Skip to main content
Version: Next

Literals and Expressions

Literals

If expressions resolve to types that implement Display, they will be converted to strings and inserted into the DOM as a Text node.

note

String literals create Text nodes, which are treated as strings by the browser. Hence, even if the expression contains a <script> tag you can't fall for XSS and such security issues, unless of course you wrap the expression in a <script> block.

All display text must be enclosed by {} blocks because the text is handled as an expression. This is the largest deviation from normal HTML syntax that Yew makes.

use yew::prelude::*;

let text = "lorem ipsum";
html!{
<>
<div>{text}</div>
<div>{"dolor sit"}</div>
<span>{42}</span>
</>
};

Expressions

You can insert expressions in your HTML using {} blocks, as long as they resolve to Html

use yew::prelude::*;

let show_link = true;

html! {
<div>
{
if show_link {
html! {
<a href="https://example.com">{"Link"}</a>
}
} else {
html! {}
}
}
</div>
};

It often makes sense to extract these expressions into functions or closures to optimize for readability:

use yew::prelude::*;

let show_link = true;
let maybe_display_link = move || -> Html {
if show_link {
html! {
<a href="https://example.com">{"Link"}</a>
}
} else {
html! {}
}
};

html! {
<div>{maybe_display_link()}</div>
};