Create signup page

src/api/lib.zig

@@ -204,6 +204,13 @@ pub const FileResult = struct {
     data: []const u8,
 };
 
+pub const ValidInvite = struct {
+    code: []const u8,
+    kind: services.invites.Kind,
+    name: []const u8,
+    creator: UserResponse,
+};
+
 pub fn isAdminSetup(db: sql.Db) !bool {
     _ = services.communities.adminCommunityId(db) catch |err| switch (err) {
         error.NotFound => return false,
@@ -396,6 +403,12 @@ fn ApiConn(comptime DbConn: type) type {
             return try services.invites.get(self.db, invite_id, self.allocator);
         }
 
+        fn isInviteValid(invite: services.invites.Invite) bool {
+            if (invite.max_uses != null and invite.times_used >= invite.max_uses.?) return false;
+            if (invite.expires_at != null and DateTime.now().isAfter(invite.expires_at.?)) return false;
+            return true;
+        }
+
         pub fn register(self: *Self, username: []const u8, password: []const u8, opt: RegistrationOptions) !UserResponse {
             const tx = try self.db.beginOrSavepoint();
             const maybe_invite = if (opt.invite_code) |code|
@@ -406,8 +419,7 @@ fn ApiConn(comptime DbConn: type) type {
 
             if (maybe_invite) |invite| {
                 if (!Uuid.eql(invite.community_id, self.community.id)) return error.WrongCommunity;
-                if (invite.max_uses != null and invite.times_used >= invite.max_uses.?) return error.InviteExpired;
+                if (!isInviteValid(invite)) return error.InvalidInvite;
-                if (invite.expires_at != null and DateTime.now().isAfter(invite.expires_at.?)) return error.InviteExpired;
             }
 
             const invite_kind = if (maybe_invite) |inv| inv.kind else .user;
@@ -434,19 +446,18 @@ fn ApiConn(comptime DbConn: type) type {
                 },
             }
 
-            return self.getUser(user_id) catch |err| switch (err) {
+            const user = self.getUserUnchecked(tx, user_id) catch |err| switch (err) {
-                error.NotFound => error.Unexpected,
+                error.NotFound => return error.Unexpected,
-                else => err,
+                else => |e| return e,
             };
-        }
-
-        pub fn getUser(self: *Self, user_id: Uuid) !UserResponse {
-            const user = try services.actors.get(self.db, user_id, self.allocator);
             errdefer util.deepFree(self.allocator, user);
 
-            if (self.user_id == null) {
+            try tx.commit();
-                if (!Uuid.eql(self.community.id, user.community_id)) return error.NotFound;
+            return user;
-            }
+        }
+
+        fn getUserUnchecked(self: *Self, db: anytype, user_id: Uuid) !UserResponse {
+            const user = try services.actors.get(db, user_id, self.allocator);
 
             return UserResponse{
                 .id = user.id,
@@ -469,6 +480,17 @@ fn ApiConn(comptime DbConn: type) type {
             };
         }
 
+        pub fn getUser(self: *Self, user_id: Uuid) !UserResponse {
+            const user = try self.getUserUnchecked(self.db, user_id);
+            errdefer util.deepFree(self.allocator, user);
+
+            if (self.user_id == null) {
+                if (!Uuid.eql(self.community.id, user.community_id)) return error.NotFound;
+            }
+
+            return user;
+        }
+
         pub fn createNote(self: *Self, content: []const u8) !NoteResponse {
             // You cannot post on admin accounts
             if (self.community.kind == .admin) return error.WrongCommunity;
@@ -747,5 +769,33 @@ fn ApiConn(comptime DbConn: type) type {
             if (!Uuid.eql(id, self.user_id orelse return error.NoToken)) return error.AccessDenied;
             try services.actors.updateProfile(self.db, id, data, self.allocator);
         }
+
+        pub fn validateInvite(self: *Self, code: []const u8) !ValidInvite {
+            const invite = services.invites.getByCode(
+                self.db,
+                code,
+                self.community.id,
+                self.allocator,
+            ) catch |err| switch (err) {
+                error.NotFound => return error.InvalidInvite,
+                else => return error.DatabaseFailure,
+            };
+            errdefer util.deepFree(self.allocator, invite);
+
+            if (!Uuid.eql(invite.community_id, self.community.id)) return error.InvalidInvite;
+            if (!isInviteValid(invite)) return error.InvalidInvite;
+
+            const creator = self.getUserUnchecked(self.db, invite.created_by) catch |err| switch (err) {
+                error.NotFound => return error.Unexpected,
+                else => return error.DatabaseFailure,
+            };
+
+            return ValidInvite{
+                .code = invite.code,
+                .name = invite.name,
+                .kind = invite.kind,
+                .creator = creator,
+            };
+        }
     };
 }

