dom: implement innerHTML setter

src/dom/element.zig

@@ -89,6 +89,28 @@ pub const Element = struct {
         return buf.toOwnedSlice();
     }
 
+    pub fn set_innerHTML(self: *parser.Element, str: []const u8) !void {
+        const node = parser.elementToNode(self);
+        const doc = try parser.nodeOwnerDocument(node) orelse return parser.DOMError.WrongDocument;
+        // parse the fragment
+        const fragment = try parser.documentParseFragmentFromStr(doc, str);
+
+        // remove existing children
+        try Node.removeChildren(node);
+
+        // get fragment body children
+        const children = try parser.documentFragmentBodyChildren(fragment) orelse return;
+
+        // append children to the node
+        const ln = try parser.nodeListLength(children);
+        var i: u32 = 0;
+        while (i < ln) {
+            defer i += 1;
+            const child = try parser.nodeListItem(children, i) orelse continue;
+            _ = try parser.nodeAppendChild(node, child);
+        }
+    }
+
     pub fn _hasAttributes(self: *parser.Element) !bool {
         return try parser.nodeHasAttributes(parser.elementToNode(self));
     }
@@ -435,6 +457,11 @@ pub fn testExecFn(
     var innerHTML = [_]Case{
         .{ .src = "document.getElementById('para').innerHTML", .ex = " And" },
         .{ .src = "document.getElementById('para-empty').innerHTML.trim()", .ex = "<span id=\"para-empty-child\"></span>" },
+
+        .{ .src = "let h = document.getElementById('para-empty')", .ex = "undefined" },
+        .{ .src = "const prev = h.innerHTML", .ex = "undefined" },
+        .{ .src = "h.innerHTML = prev; true", .ex = "true" },
+        .{ .src = "document.getElementById('para-empty').innerHTML.trim()", .ex = "<span id=\"para-empty-child\"></span>" },
     };
     try checkCases(js_env, &innerHTML);
 }

src/netsurf.zig

@@ -1514,6 +1514,22 @@ pub const Video = struct { base: *c.dom_html_element };
 // Document Fragment
 pub const DocumentFragment = c.dom_document_fragment;
 
+pub inline fn documentFragmentToNode(doc: *DocumentFragment) *Node {
+    return @as(*Node, @ptrCast(doc));
+}
+
+pub fn documentFragmentBodyChildren(doc: *DocumentFragment) !?*NodeList {
+    const node = documentFragmentToNode(doc);
+    const html = try nodeFirstChild(node) orelse return null;
+    // TODO unref
+    const head = try nodeFirstChild(html) orelse return null;
+    // TODO unref
+    const body = try nodeNextSibling(head) orelse return null;
+    // TODO unref
+
+    return try nodeGetChildNodes(body);
+}
+
 // Document Position
 
 pub const DocumentPosition = enum(u2) {
@@ -1859,6 +1875,53 @@ pub fn documentHTMLParse(reader: anytype, enc: ?[:0]const u8) !*DocumentHTML {
     return @as(*DocumentHTML, @ptrCast(doc.?));
 }
 
+pub fn documentParseFragmentFromStr(self: *Document, str: []const u8) !*DocumentFragment {
+    var fbs = std.io.fixedBufferStream(str);
+    return try documentParseFragment(self, fbs.reader(), "UTF-8");
+}
+
+pub fn documentParseFragment(self: *Document, reader: anytype, enc: ?[:0]const u8) !*DocumentFragment {
+    var parser: ?*c.dom_hubbub_parser = undefined;
+    var fragment: ?*c.dom_document_fragment = undefined;
+    var err: c.hubbub_error = undefined;
+
+    var params = c.dom_hubbub_parser_params{
+        .enc = null,
+        .fix_enc = true,
+        .msg = null,
+        .script = null,
+        .enable_script = false,
+        .ctx = null,
+        .daf = null,
+    };
+
+    if (enc) |e| params.enc = e;
+
+    err = c.dom_hubbub_fragment_parser_create(&params, self, &parser, &fragment);
+    try parserErr(err);
+    defer c.dom_hubbub_parser_destroy(parser);
+
+    var buffer: [1024]u8 = undefined;
+    var ln = buffer.len;
+    while (ln > 0) {
+        ln = try reader.read(&buffer);
+        err = c.dom_hubbub_parser_parse_chunk(parser, &buffer, ln);
+        // TODO handle encoding change error return.
+        // When the HTML contains a META tag with a different encoding than the
+        // original one, a c.DOM_HUBBUB_HUBBUB_ERR_ENCODINGCHANGE error is
+        // returned.
+        // In this case, we must restart the parsing with the new detected
+        // encoding. The detected encoding is stored in the document and we can
+        // get it with documentGetInputEncoding().
+        try parserErr(err);
+    }
+
+    err = c.dom_hubbub_parser_completed(parser);
+    try parserErr(err);
+
+    return @as(*DocumentFragment, @ptrCast(fragment.?));
+}
+
 // documentHTMLClose closes the document.
 pub fn documentHTMLClose(doc: *DocumentHTML) !void {
     const err = documentHTMLVtable(doc).close.?(doc);