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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:47:55 +0000
commit2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4 (patch)
tree033cc839730fda84ff08db877037977be94e5e3a /crates/mdman/src/hbs.rs
parentInitial commit. (diff)
downloadcargo-2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4.tar.xz
cargo-2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4.zip
Adding upstream version 0.70.1+ds1.upstream/0.70.1+ds1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'crates/mdman/src/hbs.rs')
-rw-r--r--crates/mdman/src/hbs.rs215
1 files changed, 215 insertions, 0 deletions
diff --git a/crates/mdman/src/hbs.rs b/crates/mdman/src/hbs.rs
new file mode 100644
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+++ b/crates/mdman/src/hbs.rs
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+//! Handlebars template processing.
+
+use crate::format::Formatter;
+use anyhow::Error;
+use handlebars::{
+ handlebars_helper, Context, Decorator, Handlebars, Helper, HelperDef, HelperResult, Output,
+ RenderContext, RenderError, Renderable,
+};
+use std::collections::HashMap;
+use std::path::Path;
+
+type FormatterRef<'a> = &'a (dyn Formatter + Send + Sync);
+
+/// Processes the handlebars template at the given file.
+pub fn expand(file: &Path, formatter: FormatterRef) -> Result<String, Error> {
+ let mut handlebars = Handlebars::new();
+ handlebars.set_strict_mode(true);
+ handlebars.register_helper("lower", Box::new(lower));
+ handlebars.register_helper("options", Box::new(OptionsHelper { formatter }));
+ handlebars.register_helper("option", Box::new(OptionHelper { formatter }));
+ handlebars.register_helper("man", Box::new(ManLinkHelper { formatter }));
+ handlebars.register_decorator("set", Box::new(set_decorator));
+ handlebars.register_template_file("template", file)?;
+ let includes = file.parent().unwrap().join("includes");
+ handlebars.register_templates_directory(".md", includes)?;
+ let man_name = file
+ .file_stem()
+ .expect("expected filename")
+ .to_str()
+ .expect("utf8 filename")
+ .to_string();
+ let data = HashMap::from([("man_name", man_name)]);
+ let expanded = handlebars.render("template", &data)?;
+ Ok(expanded)
+}
+
+/// Helper for `{{#options}}` block.
+struct OptionsHelper<'a> {
+ formatter: FormatterRef<'a>,
+}
+
+impl HelperDef for OptionsHelper<'_> {
+ fn call<'reg: 'rc, 'rc>(
+ &self,
+ h: &Helper<'reg, 'rc>,
+ r: &'reg Handlebars<'reg>,
+ ctx: &'rc Context,
+ rc: &mut RenderContext<'reg, 'rc>,
+ out: &mut dyn Output,
+ ) -> HelperResult {
+ if in_options(rc) {
+ return Err(RenderError::new("options blocks cannot be nested"));
+ }
+ // Prevent nested {{#options}}.
+ set_in_context(rc, "__MDMAN_IN_OPTIONS", serde_json::Value::Bool(true));
+ let s = self.formatter.render_options_start();
+ out.write(&s)?;
+ let t = match h.template() {
+ Some(t) => t,
+ None => return Err(RenderError::new("options block must not be empty")),
+ };
+ let block = t.renders(r, ctx, rc)?;
+ out.write(&block)?;
+
+ let s = self.formatter.render_options_end();
+ out.write(&s)?;
+ remove_from_context(rc, "__MDMAN_IN_OPTIONS");
+ Ok(())
+ }
+}
+
+/// Whether or not the context is currently inside a `{{#options}}` block.
+fn in_options(rc: &RenderContext<'_, '_>) -> bool {
+ rc.context()
+ .map_or(false, |ctx| ctx.data().get("__MDMAN_IN_OPTIONS").is_some())
+}
+
+/// Helper for `{{#option}}` block.