src/api/services/actors.zig

@@ -67,12 +67,12 @@ pub const UsernameValidationError = error{
 ///     - Be at least 1 character
 ///     - Be no more than 32 characters
 ///     - All characters are in [A-Za-z0-9_]
-pub fn validateUsername(username: []const u8) UsernameValidationError!void {
+pub fn validateUsername(username: []const u8, lax: bool) UsernameValidationError!void {
     if (username.len == 0) return error.UsernameEmpty;
     if (username.len > max_username_chars) return error.UsernameTooLong;
 
     for (username) |ch| {
-        const valid = std.ascii.isAlNum(ch) or ch == '_';
+        const valid = std.ascii.isAlNum(ch) or ch == '_' or (lax and ch == '.');
         if (!valid) return error.UsernameContainsInvalidChar;
     }
 }
@@ -81,11 +81,12 @@ pub fn create(
     db: anytype,
     username: []const u8,
     community_id: Uuid,
+    lax_username: bool,
     alloc: std.mem.Allocator,
 ) CreateError!Uuid {
     const id = Uuid.randV4(util.getThreadPrng());
 
-    try validateUsername(username);
+    try validateUsername(username, lax_username);
 
     db.insert("actor", .{
         .id = id,
@@ -153,8 +154,11 @@ pub fn get(db: anytype, id: Uuid, alloc: std.mem.Allocator) GetError!Actor {
         .{id},
         alloc,
     ) catch |err| switch (err) {
-        error.NoRows => error.NotFound,
+        error.NoRows => return error.NotFound,
-        else => error.DatabaseFailure,
+        else => |e| {
+            std.log.err("{}, {?}", .{ e, @errorReturnTrace() });
+            return error.DatabaseFailure;
+        },
     };
 }
 

src/api/services/auth.zig

@@ -36,14 +36,14 @@ pub fn register(
     if (password.len < min_password_chars) return error.PasswordTooShort;
 
     // perform pre-validation to avoid having to hash the password if it fails
-    try actors.validateUsername(username);
+    try actors.validateUsername(username, false);
     const hash = try hashPassword(password, alloc);
     defer alloc.free(hash);
 
     const tx = db.beginOrSavepoint() catch return error.DatabaseFailure;
     errdefer tx.rollback();
 
-    const id = try actors.create(tx, username, community_id, alloc);
+    const id = try actors.create(tx, username, community_id, false, alloc);
     tx.insert("account", .{
         .id = id,
         .invite_id = options.invite_id,

src/api/services/communities.zig

@@ -97,7 +97,7 @@ pub fn create(db: anytype, origin: []const u8, options: CreateOptions, alloc: st
     }, alloc);
 
     if (options.kind == .local) {
-        const actor_id = actors.create(tx, "community.actor", id, alloc) catch |err| switch (err) {
+        const actor_id = actors.create(tx, "community.actor", id, true, alloc) catch |err| switch (err) {
             error.UsernameContainsInvalidChar,
             error.UsernameTooLong,
             error.UsernameEmpty,
@@ -109,7 +109,6 @@ pub fn create(db: anytype, origin: []const u8, options: CreateOptions, alloc: st
             \\UPDATE community
             \\SET community_actor_id = $1
             \\WHERE id = $2
-            \\LIMIT 1
         , .{ actor_id, id }, alloc);
     }
 

src/http/middleware.zig

@@ -201,7 +201,7 @@ pub fn CatchErrors(comptime ErrorHandler: type) type {
                 return self.error_handler.handle(
                     req,
                     res,
-                    addField(ctx, "err", err),
+                    addField(addField(ctx, "err", err), "err_trace", @errorReturnTrace()),
                     next,
                 );
             };
@@ -218,7 +218,10 @@ pub fn catchErrors(error_handler: anytype) CatchErrors(@TypeOf(error_handler)) {
 pub const default_error_handler = struct {
     fn handle(_: @This(), req: anytype, res: anytype, ctx: anytype, _: anytype) !void {
         const should_log = !@import("builtin").is_test;
-        if (should_log) std.log.err("Error {} on uri {s}", .{ ctx.err, req.uri });
+        if (should_log) {
+            std.log.err("Error {} on uri {s}", .{ ctx.err, req.uri });
+            std.log.debug("Additional details: {?}", .{ctx.err_trace});
+        }
 
         // Tell the server to close the connection after this request
         res.should_close = true;
@@ -335,12 +338,12 @@ pub fn Router(comptime Routes: type) type {
             _ = next;
 
             inline for (self.routes) |r| {
-                if (r.handle(req, res, ctx, {})) |_|
+                if (r.handle(req, res, ctx, {}))
                     // success
                     return
                 else |err| switch (err) {
                     error.RouteMismatch => {},
-                    else => return err,
+                    else => |e| return e,
                 }
             }
 
