Struct rocket_contrib::templates::Metadata
source · pub struct Metadata<'a>(/* private fields */);
Expand description
Request guard for dynamiclly querying template metadata.
§Usage
The Metadata
type implements Rocket’s FromRequest
trait, so it can be
used as a request guard in any request handler.
use rocket_contrib::templates::{Template, Metadata};
#[get("/")]
fn homepage(metadata: Metadata) -> Template {
// Conditionally render a template if it's available.
if metadata.contains_template("some-template") {
Template::render("some-template", &context)
} else {
Template::render("fallback", &context)
}
}
fn main() {
rocket::ignite()
.attach(Template::fairing())
// ...
}
Implementations§
source§impl<'a> Metadata<'a>
impl<'a> Metadata<'a>
sourcepub fn contains_template(&self, name: &str) -> bool
pub fn contains_template(&self, name: &str) -> bool
Returns true
if the template with the given name
is currently
loaded. Otherwise, returns false
.
§Example
use rocket_contrib::templates::Metadata;
#[get("/")]
fn handler(metadata: Metadata) {
// Returns `true` if the template with name `"name"` was loaded.
let loaded = metadata.contains_template("name");
}
Trait Implementations§
source§impl<'a, 'r> FromRequest<'a, 'r> for Metadata<'a>
impl<'a, 'r> FromRequest<'a, 'r> for Metadata<'a>
Retrieves the template metadata. If a template fairing hasn’t been attached,
an error is printed and an empty Err
with status InternalServerError
(500
) is returned.
Auto Trait Implementations§
impl<'a> Freeze for Metadata<'a>
impl<'a> RefUnwindSafe for Metadata<'a>
impl<'a> Send for Metadata<'a>
impl<'a> Sync for Metadata<'a>
impl<'a> Unpin for Metadata<'a>
impl<'a> UnwindSafe for Metadata<'a>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
§impl<T> IntoCollection<T> for T
impl<T> IntoCollection<T> for T
source§impl<T> IntoSql for T
impl<T> IntoSql for T
source§fn into_sql<T>(self) -> Self::Expressionwhere
Self: Sized + AsExpression<T>,
fn into_sql<T>(self) -> Self::Expressionwhere
Self: Sized + AsExpression<T>,
Convert
self
to an expression for Diesel’s query builder. Read moresource§fn as_sql<'a, T>(&'a self) -> <&'a Self as AsExpression<T>>::Expressionwhere
&'a Self: AsExpression<T>,
fn as_sql<'a, T>(&'a self) -> <&'a Self as AsExpression<T>>::Expressionwhere
&'a Self: AsExpression<T>,
Convert
&self
to an expression for Diesel’s query builder. Read more