JS RPC

demo/public/party.css

@@ -114,3 +114,9 @@ body {
 .trophy {
   font-size: 5rem;
 }
+#victor {
+  margin: 3rem;
+  font-size: 5rem;
+  text-align: center;
+  vertical-align: center;
+}

demo/src/app/lib/Game.zig

@@ -0,0 +1,83 @@
+const std = @import("std");
+const jetzig = @import("jetzig");
+
+grid: Grid,
+victor: ?State = null,
+
+pub const Grid = [9]State;
+pub const State = enum { empty, player, cpu, tie };
+
+const Game = @This();
+
+pub fn gridFromValues(values: []*jetzig.data.Value) Grid {
+    var grid: [9]Game.State = undefined;
+    for (0..9) |id| {
+        if (values[id].* != .null) {
+            grid[id] = if (values[id].eql("player")) .player else .cpu;
+        } else {
+            grid[id] = .empty;
+        }
+    }
+    return grid;
+}
+
+pub fn movePlayer(game: *Game, cell: usize) bool {
+    if (cell >= game.grid.len) return false;
+    if (game.grid[cell] != .empty) return false;
+
+    game.grid[cell] = .player;
+    game.evaluate();
+    return true;
+}
+
+pub fn moveCpu(game: *Game) usize {
+    std.debug.assert(game.victor == null);
+    var available: [9]usize = undefined;
+    var available_len: usize = 0;
+    for (game.grid, 0..) |cell, cell_index| {
+        if (cell == .empty) {
+            available[available_len] = cell_index;
+            available_len += 1;
+        }
+    }
+    std.debug.assert(available_len > 0);
+    const choice = available[std.crypto.random.intRangeAtMost(usize, 0, available_len - 1)];
+    game.grid[choice] = .cpu;
+    game.evaluate();
+    return choice;
+}
+
+pub fn evaluate(game: *Game) void {
+    var full = true;
+    for (game.grid) |cell| {
+        if (cell == .empty) full = false;
+    }
+    if (full) {
+        game.victor = .tie;
+        return;
+    }
+
+    const patterns = [_][3]usize{
+        .{ 0, 1, 2 },
+        .{ 3, 4, 5 },
+        .{ 6, 7, 8 },
+        .{ 0, 3, 6 },
+        .{ 1, 4, 7 },
+        .{ 2, 5, 8 },
+        .{ 0, 4, 8 },
+        .{ 2, 4, 6 },
+    };
+    for (patterns) |pattern| {
+        var cpu_victor = true;
+        var player_victor = true;
+
+        for (pattern) |cell_index| {
+            if (game.grid[cell_index] != .cpu) cpu_victor = false;
+            if (game.grid[cell_index] != .player) player_victor = false;
+        }
+
+        std.debug.assert(!(cpu_victor and player_victor));
+        if (cpu_victor) game.victor = .cpu;
+        if (player_victor) game.victor = .player;
+    }
+}

demo/src/app/views/websockets.zig

@@ -1,6 +1,8 @@
 const std = @import("std");
 const jetzig = @import("jetzig");
 
+const Game = @import("../lib/Game.zig");
+
 pub fn index(request: *jetzig.Request) !jetzig.View {
     return request.render(.ok);
 }
@@ -11,56 +13,22 @@ pub const Channel = struct {
         try channel.sync();
     }
 
-    pub fn receive(message: jetzig.channels.Message) !void {
-        const params = try message.params() orelse return;
-
-        if (params.remove("reset")) {
-            try resetGame(message.channel);
-            try message.channel.sync();
-            return;
-        }
-
-        const cell: usize = if (params.getT(.integer, "cell")) |integer|
-            @intCast(integer)
-        else
-            return;
-        const cells = message.channel.getT(.array, "cells") orelse return;
-        const items = cells.items();
-
-        var grid: [9]Game.State = undefined;
-        for (0..9) |id| {
-            if (items[id].* != .null) {
-                grid[id] = if (items[id].eql("player")) .player else .cpu;
-            } else {
-                grid[id] = .empty;
-            }
-        }
-
-        var game = Game{ .grid = grid };
-        game.evaluate();
-
-        if (game.winner != null) {
-            try message.channel.publish(.{ .err = "Game is already over." });
-            return;
-        }
-
-        if (game.movePlayer(cell)) {
-            items[cell] = message.data.string("player");
-            if (game.winner == null) {
-                items[game.moveCpu()] = message.data.string("cpu");
-            }
-            if (game.winner) |winner| {
-                try message.channel.put("winner", @tagName(winner));
-                var results = message.channel.getT(.object, "results") orelse return;
-                const count = results.getT(.integer, @tagName(winner)) orelse return;
-                try results.put(@tagName(winner), count + 1);
-            }
-        }
-
-        try message.channel.sync();
-    }
-
     pub const Actions = struct {
+        pub fn move(channel: jetzig.channels.Channel, cell: usize) !void {
+            const cells = channel.getT(.array, "cells") orelse return;
+            const grid = Game.gridFromValues(cells.items());
+            var game = Game{ .grid = grid };
+            game.evaluate();
+
+            if (game.victor != null) {
+                try channel.publish(.{ .err = "Game is already over." });
+                return;
+            } else {
+                try movePlayer(channel, &game, cells, cell);
+                try channel.sync();
+            }
+        }
+
         pub fn reset(channel: jetzig.channels.Channel) !void {
             try resetGame(channel);
             try channel.sync();
@@ -68,7 +36,7 @@ pub const Channel = struct {
     };
 
