Inertia - WIP

Not yet complete but provides some functionality with internal templates
that Websockets/Channels needs so merging in to main and can pick up
later.

build.zig

@@ -12,11 +12,22 @@ const use_llvm_default = builtin.os.tag != .linux;
 pub fn build(b: *std.Build) !void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
+    var jetzig_templates_path = std.ArrayList([]const u8).init(b.allocator);
+    try jetzig_templates_path.append("/");
+    var it = std.mem.splitSequence(
+        u8,
+        try b.path("src/jetzig/templates").getPath3(b, null).toString(b.allocator),
+        std.fs.path.sep_str,
+    );
+    while (it.next()) |segment| {
+        try jetzig_templates_path.append(segment);
+    }
     const templates_paths = try zmpl_build.templatesPaths(
         b.allocator,
         &.{
             .{ .prefix = "views", .path = &.{ "src", "app", "views" } },
             .{ .prefix = "mailers", .path = &.{ "src", "app", "mailers" } },
+            .{ .prefix = "jetzig", .path = jetzig_templates_path.items },
         },
     );
 

build.zig.zon

@@ -25,8 +25,8 @@
             .hash = "jetkv-0.0.0-zCv0fmCGAgCyYqwHjk0P5KrYVRew1MJAtbtAcIO-WPpT",
         },
         .zmpl = .{
-            .url = "https://github.com/jetzig-framework/zmpl/archive/c57fc9b83027e8c1459d9625c3509f59f0fb89f3.tar.gz",
+            .url = "https://github.com/jetzig-framework/zmpl/archive/89ee0ce9b4c96c316cc0575266fb66c864f24a49.tar.gz",
-            .hash = "zmpl-0.0.1-SYFGBgdqAwDeA6xm4KAhpKoNrWs5CMQK6x447zhWclCs",
+            .hash = "zmpl-0.0.1-SYFGBtuNAwCj2YbqnoEJt3bk1iFIZjGK6JwMc72toZBR",
         },
         .httpz = .{
             .url = "https://github.com/karlseguin/http.zig/archive/37d7cb9819b804ade5f4b974b82f8dd0622225ed.tar.gz",

demo/src/app/views/inertia/_head.zmpl

@@ -0,0 +1 @@
+<title>My Inertia App</title>

demo/src/main.zig

@@ -14,7 +14,8 @@ pub const jetzig_options = struct {
     pub const middleware: []const type = &.{
         // jetzig.middleware.AuthMiddleware,
         // jetzig.middleware.AntiCsrfMiddleware,
-        // jetzig.middleware.HtmxMiddleware,
+        jetzig.middleware.HtmxMiddleware,
+            // jetzig.middleware.InertiaMiddleware,
             // jetzig.middleware.CompressionMiddleware,
             // @import("app/middleware/DemoMiddleware.zig"),
     };

src/compile_static_routes.zig

@@ -147,7 +147,7 @@ fn renderMarkdown(
 
         if (zmpl.findPrefixed("views", prefixed_name)) |layout| {
             view.data.content = .{ .data = content };
-            return try layout.render(view.data, jetzig.TemplateContext, .{}, .{});
+            return try layout.render(view.data, jetzig.TemplateContext, .{}, &.{}, .{});
         } else {
             std.debug.print("Unknown layout: {s}\n", .{layout_name});
             return content;
@@ -174,6 +174,7 @@ fn renderZmplTemplate(
                     view.data,
                     jetzig.TemplateContext,
                     .{},
+                    &.{},
                     .{ .layout = layout },
                 );
             } else {
@@ -181,7 +182,7 @@ fn renderZmplTemplate(
                 return try allocator.dupe(u8, "");
             }
         } else {
-            return try template.render(view.data, jetzig.TemplateContext, .{}, .{});
+            return try template.render(view.data, jetzig.TemplateContext, .{}, &.{}, .{});
         }
     } else return null;
 }

src/jetzig/TemplateContext.zig

@@ -1,13 +1,18 @@
 const std = @import("std");
 
 pub const http = @import("http.zig");
+pub const views = @import("views.zig");
 pub const config = @import("config.zig");
 