@@ -406,10 +409,10 @@ pub const Route = struct {
     }
 
     pub fn handle(self: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
-        return if (self.applies(req, ctx))
+        if (self.applies(req, ctx))
-            next.handle(req, res, ctx, {})
+            return next.handle(req, res, ctx, {})
         else
-            error.RouteMismatch;
+            return error.RouteMismatch;
     }
 };
 

src/main/controllers/web.zig

@@ -1,5 +1,6 @@
 const std = @import("std");
 const util = @import("util");
+const http = @import("http");
 const controllers = @import("../controllers.zig");
 
 pub const routes = .{
@@ -10,6 +11,9 @@ pub const routes = .{
     controllers.apiEndpoint(cluster.overview),
     controllers.apiEndpoint(media),
     controllers.apiEndpoint(static),
+    controllers.apiEndpoint(signup.page),
+    controllers.apiEndpoint(signup.with_invite),
+    controllers.apiEndpoint(signup.submit),
 };
 
 const static = struct {
@@ -94,6 +98,101 @@ const login = struct {
     }
 };
 
+const signup = struct {
+    const tmpl = @embedFile("./web/signup.tmpl.html");
+
+    fn servePage(
+        invite_code: ?[]const u8,
+        error_msg: ?[]const u8,
+        status: http.Status,
+        res: anytype,
+        srv: anytype,
+    ) !void {
+        const invite = if (invite_code) |code| srv.validateInvite(code) catch |err| switch (err) {
+            error.InvalidInvite => return servePage(null, "Invite is not valid", .bad_request, res, srv),
+            else => |e| return e,
+        } else null;
+        defer util.deepFree(srv.allocator, invite);
+
+        try res.template(status, srv, tmpl, .{
+            .error_msg = error_msg,
+            .invite = invite,
+        });
+    }
+
+    const page = struct {
+        pub const path = "/signup";
+        pub const method = .GET;
+
+        pub fn handler(_: anytype, res: anytype, srv: anytype) !void {
+            try servePage(null, null, .ok, res, srv);
+        }
+    };
+
+    const with_invite = struct {
+        pub const path = "/invite/:code";
+        pub const method = .GET;
+
+        pub const Args = struct {
+            code: []const u8,
+        };
+
+        pub fn handler(req: anytype, res: anytype, srv: anytype) !void {
+            std.log.debug("{s}", .{req.args.code});
+            try servePage(req.args.code, null, .ok, res, srv);
+        }
+    };
+
+    const submit = struct {
+        pub const path = "/signup";
+        pub const method = .POST;
+
+        pub const Body = struct {
+            username: []const u8,
+            password: []const u8,
+            email: ?[]const u8 = null,
+            invite_code: ?[]const u8 = null,
+        };
+
+        pub fn handler(req: anytype, res: anytype, srv: anytype) !void {
+            const user = srv.register(req.body.username, req.body.password, .{
+                .email = req.body.email,
+                .invite_code = req.body.invite_code,
+            }) catch |err| {
+                var status: http.Status = .bad_request;
+                const err_msg = switch (err) {
+                    error.UsernameEmpty => "Username cannot be empty",
+                    error.UsernameContainsInvalidChar => "Username must be composed of alphanumeric characters and underscore",
+                    error.UsernameTooLong => "Username too long",
+                    error.PasswordTooShort => "Password too short, must be at least 12 chars",
+
+                    error.UsernameTaken => blk: {
+                        status = .unprocessable_entity;
+                        break :blk "Username is already registered";
+                    },
+                    else => blk: {
+                        status = .internal_server_error;
+                        break :blk "an internal error occurred";
+                    },
+                };
+
+                return servePage(req.body.invite_code, err_msg, status, res, srv);
+            };
+            defer util.deepFree(srv.allocator, user);
+
+            const token = try srv.login(req.body.username, req.body.password);
+
+            try res.headers.put("Location", index.path);
+            var buf: [64]u8 = undefined;
+            const cookie_name = try std.fmt.bufPrint(&buf, "token.{s}", .{req.body.username});
+            try res.headers.setCookie(cookie_name, token.token, .{});
+            try res.headers.setCookie("active_account", req.body.username, .{ .HttpOnly = false });
+
+            try res.status(.see_other);
+        }
+    };
+};
+
 const global_timeline = struct {
     pub const path = "/timelines/global";
     pub const method = .GET;