+struct OptionHelper<'a> {
+ formatter: FormatterRef<'a>,
+}
+
+impl HelperDef for OptionHelper<'_> {
+ fn call<'reg: 'rc, 'rc>(
+ &self,
+ h: &Helper<'reg, 'rc>,
+ r: &'reg Handlebars<'reg>,
+ ctx: &'rc Context,
+ rc: &mut RenderContext<'reg, 'rc>,
+ out: &mut dyn Output,
+ ) -> HelperResult {
+ if !in_options(rc) {
+ return Err(RenderError::new("option must be in options block"));
+ }
+ let params = h.params();
+ if params.is_empty() {
+ return Err(RenderError::new(
+ "option block must have at least one param",
+ ));
+ }
+ // Convert params to strings.
+ let params = params
+ .iter()
+ .map(|param| {
+ param
+ .value()
+ .as_str()
+ .ok_or_else(|| RenderError::new("option params must be strings"))
+ })
+ .collect::<Result<Vec<&str>, RenderError>>()?;
+ let t = match h.template() {
+ Some(t) => t,
+ None => return Err(RenderError::new("option block must not be empty")),
+ };
+ // Render the block.
+ let block = t.renders(r, ctx, rc)?;
+
+ // Get the name of this page.
+ let man_name = ctx
+ .data()
+ .get("man_name")
+ .expect("expected man_name in context")
+ .as_str()
+ .expect("expect man_name str");
+
+ // Ask the formatter to convert this option to its format.
+ let option = self
+ .formatter
+ .render_option(&params, &block, man_name)
+ .map_err(|e| RenderError::new(format!("option render failed: {}", e)))?;
+ out.write(&option)?;
+ Ok(())
+ }
+}
+
+/// Helper for `{{man name section}}` expression.
+struct ManLinkHelper<'a> {
+ formatter: FormatterRef<'a>,
+}
+
+impl HelperDef for ManLinkHelper<'_> {
+ fn call<'reg: 'rc, 'rc>(
+ &self,
+ h: &Helper<'reg, 'rc>,
+ _r: &'reg Handlebars<'reg>,
+ _ctx: &'rc Context,
+ _rc: &mut RenderContext<'reg, 'rc>,
+ out: &mut dyn Output,
+ ) -> HelperResult {
+ let params = h.params();
+ if params.len() != 2 {
+ return Err(RenderError::new("{{man}} must have two arguments"));
+ }
+ let name = params[0]
+ .value()
+ .as_str()
+ .ok_or_else(|| RenderError::new("man link name must be a string"))?;
+ let section = params[1]
+ .value()
+ .as_u64()
+ .ok_or_else(|| RenderError::new("man link section must be an integer"))?;
+ let section =
+ u8::try_from(section).map_err(|_e| RenderError::new("section number too large"))?;
+ let link = self
+ .formatter
+ .linkify_man_to_md(name, section)
+ .map_err(|e| RenderError::new(format!("failed to linkify man: {}", e)))?;
+ out.write(&link)?;
+ Ok(())
+ }
+}
+
+/// `{{*set var=value}}` decorator.
+///
+/// This sets a variable to a value within the template context.
+fn set_decorator(
+ d: &Decorator,
+ _: &Handlebars,
+ _ctx: &Context,
+ rc: &mut RenderContext,
+) -> Result<(), RenderError> {
+ let data_to_set = d.hash();
+ for (k, v) in data_to_set {
+ set_in_context(rc, k, v.value().clone());
+ }
+ Ok(())
+}
+
+/// Sets a variable to a value within the context.
+fn set_in_context(rc: &mut RenderContext, key: &str, value: serde_json::Value) {
+ let mut ctx = match rc.context() {
+ Some(c) => (*c).clone(),
+ None => Context::wraps(serde_json::Value::Object(serde_json::Map::new())).unwrap(),
+ };
+ if let serde_json::Value::Object(m) = ctx.data_mut() {
+ m.insert(key.to_string(), value);
+ rc.set_context(ctx);
+ } else {
+ panic!("expected object in context");
+ }
+}
+
+/// Removes a variable from the context.
+fn remove_from_context(rc: &mut RenderContext, key: &str) {
+ let ctx = rc.context().expect("cannot remove from null context");
+ let mut ctx = (*ctx).clone();
+ if let serde_json::Value::Object(m) = ctx.data_mut() {
+ m.remove(key);
+ rc.set_context(ctx);
+ } else {
+ panic!("expected object in context");
+ }
+}
+
+handlebars_helper!(lower: |s: str| s.to_lowercase());