DOM

src/dlangui/core/dom.d

@@ -4,7 +4,19 @@ import dlangui.core.collections;
 
 import std.traits;
 import std.conv : to;
-import std.string;
+import std.string : startsWith, endsWith;
+import std.array : empty;
+import std.algorithm : equal;
+
+// Namespace, element tag and attribute names are stored as numeric ids for better performance and lesser memory consumption.
+
+/// id type for interning namespaces
+alias ns_id = ushort;
+/// id type for interning element names
+alias elem_id = uint;
+/// id type for interning attribute names
+alias attr_id = ushort;
+
 
 /// Base class for DOM nodes
 class Node {
@@ -17,6 +29,15 @@ public:
     /// returns document node
     @property Document document() { return _document; }
 
+    /// return element tag id
+    @property elem_id id() { return 0; }
+    /// return element namespace id
+    @property ns_id nsid() { return 0; }
+    /// return element tag name
+    @property string name() { return document.tagName(id); }
+    /// return element namespace name
+    @property string nsname() { return document.nsName(nsid); }
+
     // node properties
 
     /// returns true if node is text
@@ -42,6 +63,18 @@ public:
     /// returns last child node
     @property Node lastChild() { return null; }
 
+    /// find child node, return its index if found, -1 if not found or not child of this node
+    int childIndex(Node child) { return -1; }
+    /// return node index in parent's child node collection, -1 if not found
+    @property int index() { return _parent ? _parent.childIndex(this) : -1; }
+
+    /// append text child
+    Node appendText(dstring s, int index = -1) { assert(false); }
+    /// append element child - by namespace and tag names
+    Node appendElement(string ns, string tag, int index = -1) { assert(false); }
+    /// append element child - by namespace and tag ids
+    Node appendElement(ns_id ns, elem_id tag, int index = -1) { assert(false); }
+
     /// node text
     @property dstring text() { return null; }
     /// ditto
@@ -54,7 +87,10 @@ public:
 class Text : Node {
 private:
     dstring _text;
-
+    this(Document doc, dstring text = null) {
+        _document = doc;
+        _text = text;
+    }
 public:
     /// node text
     override @property dstring text() { return _text; }
@@ -66,7 +102,21 @@ public:
 class Element : Node {
 private:
     Collection!Node _children;
+    elem_id _id; // element tag id
+    ns_id _ns; // element namespace id
+
+    this(Document doc, ns_id ns, elem_id id) {
+        _document = doc;
+        _ns = ns;
+        _id = id;
+    }
 public:
+
+    /// return element tag id
+    override @property elem_id id() { return _id; }
+    /// return element namespace id
+    override @property ns_id nsid() { return _ns; }
+
     // child nodes
 
     /// returns child node count
@@ -77,15 +127,88 @@ public:
     override @property Node firstChild() { return _children.length > 0 ? _children[0] : null; }
     /// returns last child node
     override @property Node lastChild() { return _children.length > 0 ? _children[_children.length - 1] : null; }
+    /// find child node, return its index if found, -1 if not found or not child of this node
+    override int childIndex(Node child) { 
+        for (int i = 0; i < _children.length; i++)
+            if (child is _children[i])
+                return i;
+        return -1;
+    }
+
+    /// append text child
+    override Node appendText(dstring s, int index = -1) {
+        Node item = document.createText(s);
+        _children.add(item, index >= 0 ? index : size_t.max);
+        return item;
+    }
+    /// append element child - by namespace and tag names
+    override Node appendElement(string ns, string tag, int index = -1) { 
+        Node item = document.createElement(ns, tag);
+        _children.add(item, index >= 0 ? index : size_t.max);
+        return item;
+    }
+    /// append element child - by namespace and tag ids
+    override Node appendElement(ns_id ns, elem_id tag, int index = -1) { 
+        Node item = document.createElement(ns, tag);
+        _children.add(item, index >= 0 ? index : size_t.max);
+        return item;
+    }
 }
 
