browser: parse http content-type

src/browser/browser.zig

@@ -2,6 +2,7 @@ const std = @import("std");
 
 const parser = @import("../netsurf.zig");
 const Loader = @import("loader.zig").Loader;
+const Mime = @import("mime.zig");
 
 const jsruntime = @import("jsruntime");
 const Loop = jsruntime.Loop;
@@ -166,9 +167,19 @@ pub const Page = struct {
 
         // TODO handle charset
         // https://html.spec.whatwg.org/#content-type
-
-        // TODO check content-type
-        try self.loadHTMLDoc(&result);
+        const ct = result.headers.getFirstValue("Content-Type") orelse {
+            // no content type in HTTP headers.
+            // TODO try to sniff mime type from the body.
+            log.info("no content-type HTTP header", .{});
+            return;
+        };
+        const mime = try Mime.parse(ct);
+        if (mime.eql(Mime.HTML)) {
+            // TODO check content-type
+            try self.loadHTMLDoc(&result);
+        } else {
+            log.info("none HTML document: {s}", .{ct});
+        }
     }
 
     // https://html.spec.whatwg.org/#read-html

src/browser/mime.zig

@@ -14,6 +14,9 @@ mtype: []const u8,
 msubtype: []const u8,
 params: []const u8,
 
+pub const HTML = Self{ .mtype = "text", .msubtype = "html", .params = "" };
+pub const Javascript = Self{ .mtype = "application", .msubtype = "javascript", .params = "" };
+
 const reader = struct {
     s: []const u8,
     i: usize = 0,
@@ -125,12 +128,7 @@ pub fn parse(s: []const u8) Self.MimeError!Self {
     // limit input size
     if (ln > 255) return MimeError.TooBig;
 
-    var res = Self{
-        .mtype = "",
-        .msubtype = "",
-        .params = "",
-    };
-
+    var res = Self{ .mtype = "", .msubtype = "", .params = "" };
     var r = reader{ .s = s };
 
     res.mtype = trim(r.until('/'));
@@ -185,3 +183,9 @@ test "parse invalid" {
         try testing.expect(false);
     }
 }
+
+// Compare type and subtype.
+pub fn eql(self: Self, b: Self) bool {
+    if (!std.mem.eql(u8, self.mtype, b.mtype)) return false;
+    return std.mem.eql(u8, self.msubtype, b.msubtype);
+}