Makepad Splash Skill

> Version: makepad-widgets (dev branch) | Last Updated: 2026-01-19 > > Check for updates: https://crates.io/crates/makepad-widgets

You are an expert at Makepad Splash scripting language. Help users by:

• Writing Splash scripts: Dynamic UI and workflow automation
• Understanding Splash: Purpose, syntax, and capabilities

When to Use

• You need dynamic scripting inside Makepad using Splash.
• The task involves script!, cx.eval, runtime-generated UI, or workflow automation in Makepad.
• You want guidance on Splash syntax and purpose rather than static Rust-only patterns.

Documentation

Refer to the local files for detailed documentation:

• ./references/splash-tutorial.md - Splash language tutorial

IMPORTANT: Documentation Completeness Check

Before answering questions, Claude MUST:

1. Read the relevant reference file(s) listed above
2. If file read fails or file is empty:

• Inform user: "本地文档不完整，建议运行 /sync-crate-skills makepad --force 更新文档"
• Still answer based on SKILL.md patterns + built-in knowledge

1. If reference file exists, incorporate its content into the answer

What is Splash?

Splash is Makepad's dynamic scripting language designed for:

• AI-assisted workflows
• Dynamic UI generation
• Rapid prototyping
• HTTP requests and async operations

Script Macro

rust
// Embed Splash code in Rust
script!{
    fn main() {
        let x = 10;
        console.log("Hello from Splash!");
    }
}

Execution

rust
// Evaluate Splash code at runtime
cx.eval(code_string); // security-allowlist: Makepad runtime API; require trusted code_string

// With context
cx.eval_with_context(code, context);

Basic Syntax

Variables

splash
let x = 10;
let name = "Makepad";
let items = [1, 2, 3];
let config = { width: 100, height: 50 };

Functions

splash
fn add(a, b) {
    return a + b;
}

fn greet(name) {
    console.log("Hello, " + name);
}

Control Flow

splash
// If-else
if x > 10 {
    console.log("big");
} else {
    console.log("small");
}

// Loops
for i in 0..10 {
    console.log(i);
}

while condition {
    // ...
}

Built-in Objects

console

splash
console.log("Message");
console.warn("Warning");
console.error("Error");

http

splash
// GET request
let response = http.get("https://api.example.com/data");

// POST request
let response = http.post("https://api.example.com/data", {
    body: { key: "value" }
});

timer

splash
// Set timeout
timer.set(1000, fn() {
    console.log("1 second passed");
});

// Set interval
let id = timer.interval(500, fn() {
    console.log("tick");
});

// Clear timer
timer.clear(id);

Widget Interaction

splash
// Access widgets
let button = ui.widget("my_button");
button.set_text("Click Me");
button.set_visible(true);

// Listen to events
button.on_click(fn() {
    console.log("Button clicked!");
});

Async Operations

splash
// Async function
async fn fetch_data() {
    let response = await http.get("https://api.example.com");
    return response.json();
}

// Call async
fetch_data().then(fn(data) {
    console.log(data);
});

AI Workflow Integration

Splash is designed for AI-assisted development:

splash
// Dynamic UI generation
fn create_form(fields) {
    let form = ui.create("View");
    for field in fields {
        let input = ui.create("TextInput");
        input.set_label(field.label);
        form.add_child(input);
    }
    return form;
}

// AI can generate this dynamically
create_form([
    { label: "Name" },
    { label: "Email" },
    { label: "Message" }
]);

Use Cases

1. Rapid Prototyping: Quickly test UI layouts without recompilation
2. AI Agents: Let AI generate and modify UI dynamically
3. Configuration: Runtime configuration of app behavior
4. Scripted Workflows: Automate repetitive tasks
5. Plugin System: Extend app functionality with scripts

When Answering Questions

1. Splash is for dynamic/runtime scripting, not core app logic
2. Use Rust for performance-critical code, Splash for flexibility
3. Splash syntax is similar to JavaScript/Rust hybrid
4. Scripts run in a sandboxed environment
5. HTTP and timer APIs enable async operations

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.