src/main/controllers/web/signup.tmpl.html

@@ -0,0 +1,54 @@
+<header>
+  <h2>{ %community.name }</h2>
+</header>
+<form action="/signup" method="post">
+  <h3>Sign Up</h3>
+  {#if .error_msg |$msg| =}
+  <div class="error">Error: {$msg}</div>
+  {= /if}
+  {#if .invite |$invite| =}
+  <div>
+    <div>You are about to accept an invite from:</div>
+    <div class="user-mini">
+      <div>
+      {=#if $invite.creator.display_name |$name|=}
+        {$name}
+      {= #else =}
+        {$invite.creator.username}
+      {= /if =}
+      </div>
+      <div>@{$invite.creator.username}@{$invite.creator.host}</div>
+    </div>
+    {#if @isTag($invite.kind, community_owner) =}
+      <div>This act will make your new account the owner of { %community.name }</div>
+    {/if =}
+  </div>
+  {=/if}
+  <label>
+    <div>Username <span class="required">(required)</span></div>
+    <div class="textinput username">
+      <span class="prefix">@</span>
+      <input type="text" name="username" placeholder="xion" />
+      <span class="suffix">@{ %community.host }</span>
+    </div>
+    <div class="form-helpinfo">Up to 32 characters, allows alphanumeric characters and underscores.</div>
+  </label>
+  <label>
+    <div>Password <span class="required">(required)</span></div>
+    <div class="textinput">
+      <span class="prefix"><i class="fa-solid fa-key fa-fw"></i></span>
+      <input type="password" name="password" placeholder="hunter2" />
+    </div>
+  </label>
+  <label>
+    <div>Email</div>
+    <div class="textinput">
+      <span class="prefix"><i class="fa-solid fa-envelope fa-fw"></i></span>
+      <input type="email" name="email" placeholder="me@exmaple.com" />
+    </div>
+  </label>
+  {#if .invite |$invite| =}
+  <input style="display: none" type="text" name="invite_code" value="{$invite.code}" />
+  {/if =}
+  <button type="submit">Sign up</button>
+</form>

src/sql/engines/sqlite.zig

@@ -313,6 +313,11 @@ fn getColumn(stmt: *c.sqlite3_stmt, comptime T: type, idx: u15, alloc: ?Allocato
         c.SQLITE_FLOAT => getColumnFloat(stmt, T, idx),
         c.SQLITE_TEXT => getColumnText(stmt, T, idx, alloc),
         c.SQLITE_NULL => {
+            if (T == DateTime) {
+                std.log.warn("SQLite: Treating NULL as DateTime epoch", .{});
+                return std.mem.zeroes(DateTime);
+            }
+
             if (@typeInfo(T) != .Optional) {
                 std.log.err("SQLite column {}: Expected value of type {}, got (null)", .{ idx, T });
                 return error.ResultTypeMismatch;

src/sql/lib.zig

@@ -304,8 +304,8 @@ const Row = union(Engine) {
     fn get(self: Row, comptime T: type, idx: u15, alloc: ?Allocator) common.GetError!T {
         if (T == void) return;
         return switch (self) {
-            .postgres => |pg| pg.get(T, idx, alloc),
+            .postgres => |pg| try pg.get(T, idx, alloc),
-            .sqlite => |lite| lite.get(T, idx, alloc),
+            .sqlite => |lite| try lite.get(T, idx, alloc),
         };
     }
 };
@@ -420,7 +420,7 @@ fn Tx(comptime tx_level: u8) type {
             if (tx_level != 0) @compileError("close must be called on root db");
             if (self.conn.current_tx_level != 0) {
                 std.log.warn("Database released while transaction in progress!", .{});
-                self.rollbackUnchecked() catch {};
+                self.rollbackUnchecked() catch {}; // TODO: Burn database connection
             }
 
             if (!self.conn.in_use.swap(false, .AcqRel)) @panic("Double close on db conection");
@@ -719,6 +719,7 @@ fn Tx(comptime tx_level: u8) type {
 
         fn rollbackUnchecked(self: Self) !void {
             try self.execInternal("ROLLBACK", {}, .{}, false);
+            self.conn.current_tx_level = 0;
         }
     };
 }

