add ai and todo example templates for native frontends (#293)

apps/cli/templates/examples/ai/native/nativewind/app/(drawer)/ai.tsx.hbs

@@ -0,0 +1,155 @@
+import { useRef, useEffect } from "react";
+import {
+  View,
+  Text,
+  TextInput,
+  TouchableOpacity,
+  ScrollView,
+  KeyboardAvoidingView,
+  Platform,
+} from "react-native";
+import { useChat } from "@ai-sdk/react";
+import { fetch as expoFetch } from "expo/fetch";
+import { Ionicons } from "@expo/vector-icons";
+import { Container } from "@/components/container";
+
+// Utility function to generate API URLs
+const generateAPIUrl = (relativePath: string) => {
+  const serverUrl = process.env.EXPO_PUBLIC_SERVER_URL;
+  if (!serverUrl) {
+    throw new Error("EXPO_PUBLIC_SERVER_URL environment variable is not defined");
+  }
+  
+  const path = relativePath.startsWith('/') ? relativePath : `/${relativePath}`;
+  return serverUrl.concat(path);
+};
+
+export default function AIScreen() {
+  const { messages, input, handleInputChange, handleSubmit, error } = useChat({
+    fetch: expoFetch as unknown as typeof globalThis.fetch,
+    api: generateAPIUrl('/ai'),
+    onError: error => console.error(error, 'AI Chat Error'),
+    maxSteps: 5,
+  });
+
+  const scrollViewRef = useRef<ScrollView>(null);
+
+  useEffect(() => {
+    scrollViewRef.current?.scrollToEnd({ animated: true });
+  }, [messages]);
+
+  const onSubmit = () => {
+    if (input.trim()) {
+      handleSubmit();
+    }
+  };
+
+  if (error) {
+    return (
+      <Container>
+        <View className="flex-1 justify-center items-center px-4">
+          <Text className="text-destructive text-center text-lg mb-4">
+            Error: {error.message}
+          </Text>
+          <Text className="text-muted-foreground text-center">
+            Please check your connection and try again.
+          </Text>
+        </View>
+      </Container>
+    );
+  }
+
+  return (
+    <Container>
+      <KeyboardAvoidingView 
+        className="flex-1"
+        behavior={Platform.OS === "ios" ? "padding" : "height"}
+      >
+        <View className="flex-1 px-4 py-6">
+          <View className="mb-6">
+            <Text className="text-foreground text-2xl font-bold mb-2">
+              AI Chat
+            </Text>
+            <Text className="text-muted-foreground">
+              Chat with our AI assistant
+            </Text>
+          </View>
+
+          <ScrollView
+            ref={scrollViewRef}
+            className="flex-1 mb-4"
+            showsVerticalScrollIndicator={false}
+          >
+            {messages.length === 0 ? (
+              <View className="flex-1 justify-center items-center">
+                <Text className="text-center text-muted-foreground text-lg">
+                  Ask me anything to get started!
+                </Text>
+              </View>
+            ) : (
+              <View className="space-y-4">
+                {messages.map((message) => (
+                  <View
+                    key={message.id}
+                    className={`p-3 rounded-lg ${
+                      message.role === "user"
+                        ? "bg-primary/10 ml-8"
+                        : "bg-card mr-8 border border-border"
+                    }`}
+                  >
+                    <Text className="text-sm font-semibold mb-1 text-foreground">
+                      {message.role === "user" ? "You" : "AI Assistant"}
+                    </Text>
+                    <Text className="text-foreground leading-relaxed">
+                      {message.content}
+                    </Text>
+                  </View>
+                ))}
+              </View>
+            )}
+          </ScrollView>
+
+          <View className="border-t border-border pt-4">
+            <View className="flex-row items-end space-x-2">
+              <TextInput
+                value={input}
+                onChange={(e) =>
+                  handleInputChange({
+                    ...e,
+                    target: {
+                      ...e.target,
+                      value: e.nativeEvent.text,
+                    },
+                  } as unknown as React.ChangeEvent<HTMLInputElement>)
+                }
+                placeholder="Type your message..."
+                placeholderTextColor="#6b7280"
+                className="flex-1 border border-border rounded-md px-3 py-2 text-foreground bg-background min-h-[40px] max-h-[120px]"
+                onSubmitEditing={(e) => {
+                  handleSubmit(e);
+                  e.preventDefault();
+                }}
+                autoFocus={true}
+              />
+              <TouchableOpacity
+                onPress={onSubmit}
+                disabled={!input.trim()}
+                className={`p-2 rounded-md ${
+                  input.trim() 
+                    ? "bg-primary" 
+                    : "bg-muted"
+                }`}
+              >
+                <Ionicons
+                  name="send"
+                  size={20}
+                  color={input.trim() ? "#ffffff" : "#6b7280"}
+                />
+              </TouchableOpacity>
+            </View>
+          </View>
+        </View>
+      </KeyboardAvoidingView>
+    </Container>
+  );
+} 

apps/cli/templates/examples/ai/native/nativewind/polyfills.js

@@ -0,0 +1,25 @@
+import structuredClone from "@ungap/structured-clone";
+import { Platform } from "react-native";
+
+if (Platform.OS !== "web") {
+  const setupPolyfills = async () => {
+    const { polyfillGlobal } = await import(
+      "react-native/Libraries/Utilities/PolyfillFunctions"
+    );
+
+    const { TextEncoderStream, TextDecoderStream } = await import(
+      "@stardazed/streams-text-encoding"
+    );
+
+    if (!("structuredClone" in global)) {
+      polyfillGlobal("structuredClone", () => structuredClone);
+    }
+
+    polyfillGlobal("TextEncoderStream", () => TextEncoderStream);
+    polyfillGlobal("TextDecoderStream", () => TextDecoderStream);
+  };
+
+  setupPolyfills();
+}
+
+export {};