     fn resetGame(channel: jetzig.channels.Channel) !void {
-        try channel.put("winner", null);
+        try channel.put("victor", null);
         var cells = try channel.put("cells", .array);
         for (0..9) |_| try cells.append(null);
     }
@@ -77,75 +45,31 @@ pub const Channel = struct {
         var results = try channel.put("results", .object);
         try results.put("cpu", 0);
         try results.put("player", 0);
-        try results.put("ties", 0);
+        try results.put("tie", 0);
         try resetGame(channel);
     }
-};
 
-const Game = struct {
-    grid: [9]State,
-    winner: ?State = null,
-
-    pub const State = enum { empty, player, cpu, tie };
-
-    pub fn movePlayer(game: *Game, cell: usize) bool {
-        if (cell >= game.grid.len) return false;
-        if (game.grid[cell] != .empty) return false;
-
-        game.grid[cell] = .player;
-        game.evaluate();
-        return true;
+    fn movePlayer(
+        channel: jetzig.channels.Channel,
+        game: *Game,
+        cells: *const jetzig.data.Array,
+        cell: usize,
+    ) !void {
+        const values = cells.items();
+        if (game.movePlayer(cell)) {
+            values[cell] = channel.data.string("player");
+            if (game.victor == null) {
+                values[game.moveCpu()] = channel.data.string("cpu");
+            }
+            if (game.victor) |victor| try setVictor(channel, victor);
+        }
     }
 
-    pub fn moveCpu(game: *Game) usize {
-        std.debug.assert(game.winner == null);
-        var available: [9]usize = undefined;
-        var available_len: usize = 0;
-        for (game.grid, 0..) |cell, cell_index| {
-            if (cell == .empty) {
-                available[available_len] = cell_index;
-                available_len += 1;
-            }
-        }
-        std.debug.assert(available_len > 0);
-        const choice = available[std.crypto.random.intRangeAtMost(usize, 0, available_len - 1)];
-        game.grid[choice] = .cpu;
-        game.evaluate();
-        return choice;
-    }
-
-    fn evaluate(game: *Game) void {
-        var full = true;
-        for (game.grid) |cell| {
-            if (cell == .empty) full = false;
-        }
-        if (full) {
-            game.winner = .tie;
-            return;
-        }
-
-        const patterns = [_][3]usize{
-            .{ 0, 1, 2 },
-            .{ 3, 4, 5 },
-            .{ 6, 7, 8 },
-            .{ 0, 3, 6 },
-            .{ 1, 4, 7 },
-            .{ 2, 5, 8 },
-            .{ 0, 4, 8 },
-            .{ 2, 4, 6 },
-        };
-        for (patterns) |pattern| {
-            var cpu_winner = true;
-            var player_winner = true;
-
-            for (pattern) |cell_index| {
-                if (game.grid[cell_index] != .cpu) cpu_winner = false;
-                if (game.grid[cell_index] != .player) player_winner = false;
-            }
-
-            std.debug.assert(!(cpu_winner and player_winner));
-            if (cpu_winner) game.winner = .cpu;
-            if (player_winner) game.winner = .player;
-        }
+    fn setVictor(channel: jetzig.channels.Channel, victor: Game.State) !void {
+        try channel.put("victor", @tagName(victor));
+        var results = channel.getT(.object, "results") orelse return;
+        const count = results.getT(.integer, @tagName(victor)) orelse return;
+        try results.put(@tagName(victor), count + 1);
+        try channel.invoke(.victor, .{ .type = @tagName(victor) });
     }
 };