src/template/lib.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 
 pub fn main() !void {
+    const Enum = enum { foo, bar, baz };
     try execute(
         std.io.getStdOut().writer(),
         .{ .test_tmpl = "{.x} {%context_foo}" },
@@ -15,8 +16,15 @@ pub fn main() !void {
             .bar = .{ .x = "x" },
             .qux = false,
             .quxx = true,
+            .quxx2 = true,
             .maybe_foo = @as(?[]const u8, "foo"),
             .maybe_bar = @as(?[]const u8, null),
+            .snap = Enum.bar,
+            .crackle = union(Enum) {
+                foo: []const u8,
+                bar: []const u8,
+                baz: []const u8,
+            }{ .foo = "abcd" },
             .x = "y",
         },
         .{
@@ -119,6 +127,49 @@ fn executeStatement(
                 };
             }
         },
+        .@"switch" => |switch_stmt| {
+            const expr = evaluateExpression(switch_stmt.expression, args, captures, context);
+
+            const exhaustive = switch_stmt.cases.len == std.meta.fields(@TypeOf(expr)).len;
+
+            if (exhaustive and switch_stmt.else_branch != null) @compileError("Unused else branch in switch");
+            if (!exhaustive and switch_stmt.else_branch == null) @compileError("Not all switch cases covered");
+
+            var found = false;
+            inline for (switch_stmt.cases) |case| {
+                if (std.meta.isTag(expr, case.header.tag)) {
+                    found = true;
+                    if (case.header.capture) |capture| {
+                        try executeTemplate(
+                            writer,
+                            templates,
+                            case.subtemplate,
+                            args,
+                            addCapture(captures, capture, @field(expr, case.header.tag)),
+                            context,
+                        );
+                    } else {
+                        try executeTemplate(
+                            writer,
+                            templates,
+                            case.subtemplate,
+                            args,
+                            captures,
+                            context,
+                        );
+                    }
+                }
+            } else if (!found) if (switch_stmt.else_branch) |subtemplate| {
+                try executeTemplate(
+                    writer,
+                    templates,
+                    subtemplate,
+                    args,
+                    captures,
+                    context,
+                );
+            };
+        },
         .call_template => |call| {
             const new_template = @field(templates, call.template_name);
             try execute(
@@ -168,6 +219,10 @@ fn EvaluateExpression(
         .arg_deref => |names| Deref(Args, names),
         .capture_deref => |names| Deref(Captures, names),
         .context_deref => |names| Deref(Context, names),
+        .equals => bool,
+        .builtin => |call| switch (call.*) {
+            .isTag => bool,
+        },
     };
 }
 
@@ -181,6 +236,22 @@ fn evaluateExpression(
         .arg_deref => |names| deref(args, names),
         .capture_deref => |names| deref(captures, names),
         .context_deref => |names| deref(context, names),
+        .equals => |eql| {
+            const lhs = evaluateExpression(eql.lhs, args, captures, context);
+            const rhs = evaluateExpression(eql.rhs, args, captures, context);
+            const T = @TypeOf(lhs, rhs);
+            if (comptime std.meta.trait.isZigString(T)) {
+                return std.mem.eql(u8, lhs, rhs);
+            } else if (comptime std.meta.trait.isContainer(T) and @hasDecl(T, "eql")) {
+                return T.eql(lhs, rhs);
+            } else return lhs == rhs;
+        },
+        .builtin => |call| switch (call.*) {
+            .isTag => |hdr| {
+                const val = evaluateExpression(hdr.expression, args, captures, context);
+                return std.meta.isTag(val, hdr.tag);
+            },
+        },
     };
 }
 
@@ -214,6 +285,7 @@ const TemplateType = enum {
     for_block,
     if_block,
     if_else_block,
+    switch_block,
 };
 
 const TemplateParseResult = struct {
@@ -270,6 +342,7 @@ fn parseTemplate(
     comptime template_type: TemplateType,
 ) TemplateParseResult {
     comptime {
+        @setEvalBranchQuota(tokens.len * 100);
         var i: usize = start;
         var current_text: []const u8 = "";
         var items: []const TemplateItem = &.{};
@@ -313,6 +386,41 @@ fn parseTemplate(
                             }};
                             i = subtemplate.new_idx;
                         },
+                        .switch_header => |header| {
+                            var cases: []const Case = &.{};
+                            var else_branch: ?[]const TemplateItem = null;
+                            var last_header: CaseHeader = header.first_case;
+                            var is_else = false;
+                            while (true) {
+                                const case = parseTemplate(tokens, i + 1, .switch_block);
+                                i = case.new_idx;
+
+                                if (!is_else) {
+                                    cases = cases ++ [_]Case{.{
+                                        .header = last_header,
+                                        .subtemplate = case.items,
+                                    }};
+                                } else {
+                                    else_branch = case.items;
+                                }
+                                switch (case.closing_block.?.block) {
+                                    .end_switch => break,
+                                    .@"else" => is_else = true,
+                                    .case_header => |case_header| last_header = case_header,
+                                    else => @compileError("Unexpected token"),
+                                }
+                            }
+
+                            items = items ++ [_]TemplateItem{.{
+                                .statement = .{
+                                    .@"switch" = .{
+                                        .expression = header.expression,
+                                        .cases = cases,
+                                        .else_branch = else_branch,
+                                    },
+                                },
+                            }};
+                        },
                         .end_for => if (template_type == .for_block)
                             break cb
                         else
@@ -325,13 +433,17 @@ fn parseTemplate(
                             break cb
                         else
                             @compileError("Unexpected #elif tag"),
-                        .@"else" => if (template_type == .if_block)
+                        .@"else" => if (template_type == .if_block or template_type == .switch_block)
                             break cb
                         else
                             @compileError("Unexpected #else tag"),
                         .call_template => |call| items = items ++ [_]TemplateItem{.{
                             .statement = .{ .call_template = call },
                         }},
+                        .end_switch, .case_header => if (template_type == .switch_block)
+                            break cb
+                        else
+                            @compileError("Unexpected /switch tag"),
                     }
                 },
             }
@@ -390,6 +502,8 @@ fn parseTemplateTokens(comptime tokens: ControlTokenIter) []const TemplateToken
             .at => items = items ++ [_]TemplateToken{.{ .text = "@" }},
             .comma => items = items ++ [_]TemplateToken{.{ .text = "," }},
             .percent => items = items ++ [_]TemplateToken{.{ .text = "%" }},
+            .open_paren => items = items ++ [_]TemplateToken{.{ .text = "(" }},
+            .close_paren => items = items ++ [_]TemplateToken{.{ .text = ")" }},
         };
 
