From 4c0388d11e1bafb85250b649ff610d3f9c7f9452 Mon Sep 17 00:00:00 2001
From: René Kijewski <kijewski@library.vetmed.fu-berlin.de>
Date: Thu, 10 Mar 2022 08:44:35 +0100
Subject: Reduce askama_derive to a single re-export
All the hard work in askama_derive was actually done in askama_shared.
This PR removes the back-and-forth interaction between the two crates.
Now askama_derive is a single re-export of `#[derive(Template)]` which
has to be done in a proc_macro crate.
This most likely means that askama_derive is "final", unless another
derive template needs to be introduced in the future.
---
askama_shared/src/derive.rs | 105 ++++++++++++++++++++++++++++++++++++++++++++
askama_shared/src/lib.rs | 2 +
2 files changed, 107 insertions(+)
create mode 100644 askama_shared/src/derive.rs
(limited to 'askama_shared/src')
diff --git a/askama_shared/src/derive.rs b/askama_shared/src/derive.rs
new file mode 100644
index 0000000..04b3ba0
--- /dev/null
+++ b/askama_shared/src/derive.rs
@@ -0,0 +1,105 @@
+use std::collections::HashMap;
+use std::path::PathBuf;
+
+use proc_macro2::TokenStream;
+
+use crate::heritage::{Context, Heritage};
+use crate::input::{Print, Source, TemplateInput};
+use crate::parser::{parse, Expr, Node};
+use crate::{generator, get_template_source, read_config_file, CompileError, Config};
+
+/// The actual implementation for askama_derive::Template
+pub fn derive_template(input: TokenStream) -> TokenStream {
+ let ast: syn::DeriveInput = syn::parse2(input).unwrap();
+ match build_template(&ast) {
+ Ok(source) => source.parse().unwrap(),
+ Err(e) => e.into_compile_error(),
+ }
+}
+
+/// Takes a `syn::DeriveInput` and generates source code for it
+///
+/// Reads the metadata from the `template()` attribute to get the template
+/// metadata, then fetches the source from the filesystem. The source is
+/// parsed, and the parse tree is fed to the code generator. Will print
+/// the parse tree and/or generated source according to the `print` key's
+/// value as passed to the `template()` attribute.
+fn build_template(ast: &syn::DeriveInput) -> Result<String, CompileError> {
+ let config_toml = read_config_file()?;
+ let config = Config::new(&config_toml)?;
+ let input = TemplateInput::new(ast, &config)?;
+ let source: String = match input.source {
+ Source::Source(ref s) => s.clone(),
+ Source::Path(_) => get_template_source(&input.path)?,
+ };
+
+ let mut sources = HashMap::new();
+ find_used_templates(&input, &mut sources, source)?;
+
+ let mut parsed = HashMap::new();
+ for (path, src) in &sources {
+ parsed.insert(path.as_path(), parse(src, input.syntax)?);
+ }
+
+ let mut contexts = HashMap::new();
+ for (path, nodes) in &parsed {
+ contexts.insert(*path, Context::new(input.config, path, nodes)?);
+ }
+
+ let ctx = &contexts[input.path.as_path()];
+ let heritage = if !ctx.blocks.is_empty() || ctx.extends.is_some() {
+ Some(Heritage::new(ctx, &contexts))
+ } else {
+ None
+ };
+
+ if input.print == Print::Ast || input.print == Print::All {
+ eprintln!("{:?}", parsed[input.path.as_path()]);
+ }
+
+ let code = generator::generate(&input, &contexts, heritage.as_ref())?;
+ if input.print == Print::Code || input.print == Print::All {
+ eprintln!("{}", code);
+ }
+ Ok(code)
+}
+
+fn find_used_templates(
+ input: &TemplateInput<'_>,
+ map: &mut HashMap<PathBuf, String>,
+ source: String,
+) -> Result<(), CompileError> {
+ let mut dependency_graph = Vec::new();
+ let mut check = vec![(input.path.clone(), source)];
+ while let Some((path, source)) = check.pop() {
+ for n in parse(&source, input.syntax)? {
+ match n {
+ Node::Extends(Expr::StrLit(extends)) => {
+ let extends = input.config.find_template(extends, Some(&path))?;
+ let dependency_path = (path.clone(), extends.clone());
+ if dependency_graph.contains(&dependency_path) {
+ return Err(format!(
+ "cyclic dependecy in graph {:#?}",
+ dependency_graph
+ .iter()
+ .map(|e| format!("{:#?} --> {:#?}", e.0, e.1))
+ .collect::<Vec<String>>()
+ )
+ .into());
+ }
+ dependency_graph.push(dependency_path);
+ let source = get_template_source(&extends)?;
+ check.push((extends, source));
+ }
+ Node::Import(_, import, _) => {
+ let import = input.config.find_template(import, Some(&path))?;
+ let source = get_template_source(&import)?;
+ check.push((import, source));
+ }
+ _ => {}
+ }
+ }
+ map.insert(path, source);
+ }
+ Ok(())
+}
diff --git a/askama_shared/src/lib.rs b/askama_shared/src/lib.rs
index 8a336bb..5a8facd 100644
--- a/askama_shared/src/lib.rs
+++ b/askama_shared/src/lib.rs
@@ -13,9 +13,11 @@ use proc_macro2::{Span, TokenStream};
#[cfg(feature = "serde")]
use serde::Deserialize;
+pub use crate::derive::derive_template;
pub use crate::input::extension_to_mime_type;
pub use askama_escape::MarkupDisplay;
+mod derive;
mod error;
pub use crate::error::{Error, Result};
pub mod filters;
--
cgit