demo/src/app/views/websockets/index.zmpl

@@ -4,8 +4,16 @@
         actions: {},
         stateChangedCallbacks: [],
         messageCallbacks: [],
+        invokeCallbacks: {},
         onStateChanged: function(callback) { this.stateChangedCallbacks.push(callback); },
         onMessage: function(callback) { this.messageCallbacks.push(callback); },
+        receive: function(event, callback) {
+            if (Object.hasOwn(this.invokeCallbacks, event)) {
+                this.invokeCallbacks[event].push(callback);
+            } else {
+                this.invokeCallbacks[event] = [callback];
+            }
+        },
         publish: function(data) {
             if (this.websocket) {
                 const json = JSON.stringify(data);
@@ -22,12 +30,20 @@
             channel.websocket.addEventListener("message", (event) => {
                 const state_tag = "__jetzig_channel_state__:";
                 const actions_tag = "__jetzig_actions__:";
+                const event_tag = "__jetzig_event__:";
 
                 if (event.data.startsWith(state_tag)) {
                     const state = JSON.parse(event.data.slice(state_tag.length));
                     channel.stateChangedCallbacks.forEach((callback) => {
                         callback(state);
                     });
+                } else if (event.data.startsWith(event_tag)) {
+                    const data = JSON.parse(event.data.slice(event_tag.length));
+                    if (Object.hasOwn(channel.invokeCallbacks, data.method)) {
+                        channel.invokeCallbacks[data.method].forEach(callback => {
+                            callback(data);
+                        });
+                    }
                 } else if (event.data.startsWith(actions_tag)) {
                     const data = JSON.parse(event.data.slice(actions_tag.length));
                     data.actions.forEach(action => {
@@ -95,19 +111,20 @@
 
 <button id="reset-button">Reset Game</button>
 
+<div id="victor"></div>
 
 <script src="/party.js"></script>
 <link rel="stylesheet" href="/party.css" />
 
 <script>
     channel.onStateChanged(state => {
-        console.log(state);
         document.querySelector("#player-wins").innerText = state.results.player;
         document.querySelector("#cpu-wins").innerText = state.results.cpu;
-        document.querySelector("#ties").innerText = state.results.ties;
+        document.querySelector("#ties").innerText = state.results.tie;
 
-        if (state.winner) {
-            triggerPartyAnimation();
+        if (!state.victor) {
+            const elem = document.querySelector("#victor");
+            elem.style.visibility = 'hidden';
         }
 
         Object.entries(state.cells).forEach(([cell, state]) => {
@@ -122,13 +139,26 @@
         }
     });
 
+    channel.receive("victor", (data) => {
+        console.log(data);
+        const elem = document.querySelector("#victor");
+        const emoji = {
+            player: "&#9992;&#65039;",
+            cpu: "&#129422;",
+            tie: "&#129309;"
+        }[data.params.type] || "";
+        elem.innerHTML = `&#127942; ${emoji} &#127942;`;
+        elem.style.visibility = 'visible';
+        triggerPartyAnimation();
+    });
+
     document.querySelector("#reset-button").addEventListener("click", () => {
         channel.actions.reset();
     });
 
     document.querySelectorAll("#board div.cell").forEach(element => {
         element.addEventListener("click", () => {
-            channel.publish({ cell: parseInt(element.dataset.cell) });
+            channel.actions.move(parseInt(element.dataset.cell));
         });
     });
 </script>

src/jetzig/channels/Channel.zig

@@ -23,6 +23,32 @@ pub fn RoutedChannel(Routes: type) type {
             const writer = write_buffer.writer();
             try std.json.stringify(data, .{}, writer);
             try write_buffer.flush();
+            channel.websocket.logger.DEBUG(
+                "Published Channel message for `{s}`",
+                .{channel.websocket.route.path},
+            ) catch {};
+        }
+
+        pub fn invoke(
+            channel: Channel,
+            comptime method: @TypeOf(.enum_literal),
+            args: anytype,
+        ) !void {
+            // TODO: DRY
+            var stack_fallback = std.heap.stackFallback(4096, channel.allocator);
+            const allocator = stack_fallback.get();
+
+            var write_buffer = channel.websocket.connection.writeBuffer(allocator, .text);
+            defer write_buffer.deinit();
+
+            const writer = write_buffer.writer();
+            try writer.writeAll("__jetzig_event__:");
+            try std.json.stringify(.{ .method = method, .params = args }, .{}, writer);
+            try write_buffer.flush();
+            channel.websocket.logger.DEBUG(
+                "Invoked Javascript function `{s}` for `{s}`",
+                .{ @tagName(method), channel.websocket.route.path },
+            ) catch {};
         }
 
         pub fn getT(
@@ -45,6 +71,10 @@ pub fn RoutedChannel(Routes: type) type {
             return try channel.state.put(key, value);
         }
 
+        pub fn remove(channel: Channel, key: []const u8) bool {
+            return channel.state.remove(key);
+        }
+
         pub fn sync(channel: Channel) !void {
             try channel.websocket.syncState(channel);
         }