         return items;
@@ -400,29 +514,108 @@ fn parseExpression(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIt
     comptime {
         var iter = tokens;
 
-        var expr: Expression = while (iter.next()) |token| switch (token) {
+        var last_valid_iter: ?ControlTokenIter = null;
+        var expr: ?Expression = null;
+        while (iter.next()) |token| switch (token) {
             .whitespace => {},
             .period => {
                 const names = parseDeref(iter);
                 iter = names.new_iter;
-                break .{ .arg_deref = names.item };
+                if (expr != null) break;
+                expr = .{ .arg_deref = names.item };
+                last_valid_iter = iter;
             },
             .dollar => {
                 const names = parseDeref(iter);
                 iter = names.new_iter;
-                break .{ .capture_deref = names.item };
+                if (expr != null) break;
+                expr = .{ .capture_deref = names.item };
+                last_valid_iter = iter;
             },
             .percent => {
                 const names = parseDeref(iter);
                 iter = names.new_iter;
-                break .{ .context_deref = names.item };
+                if (expr != null) break;
+                expr = .{ .context_deref = names.item };
+                last_valid_iter = iter;
             },
-            else => @compileError("TODO"),
+            .equals => {
+                const next = iter.next() orelse break;
+                if (next == .equals) {
+                    const lhs = expr orelse break;
+                    const rhs = parseExpression(iter);
+                    iter = rhs.new_iter;
+
+                    expr = .{
+                        .equals = &.{
+                            .lhs = lhs,
+                            .rhs = rhs.item,
+                        },
+                    };
+                    last_valid_iter = iter;
+                } else break;
+            },
+            .at => {
+                if (expr != null) break;
+                const builtin = parseBuiltin(iter);
+                iter = builtin.new_iter;
+                expr = .{ .builtin = &builtin.item };
+                last_valid_iter = iter;
+            },
+            else => break,
         };
 
+        return .{
+            .new_iter = last_valid_iter orelse @compileError("Invalid Expression"),
+            .item = expr orelse @compileError("Invalid Expression"),
+        };
+    }
+}
+
+fn expectToken(comptime token: ?ControlToken, comptime exp: std.meta.Tag(ControlToken)) void {
+    comptime {
+        if (token == null) @compileError("Unexpected End Of Template");
+        const token_tag = std.meta.activeTag(token.?);
+
+        if (token_tag != exp)
+            @compileError("Expected " ++ @tagName(exp) ++ ", got " ++ @tagName(token_tag));
+    }
+}
+
+fn parseBuiltin(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIter, BuiltinCall) {
+    comptime {
+        var iter = tokens;
+        const builtin = blk: {
+            const next = iter.next() orelse @compileError("Invalid Builtin");
+            if (next != .text) @compileError("Invalid Builtin");
+            break :blk std.meta.stringToEnum(Builtin, next.text) orelse @compileError("Invalid Builtin");
+        };
+
+        iter = skipWhitespace(iter);
+        expectToken(iter.next(), .open_paren);
+        iter = skipWhitespace(iter);
+        const call = switch (builtin) {
+            .isTag => blk: {
+                const expr = parseExpression(iter);
+                iter = expr.new_iter;
+                expectToken(iter.next(), .comma);
+                iter = skipWhitespace(iter);
+                const tag = iter.next();
+                expectToken(tag, .text);
+                break :blk .{
+                    .isTag = .{
+                        .tag = tag.?.text,
+                        .expression = expr.item,
+                    },
+                };
+            },
+        };
+        iter = skipWhitespace(iter);
+        expectToken(iter.next(), .close_paren);
+
         return .{
             .new_iter = iter,
-            .item = expr,
+            .item = call,
         };
     }
 }
@@ -471,6 +664,16 @@ fn parseControlBlock(comptime tokens: ControlTokenIter) ParseResult(ControlToken
                         iter = result.new_iter;
                         break .{ .call_template = result.item };
                     },
+                    .@"switch" => {
+                        const result = parseSwitchHeader(iter);
+                        iter = result.new_iter;
+                        break .{ .switch_header = result.item };
+                    },
+                    .case => {
+                        const result = parseCaseHeader(iter);
+                        iter = result.new_iter;
+                        break .{ .case_header = result.item };
+                    },
 
