to add a child node."))
+end
+
+add_child(xparent::XMLElement, xchild::XMLElement) = add_child(xparent, xchild.node)
+
+function new_child(xparent::XMLElement, name::ASCIIString)
+	xc = new_element(name)
+	add_child(xparent, xc)
+	return xc
+end
+
+function new_textnode(txt::ASCIIString)
+	p = ccall(xmlNewText, Xptr, (Xstr,), txt)
+	XMLNode(p)
+end
+
+add_text(x::XMLElement, txt::ASCIIString) = add_child(x, new_textnode(txt))
+
+function set_attribute(x::XMLElement, name::ASCIIString, val::ASCIIString)
+	a = ccall(xmlSetProp, Xptr, (Xptr, Xstr, Xstr), x.node.ptr, name, val)
+	return XMLAttr(a)
+end
+
+

test/create.jl

@@ -0,0 +1,15 @@
+using MiniDOM
+
+xdoc = XMLDocument()
+
+xroot = create_root(xdoc, "States")
+
+xs1 = new_child(xroot, "State")
+add_text(xs1, "Massachusetts")
+set_attribute(xs1, "tag", "MA")
+
+xs2 = new_child(xroot, "State")
+add_text(xs2, "Illinois")
+set_attribute(xs2, "tag", "MA")
+
+show(xdoc)

test/dump.jl

@@ -30,7 +30,7 @@ show(xdoc)
 
 println("Root Element:")
 println("=====================")
-xroot = docelement(xdoc)
+xroot = root(xdoc)
 show(xroot)
 
 free(xdoc)

test/parse.jl

@@ -30,7 +30,7 @@ xdoc = parse_string(docstr)
 
 # root node
 
-xroot = docelement(xdoc)
+xroot = root(xdoc)
 
 @test isa(xroot, XMLElement)
 @test is_elementnode(xroot)