rune/doc/
templating.rs

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1use crate::alloc::borrow::Cow;
2use crate::alloc::prelude::*;
3use crate::alloc::{self, HashMap, String};
4use crate::std::sync::Mutex;
5use ::rust_alloc::sync::Arc;
6
7use handlebars::{
8    Context, Handlebars, Helper, HelperDef, HelperResult, Output, RenderContext, Renderable,
9    StringOutput,
10};
11use serde::Serialize;
12
13use crate::support::Result;
14
15/// A compiled template.
16pub(crate) struct Template {
17    handlebars: Arc<Handlebars<'static>>,
18    template: handlebars::Template,
19}
20
21impl Template {
22    /// Render the current template.
23    pub(crate) fn render<T>(&self, data: &T) -> Result<String>
24    where
25        T: Serialize,
26    {
27        let cx = Context::wraps(data)?;
28        let mut render_context = RenderContext::new(None);
29        let mut out = StringOutput::new();
30        self.template
31            .render(&self.handlebars, &cx, &mut render_context, &mut out)?;
32        Ok(out.into_string()?.try_into()?)
33    }
34}
35
36#[derive(Default, Clone)]
37pub(crate) struct Paths {
38    inner: Arc<Mutex<HashMap<String, String>>>,
39}
40
41impl Paths {
42    /// Insert a path redirect.
43    pub(crate) fn insert(&self, from: &str, to: &str) -> alloc::Result<()> {
44        self.inner
45            .lock()
46            .unwrap()
47            .try_insert(from.try_to_owned()?, to.try_to_owned()?)?;
48        Ok(())
49    }
50}
51
52/// Templating system.
53pub(crate) struct Templating {
54    handlebars: Arc<Handlebars<'static>>,
55}
56
57impl Templating {
58    /// Set up a new templating engine.
59    pub(crate) fn new<'a, I>(partials: I, paths: Paths) -> Result<Templating>
60    where
61        I: IntoIterator<Item = (&'a str, Cow<'a, str>)>,
62    {
63        let mut handlebars = Handlebars::new();
64        handlebars.register_helper("literal", ::rust_alloc::boxed::Box::new(literal));
65        handlebars.register_helper("path", ::rust_alloc::boxed::Box::new(path(paths)));
66
67        for (name, source) in partials {
68            handlebars.register_partial(name, source.as_ref())?;
69        }
70
71        Ok(Templating {
72            handlebars: Arc::new(handlebars),
73        })
74    }
75
76    /// Compile the template.
77    pub(crate) fn compile(&self, source: &str) -> Result<Template> {
78        let template = handlebars::Template::compile(source)?;
79
80        Ok(Template {
81            handlebars: self.handlebars.clone(),
82            template,
83        })
84    }
85}
86
87fn literal(
88    h: &Helper<'_>,
89    _: &Handlebars<'_>,
90    _: &Context,
91    _: &mut RenderContext<'_, '_>,
92    out: &mut dyn Output,
93) -> HelperResult {
94    let param = h.param(0).and_then(|v| v.value().as_str()).unwrap_or("");
95    out.write(param)?;
96    Ok(())
97}
98
99fn path(paths: Paths) -> impl HelperDef + Send + Sync + 'static {
100    move |h: &Helper<'_>,
101          _: &Handlebars<'_>,
102          _: &Context,
103          _: &mut RenderContext<'_, '_>,
104          out: &mut dyn Output|
105          -> HelperResult {
106        let param = h.param(0).and_then(|v| v.value().as_str()).unwrap_or("");
107        let inner = paths.inner.lock().unwrap();
108        let path = inner.get(param).map(String::as_str).unwrap_or(param);
109        out.write(path)?;
110        Ok(())
111    }
112}
rune/doc/templating.rs

rune/doc/
templating.rs