                     //else => @compileError("TODO"),
                 }
@@ -484,6 +687,7 @@ fn parseControlBlock(comptime tokens: ControlTokenIter) ParseResult(ControlToken
                 switch (keyword) {
                     .@"for" => break .{ .end_for = {} },
                     .@"if" => break .{ .end_if = {} },
+                    .@"switch" => break .{ .end_switch = {} },
                 }
             },
             .period, .dollar, .percent => {
@@ -518,7 +722,7 @@ fn parseControlBlock(comptime tokens: ControlTokenIter) ParseResult(ControlToken
             },
             else => {
                 @compileLog(iter.row);
-                @compileError("TODO" ++ @tagName(token));
+                @compileError("TODO " ++ @tagName(token) ++ " " ++ token.text);
             },
         };
 
@@ -642,6 +846,57 @@ fn parseIfHeader(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIter
     }
 }
 
+fn parseCaseHeader(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIter, CaseHeader) {
+    comptime {
+        var iter = skipWhitespace(tokens);
+        const tag = iter.next();
+        expectToken(tag, .text);
+
+        const captures = tryParseCapture(iter);
+        if (captures) |cap| {
+            if (cap.item.len == 1) {
+                return .{
+                    .new_iter = cap.new_iter,
+                    .item = CaseHeader{
+                        .tag = tag.?.text,
+                        .capture = cap.item[0],
+                    },
+                };
+            } else @compileError("Only one capture allowed for case statements");
+        }
+
+        return .{
+            .new_iter = iter,
+            .item = .{
+                .tag = tag.?.text,
+                .capture = null,
+            },
+        };
+    }
+}
+
+fn parseSwitchHeader(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIter, SwitchHeader) {
+    comptime {
+        const condition = parseExpression(tokens);
+        var iter = skipWhitespace(condition.new_iter);
+
+        const next = iter.next();
+        expectToken(next, .text);
+        if (!std.mem.eql(u8, next.?.text, "case")) @compileError("Expected case following switch condition");
+
+        iter = skipWhitespace(iter);
+        const first = parseCaseHeader(iter);
+
+        return .{
+            .new_iter = first.new_iter,
+            .item = .{
+                .expression = condition.item,
+                .first_case = first.item,
+            },
+        };
+    }
+}
+
 fn parseDeref(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIter, []const []const u8) {
     comptime {
         var iter = tokens;
@@ -651,7 +906,7 @@ fn parseDeref(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIter, [
             switch (token) {
                 .whitespace => {},
                 .text => |text| {
-                    if (wants != .text) @compileError("Unexpected token \"" ++ text ++ "\"");
+                    if (wants == .period) break;
                     fields = fields ++ [1][]const u8{text};
                     wants = .period;
                 },
@@ -659,13 +914,15 @@ fn parseDeref(comptime tokens: ControlTokenIter) ParseResult(ControlTokenIter, [
                     if (wants != .period) @compileError("Unexpected token \".\"");
                     wants = .text;
                 },
-                else => if (wants == .period or fields.len == 0) return .{
+                else => if (wants == .period or fields.len == 0) break else @compileError("Unexpected token"),
-                    .new_iter = iter,
-                    .item = fields,
-                } else @compileError("Unexpected token"),
             }
             _ = iter.next();
         }
+
+        return .{
+            .new_iter = iter,
+            .item = fields,
+        };
     }
 }
 
@@ -702,10 +959,17 @@ const TemplateItem = union(enum) {
     statement: Statement,
 };
 
+const EqualsExpr = struct {
+    lhs: Expression,
+    rhs: Expression,
+};
+
 const Expression = union(enum) {
     arg_deref: []const []const u8,
     capture_deref: []const []const u8,
     context_deref: []const []const u8,
+    equals: *const EqualsExpr,
+    builtin: *const BuiltinCall,
 };
 
 const For = struct {
@@ -727,6 +991,27 @@ const If = struct {
     },
 };
 
