rocket_dyn_templates/
fairing.rs

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1use rocket::{Rocket, Build, Orbit};
2use rocket::fairing::{self, Fairing, Info, Kind};
3use rocket::figment::{Source, value::magic::RelativePathBuf};
4use rocket::trace::Trace;
5
6use crate::context::{Callback, Context, ContextManager};
7use crate::template::DEFAULT_TEMPLATE_DIR;
8use crate::engine::Engines;
9
10/// The TemplateFairing initializes the template system on attach, running
11/// custom_callback after templates have been loaded. In debug mode, the fairing
12/// checks for modifications to templates before every request and reloads them
13/// if necessary.
14pub struct TemplateFairing {
15    /// The user-provided customization callback, allowing the use of
16    /// functionality specific to individual template engines. In debug mode,
17    /// this callback might be run multiple times as templates are reloaded.
18    pub callback: Callback,
19}
20
21#[rocket::async_trait]
22impl Fairing for TemplateFairing {
23    fn info(&self) -> Info {
24        let kind = Kind::Ignite | Kind::Liftoff;
25        #[cfg(debug_assertions)] let kind = kind | Kind::Request;
26
27        Info { kind, name: "Templating" }
28    }
29
30    /// Initializes the template context. Templates will be searched for in the
31    /// `template_dir` config variable or the default ([DEFAULT_TEMPLATE_DIR]).
32    /// The user's callback, if any was supplied, is called to customize the
33    /// template engines. In debug mode, the `ContextManager::new` method
34    /// initializes a directory watcher for auto-reloading of templates.
35    async fn on_ignite(&self, rocket: Rocket<Build>) -> fairing::Result {
36        let configured_dir = rocket.figment()
37            .extract_inner::<RelativePathBuf>("template_dir")
38            .map(|path| path.relative());
39
40        let path = match configured_dir {
41            Ok(dir) => dir,
42            Err(e) if e.missing() => DEFAULT_TEMPLATE_DIR.into(),
43            Err(e) => {
44                e.trace_error();
45                return Err(rocket);
46            }
47        };
48
49        if let Some(ctxt) = Context::initialize(&path, &self.callback) {
50            Ok(rocket.manage(ContextManager::new(ctxt)))
51        } else {
52            error!("Template initialization failed. Aborting launch.");
53            Err(rocket)
54        }
55    }
56
57    async fn on_liftoff(&self, rocket: &Rocket<Orbit>) {
58        let cm = rocket.state::<ContextManager>()
59            .expect("Template ContextManager registered in on_ignite");
60
61        span_info!("templating" => {
62            info!(directory = %Source::from(&*cm.context().root));
63            info!(engines = ?Engines::ENABLED_EXTENSIONS);
64        });
65    }
66
67    #[cfg(debug_assertions)]
68    async fn on_request(&self, req: &mut rocket::Request<'_>, _data: &mut rocket::Data<'_>) {
69        let cm = req.rocket().state::<ContextManager>()
70            .expect("Template ContextManager registered in on_ignite");
71
72        cm.reload_if_needed(&self.callback);
73    }
74}
rocket_dyn_templates/fairing.rs

rocket_dyn_templates/
fairing.rs
