Rocal UI - A simple template engine with Rust

Although this template engine is basically intended to use with Rocal framework to craft views, it can be used anywhere with Rust.

Let's begin with syntax of Rocal UI. Here is a simple example including variables, if-else control, and for-loop control.

view! {
  <div class="container">
    <h1 class="title">{ title }</h1>

    if user.id <= 10 {
      <p>{ "You are an early user!" }</p>
      <a href={ reward_url }>{ "Click here to get rewards!" }</a>
    } else if user.id <= 20 {
      <p>{ "You are kind of an early user." }</p>
      <a href={ sort_of_reward_url }>{ "Check it out for your reward." }</a>
    } else {
      <p>{ "You are a regular user." }</p>
    }

    <hr/>
    
    <ul>
      for article in articles {
        <li><a href={ article.url }>{ article.title }</a></li>
      }
    </ul>
  </div>
}

It's straight forward, isn't it?

• { variable }: You can set a variable that returns &str and it will be sanitized HTML safe.
• {{ variable }} : You can set a variable that returns &str but it will NOT sanitized HTML safe. So maybe you could use it to embed a safe HTML.
• if-else : you can utilize if-else even else-if as below

if user.id <= 10 {
    <p>{ "You are an early user!" }</p>
    <a href={{ reward_url }}>{ "Click here to get rewards!" }</a>
} else if user.id <= 20 {
   <p>{ "You are kind of an early user." }</p>
   <a href={{ sort_of_reward_url }}>{ "Check it out for your reward." }</a>
} else {
  <p>{ "You are a regular user." }</p>
}

• for-in: This can be used as same as Rust syntax

for article in articles {
  <li><a href={{ article.url }}>{{ article.title }}</a></li>
}

Advanced use

view! {} produces HTML string technically, so you can embed view! in another view! like using it as a partial template.

let button = view! {
  <button type="submit" class="btn btn-primary">
    Submit
  </button>
};

view! {
  <form action={{ &format!("/articles/{}", article.id) }}>
    <input type="text" />
    {{ &button }}
  </form>
}

On top of that, so {{ variable }} can take any expression that emits &str of Rust, if you want to do string interpolation, you can write like {{ &format!("Hi, {}", name) }}.

How to install

// Cargo.toml
rocal-macro = { version = [LATEST_VERSION], default-features = false, features = ["ui"] }

OR

(if you have not had cargo yet, follow this link first)

$ cargo install rocal --features="cli"
$ rocal new -n yourapp

Then in yourapp/src/templates/root_template.rs, you could see an example of usage of Rocal UI

Links

• GitHub I'd appreciate it if you could star it.
• Download