+const Case = struct {
+    header: CaseHeader,
+    subtemplate: []const TemplateItem,
+};
+
+const SwitchHeader = struct {
+    expression: Expression,
+    first_case: CaseHeader,
+};
+
+const CaseHeader = struct {
+    tag: []const u8,
+    capture: ?[]const u8,
+};
+
+const Switch = struct {
+    expression: Expression,
+    cases: []const Case,
+    else_branch: ?[]const TemplateItem,
+};
+
 const CallTemplate = struct {
     template_name: []const u8,
     args: Expression,
@@ -741,6 +1026,7 @@ const Statement = union(enum) {
     expression: Expression,
     @"for": For,
     @"if": If,
+    @"switch": Switch,
     call_template: CallTemplate,
 };
 
@@ -754,6 +1040,9 @@ const ControlBlock = struct {
         @"else": void,
         elif_header: IfHeader,
         call_template: CallTemplate,
+        switch_header: SwitchHeader,
+        case_header: CaseHeader,
+        end_switch: void,
     };
     block: Data,
     strip_before: bool,
@@ -766,11 +1055,25 @@ const Keyword = enum {
     @"else",
     @"elif",
     @"template",
+    @"switch",
+    @"case",
 };
 
 const EndKeyword = enum {
     @"for",
     @"if",
+    @"switch",
+};
+
+const Builtin = enum {
+    isTag,
+};
+
+const BuiltinCall = union(Builtin) {
+    isTag: struct {
+        tag: []const u8,
+        expression: Expression,
+    },
 };
 
 const ControlToken = union(enum) {
@@ -787,6 +1090,8 @@ const ControlToken = union(enum) {
     at: void,
     comma: void,
     percent: void,
+    open_paren: void,
+    close_paren: void,
 };
 
 const ControlTokenIter = struct {
@@ -819,6 +1124,8 @@ const ControlTokenIter = struct {
             '@' => return .{ .at = {} },
             ',' => return .{ .comma = {} },
             '%' => return .{ .percent = {} },
+            '(' => return .{ .open_paren = {} },
+            ')' => return .{ .close_paren = {} },
             ' ', '\t', '\n', '\r' => {
                 var idx: usize = 0;
                 while (idx < remaining.len and std.mem.indexOfScalar(u8, " \t\n\r", remaining[idx]) != null) : (idx += 1) {}
@@ -830,7 +1137,7 @@ const ControlTokenIter = struct {
             },
             else => {
                 var idx: usize = 0;
-                while (idx < remaining.len and std.mem.indexOfScalar(u8, "{}.#|$/=@ \t\n\r", remaining[idx]) == null) : (idx += 1) {}
+                while (idx < remaining.len and std.mem.indexOfScalar(u8, "{}.#|$/=@,%() \t\n\r", remaining[idx]) == null) : (idx += 1) {}
 
                 self.start += idx - 1;
                 return .{ .text = remaining[0..idx] };

src/template/test.tmp.html

@@ -14,6 +14,10 @@
       {$b}:
       {= /for =}
       {= /for}
+      {#if .quxx == .quxx2}eql{#else}neq{/if}
+      {#if .quxx == .qux}eql{#else}neq{/if}
+      {#if @isTag(.snap, foo)}foo{/if}
+      {#if @isTag(.snap, bar)}bar{/if}
       {#if .qux=}
         qux
       {=#elif .quxx=}
@@ -22,6 +26,22 @@
         neither
       {=/if}
 
+      {#switch .snap case foo =}
+        foo
+      {= #case bar =}
+        bar
+      {= #else =}
+        other
+      {= /switch}
+
+      crackle: {#switch .crackle case foo |$foo|=}
+        foo:{$foo}
+      {= #case bar |$bar|=}
+        bar:{$bar}
+      {= #else =}
+        other
+      {= /switch}
+
       {#if .maybe_foo |$v|}{$v}{#else}null{/if}
       {#if .maybe_bar |$v|}{$v}{#else}null{/if}
       {#if .maybe_foo |$_|}abcd{#else}null{/if}

src/util/serialize.zig

@@ -349,10 +349,14 @@ pub fn DeserializerContext(comptime Result: type, comptime From: type, comptime
                             any_missing = true;
                         }
                     }
-                    if (any_missing) {
+                    if (any_missing and any_explicit) return error.MissingField;
-                        return if (any_explicit) error.MissingField else null;
-                    }
 
+                    if (!any_explicit) {
+                        inline for (info.fields) |field, i| {
+                            if (fields_alloced[i]) self.deserializeFree(allocator, @field(result, field.name));
+                        }
+                        return null;
+                    }
                     return result;
                 },
 

static/site.css

@@ -92,6 +92,10 @@ form[action*=login] .textinput span.suffix {
   outline: none;
 }
 
+.form-helpinfo {
+  font-size: small;
+}
+
 button, a.button {
   padding: 5px;
   border-radius: 10px;