 /// Context available in every Zmpl template as `context`.
 pub const TemplateContext = @This();
 
 request: ?*http.Request = null,
+route: ?views.Route = null,
 
+/// Return an authenticity token stored in the current request's session. If no token exists,
+/// generate and store before returning.
+/// Use to create a form element which can be verified by `AntiCsrfMiddleware`.
 pub fn authenticityToken(self: TemplateContext) !?[]const u8 {
     return if (self.request) |request|
         try request.authenticityToken()
@@ -15,6 +20,8 @@ pub fn authenticityToken(self: TemplateContext) !?[]const u8 {
         null;
 }
 
+/// Generate a hidden form element containing an authenticity token provided by
+/// `authenticityToken`. Use as `{{context.authenticityFormElement()}}` in a Zmpl template.
 pub fn authenticityFormElement(self: TemplateContext) !?[]const u8 {
     return if (self.request) |request| blk: {
         const token = try request.authenticityToken();
@@ -23,3 +30,10 @@ pub fn authenticityFormElement(self: TemplateContext) !?[]const u8 {
         , .{ config.get([]const u8, "authenticity_token_name"), token });
     } else null;
 }
+
+pub fn path(self: TemplateContext) ?[]const u8 {
+    return if (self.request) |request|
+        request.path.path
+    else
+        null;
+}

src/jetzig/http/Request.zig

@@ -15,6 +15,7 @@ pub const RequestState = enum {
     initial, // No processing has taken place
     processed, // Request headers have been processed
     after_request, // Initial middleware processing
+    after_view, // View returned, response data ready for full response render
     rendered, // Rendered by middleware or view
     redirected, // Redirected by middleware or view
     failed, // Failed by middleware or view
@@ -217,6 +218,20 @@ pub fn render(self: *Request, status_code: jetzig.http.status_codes.StatusCode)
     return self.rendered_view.?;
 }
 
+/// Render a response with pre-rendered content. This function can only be called once per
+/// request (repeat calls will trigger an error).
+pub fn renderContent(
+    self: *Request,
+    status_code: jetzig.http.status_codes.StatusCode,
+    content: []const u8,
+) jetzig.views.View {
+    if (self.isRendered()) self.rendered_multiple = true;
+
+    self.state = .rendered;
+    self.rendered_view = .{ .data = self.response_data, .status_code = status_code, .content = content };
+    return self.rendered_view.?;
+}
+
 /// Render an error. This function can only be called once per request (repeat calls will
 /// trigger an error).
 pub fn fail(self: *Request, status_code: jetzig.http.status_codes.StatusCode) jetzig.views.View {
@@ -230,7 +245,7 @@ pub fn fail(self: *Request, status_code: jetzig.http.status_codes.StatusCode) je
 pub inline fn isRendered(self: *const Request) bool {
     return switch (self.state) {
         .initial, .processed, .after_request, .before_response => false,
-        .rendered, .redirected, .failed, .finalized => true,
+        .after_view, .rendered, .redirected, .failed, .finalized => true,
     };
 }
 
@@ -306,6 +321,7 @@ pub fn renderRedirect(self: *Request, state: RedirectState) !void {
                 self.response_data,
                 jetzig.TemplateContext,
                 .{ .request = self },
+                &.{},
                 .{},
             );
         } else try std.fmt.allocPrint(self.allocator, "Redirecting to {s}", .{state.location}),

src/jetzig/http/Server.zig

@@ -152,13 +152,18 @@ pub fn processNextRequest(
 
     try request.process();
 
+    // Allow middleware to render templates even though we have not mapped a view/action yet.
+    // TODO: We should probably separate the routing and map routes before we invoke middleware.
+    try request.response_data.addConst("jetzig_action", request.response_data.string(""));
+    try request.response_data.addConst("jetzig_view", request.response_data.string(""));
+
     var middleware_data = try jetzig.http.middleware.afterRequest(&request);
     if (try maybeMiddlewareRender(&request, &response)) {
         try self.logger.logRequest(&request);
         return;
     }
 
