From 2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 14:47:55 +0200 Subject: Adding upstream version 0.70.1+ds1. Signed-off-by: Daniel Baumann --- crates/mdman/src/hbs.rs | 215 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 215 insertions(+) create mode 100644 crates/mdman/src/hbs.rs (limited to 'crates/mdman/src/hbs.rs') diff --git a/crates/mdman/src/hbs.rs b/crates/mdman/src/hbs.rs new file mode 100644 index 0000000..81ad7ee --- /dev/null +++ b/crates/mdman/src/hbs.rs @@ -0,0 +1,215 @@ +//! 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 { + 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::, 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(¶ms, &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()); -- cgit v1.2.3