 /// Document node
 class Document : Element {
 public:
     this() {
+        super(null, 0, 0);
         _elemIds.init!Tag();
         _attrIds.init!Attr();
         _nsIds.init!Ns();
+        _document = this;
+    }
+    /// create text node
+    Text createText(dstring text) {
+        return new Text(this, text);
+    }
+    /// create element node by namespace and tag ids
+    Element createElement(ns_id ns, elem_id tag) {
+        return new Element(this, ns, tag);
+    }
+    /// create element node by namespace and tag names
+    Element createElement(string ns, string tag) {
+        return new Element(this, internNs(ns), internTag(tag));
+    }
+
+    // Ids
+
+    /// return name for element tag id
+    string tagName(elem_id id) {
+        return _elemIds[id];
+    }
+    /// return name for namespace id
+    string nsName(ns_id id) {
+        return _nsIds[id];
+    }
+    /// return name for attribute id
+    string attrName(ns_id id) {
+        return _attrIds[id];
+    }
+    /// get id for element tag name
+    elem_id internTag(string s) {
+        if (s.empty)
+            return 0;
+        return _elemIds.intern(s);
+    }
+    /// get id for namespace name
+    ns_id internNs(string s) {
+        if (s.empty)
+            return 0;
+        return _nsIds.intern(s);
+    }
+    /// get id for namespace name
+    attr_id internAttr(string s) {
+        if (s.empty)
+            return 0;
+        return _attrIds.intern(s);
     }
 private:
     IdentMap!(elem_id) _elemIds;
@@ -93,12 +216,7 @@ private:
     IdentMap!(ns_id) _nsIds;
 }
 
-/// id type for interning namespaces
+
-alias ns_id = ushort;
-/// id type for interning element names
-alias elem_id = uint;
-/// id type for interning attribute names
-alias attr_id = ushort;
 
 /// remove trailing _ from string, e.g. "body_" -> "body"
 private string removeTrailingUnderscore(string s) {
@@ -112,11 +230,14 @@ struct IdentMap(ident_t) {
     /// initialize with elements of enum
     void init(E)() if (is(E == enum)) {
         foreach(member; EnumMembers!E) {
-            internString(removeTrailingUnderscore(member.to!string), member);
+            static if (member.to!int) {
+                //pragma(msg, "interning string '" ~ removeTrailingUnderscore(member.to!string) ~ "' for " ~ E.stringof);
+                intern(removeTrailingUnderscore(member.to!string), member);
+            }
         }
     }
     /// intern string - return ID assigned for it
-    ident_t internString(string s, ident_t id = 0) {
+    ident_t intern(string s, ident_t id = 0) {
         if (auto p = s in _stringToId)
             return *p;
         ident_t res;
@@ -133,12 +254,16 @@ struct IdentMap(ident_t) {
     }
     /// lookup id for string, return 0 if string is not found
     ident_t opIndex(string s) {
+        if (s.empty)
+            return 0;
         if (auto p = s in _stringToId)
             return *p;
         return 0;
     }
     /// lookup name for id, return null if not found
     string opIndex(ident_t id) {
+        if (!id)
+            return null;
         if (auto p = id in _idToString)
             return *p;
         return null;
@@ -187,5 +312,16 @@ unittest {
     assert(map[Tag.div].equal("div"));
 
     Document doc = new Document();
+    auto body_ = doc.appendElement(null, "body");
+    assert(body_.id == Tag.body_);
+    assert(body_.name.equal("body"));
+    auto div = body_.appendElement(null, "div");
+    assert(body_.childCount == 1);
+    assert(div.id == Tag.body_);
+    assert(div.name.equal("div"));
+    div.appendText("Some text"d);
+    assert(div.childCount == 1);
+    assert(div.child(0).text.equal("Some text"d));
+
     destroy(doc);
 }