-    try self.renderResponse(&request);
+    try self.renderResponse(&request, &middleware_data);
     try request.response.headers.append("Content-Type", response.content_type);
 
     try jetzig.http.middleware.beforeResponse(&middleware_data, &request);
@@ -175,8 +180,7 @@ fn maybeMiddlewareRender(request: *jetzig.http.Request, response: *const jetzig.
         if (request.redirect_state) |state| {
             try request.renderRedirect(state);
         } else if (request.rendered_view) |rendered| {
-            // TODO: Allow middleware to set content
+            request.setResponse(.{ .view = rendered, .content = rendered.content orelse "" }, .{});
-            request.setResponse(.{ .view = rendered, .content = "" }, .{});
         }
         try request.response.headers.append("Content-Type", response.content_type);
         try request.respond();
@@ -184,7 +188,11 @@ fn maybeMiddlewareRender(request: *jetzig.http.Request, response: *const jetzig.
     } else return false;
 }
 
-fn renderResponse(self: *Server, request: *jetzig.http.Request) !void {
+fn renderResponse(
+    self: *Server,
+    request: *jetzig.http.Request,
+    middleware_data: *jetzig.http.middleware.MiddlewareData,
+) !void {
     const static_resource = self.matchStaticResource(request) catch |err| {
         if (isUnhandledError(err)) return err;
 
@@ -236,6 +244,34 @@ fn renderResponse(self: *Server, request: *jetzig.http.Request) !void {
                 return;
             }
         }
+
+        // View functions return a `View` to encourage users to return from a view function with
+        // `return request.render(.ok)`, but the actual rendered view is stored in
+        // `request.rendered_view`.
+        _ = route.render(route, request) catch |err| {
+            if (isUnhandledError(err)) return err;
+            const rendered_error = if (isBadRequest(err))
+                try self.renderBadRequest(request)
+            else
+                try self.renderInternalServerError(request, @errorReturnTrace(), err);
+            request.setResponse(rendered_error, .{});
+            return;
+        };
+
+        if (request.rendered_view != null) {
+            try jetzig.http.middleware.afterView(middleware_data, request, route);
+        }
+    }
+
+    if (request.middleware_rendered) |_| {
+        // Request processing ends when a middleware renders or redirects.
+        if (request.redirect_state) |state| {
+            try request.renderRedirect(state);
+        } else if (request.rendered_view) |rendered| {
+            request.setResponse(.{ .view = rendered, .content = rendered.content orelse "" }, .{});
+        }
+        try request.response.headers.append("Content-Type", request.response.content_type);
+        return try request.respond();
     }
 
     switch (request.requestFormat()) {
@@ -347,15 +383,6 @@ fn renderView(
     request: *jetzig.http.Request,
     maybe_template: ?zmpl.Template,
 ) !RenderedView {
-    // View functions return a `View` to encourage users to return from a view function with
-    // `return request.render(.ok)`, but the actual rendered view is stored in
-    // `request.rendered_view`.
-    _ = route.render(route, request) catch |err| {
-        if (isUnhandledError(err)) return err;
-        if (isBadRequest(err)) return try self.renderBadRequest(request);
-        return try self.renderInternalServerError(request, @errorReturnTrace(), err);
-    };
-
     if (request.state == .failed) {
         const view: jetzig.views.View = request.rendered_view orelse .{
             .data = request.response_data,
@@ -415,7 +442,7 @@ fn renderTemplateWithLayout(
 ) ![]const u8 {
     try addTemplateConstants(view, route);
 
-    const template_context = jetzig.TemplateContext{ .request = request };
+    const template_context = jetzig.TemplateContext{ .request = request, .route = route };
 
     if (request.getLayout(route)) |layout_name| {
         // TODO: Allow user to configure layouts directory other than src/app/views/layouts/
@@ -431,6 +458,7 @@ fn renderTemplateWithLayout(
                 view.data,
                 jetzig.TemplateContext,
                 template_context,
+                &.{},
                 .{ .layout = layout },
             );
         } else {
@@ -439,6 +467,7 @@ fn renderTemplateWithLayout(
                 view.data,
                 jetzig.TemplateContext,
                 template_context,
+                &.{},
                 .{},
             );
         }
@@ -446,6 +475,7 @@ fn renderTemplateWithLayout(
         view.data,
         jetzig.TemplateContext,
         template_context,
+        &.{},
         .{},
     );
 }
@@ -608,7 +638,8 @@ fn renderErrorView(
                                 .content = try template.render(
                                     request.response_data,
                                     jetzig.TemplateContext,
-                                    .{ .request = request },
+                                    .{ .request = request, .route = route.* },
+                                    &.{},
                                     .{},
                                 ),
                             };

src/jetzig/http/middleware.zig

@@ -94,6 +94,38 @@ pub fn afterRequest(request: *jetzig.http.Request) !MiddlewareData {
     return middleware_data;
 }
 
