sailfish/docs/en/docs/syntax/tags.md

Tags

Code block

You can write Rust statement inside <% %> tag.

=== "Template"

``` rhtml
<%
let mut total = 0;
for i in 1.. {
    total += i;
    if i > 100 {
        break;
    }
}
%>
<div>total = <%\html total %></div>
```

=== "Result"

``` html
<div>total = 105</div>
```

!!! Note Make sure that you cannot omit braces, parenthesis, and semicolons.

Sailfish is smart enough to figure out where the code block ends, so you can even include %> inside Rust comments or string literals.

=== "Template"

``` text
<% /* Tag does not ends at %>! */ %>
```

=== "Result"

``` text
```

If you need to simply render <% character, you can escape it, or use evaluation block (described below).

=== "Template"

``` text
<%% is converted into <%- "<%" %> character.
```

=== "Result"

``` text
<% is converted into <% character
```

Although almost all Rust statement is supported, the following statements inside templates may cause a strange compilation error.

• Function/Macro definition that render some contents
• impl item
• Macro call which defines some local variable.
• Macro call which behaviour depends on the path to source file
• Generator expression (yield)

Evaluation block

Rust expression inside <%\mode %> tag is evaluated and the result will be rendered.

=== "Template"

``` rhtml
<% let a = 1; %><%\html a + 2 %>
```

=== "Result"

``` text
3
```

If the result contains &"'<> characters, sailfish replaces these characters with the equivalent html.

If you want to render the results without escaping, you can use <%- %> tag.

=== "Template"

``` rhtml
<div>
  <%- "<h1>Hello, World!</h1>" %>
</div>
```

=== "Result"

``` html
<div>
  <h1>Hello, World!</h1>
</div>
```

!!! Note Evaluation block does not return any value, so you cannot use the block to pass the render result to another code block. The following code is invalid.

``` rhtml
<% let result = %><%\html 1 %><% ; %>
```