+pub fn afterView(middleware_data: *MiddlewareData, request: *jetzig.http.Request, route: jetzig.views.Route) !void {
+    if (request.state != .failed) request.state = .after_view;
+
+    inline for (middlewares, 0..) |middleware, index| {
+        if (comptime !@hasDecl(middleware, "afterView")) continue;
+        if (request.state == .after_view) {
+            if (comptime @hasDecl(middleware, "init")) {
+                const data = middleware_data.get(index).?;
+                try @call(
+                    .always_inline,
+                    middleware.afterView,
+                    .{ @as(*middleware, @ptrCast(@alignCast(data))), request, route },
+                );
+            } else {
+                try @call(
+                    .always_inline,
+                    middleware.afterView,
+                    .{ request, route },
+                );
+            }
+        }
+
+        if (request.state != .after_view) {
+            request.middleware_rendered = .{
+                .name = @typeName(middleware),
+                .action = "afterView",
+            };
+            break;
+        }
+    }
+}
+
 pub fn beforeResponse(
     middleware_data: *MiddlewareData,
     request: *jetzig.http.Request,

src/jetzig/mail/Job.zig

@@ -148,7 +148,7 @@ fn defaultHtml(
     try data.addConst("jetzig_view", data.string(""));
     try data.addConst("jetzig_action", data.string(""));
     return if (jetzig.zmpl.findPrefixed("mailers", mailer.html_template)) |template|
-        try template.render(&data, jetzig.TemplateContext, .{}, .{})
+        try template.render(&data, jetzig.TemplateContext, .{}, &.{}, .{})
     else
         null;
 }
@@ -166,7 +166,7 @@ fn defaultText(
     try data.addConst("jetzig_view", data.string(""));
     try data.addConst("jetzig_action", data.string(""));
     return if (jetzig.zmpl.findPrefixed("mailers", mailer.text_template)) |template|
-        try template.render(&data, jetzig.TemplateContext, .{}, .{})
+        try template.render(&data, jetzig.TemplateContext, .{}, &.{}, .{})
     else
         null;
 }

src/jetzig/middleware.zig

@@ -5,6 +5,7 @@ pub const HtmxMiddleware = @import("middleware/HtmxMiddleware.zig");
 pub const CompressionMiddleware = @import("middleware/CompressionMiddleware.zig");
 pub const AuthMiddleware = @import("middleware/AuthMiddleware.zig");
 pub const AntiCsrfMiddleware = @import("middleware/AntiCsrfMiddleware.zig");
+pub const InertiaMiddleware = @import("middleware/InertiaMiddleware.zig");
 
 const RouteOptions = struct {
     content: ?[]const u8 = null,

src/jetzig/middleware/InertiaMiddleware.zig

@@ -0,0 +1,6 @@
+const std = @import("std");
+const jetzig = @import("../../jetzig.zig");
+
+// WIP
+
+const InertiaMiddleware = @This();

src/jetzig/templates/inertia.zmpl

@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    @partial views:inertia/head
+  </head>
+  <body>
+    <div
+      id="app"
+      data-page='{"component":"{{jetzig_view}}","props":{{zmpl.toJson()}},"url":"{{context.path()}}","version":"c32b8e4965f418ad16eaebba1d4e960f"}'
+    >
+    </div>
+  </body>
+</html>

src/jetzig/views/View.zig

@@ -6,6 +6,7 @@ const jetzig = @import("../../jetzig.zig");
 
 data: *jetzig.data.Data,
 status_code: jetzig.http.status_codes.StatusCode = .ok,
+content: ?[]const u8 = null,
 
 pub fn deinit(self: Self) void {
     _ = self;