Merge pull request #36 from yuma140902/template-engine

add `TemplateEngine`

src/generator/handlebars_generator.rs

@@ -1,78 +1,21 @@
-use std::{
-    borrow::Borrow,
-    fs,
-    path::{Path, PathBuf},
-};
+use std::{borrow::Borrow, fs, path::Path};
 
 use anyhow::Context as _;
-use handlebars::{
-    handlebars_helper, Context, Handlebars, Helper, HelperResult, JsonRender, Output,
-    RenderContext, RenderError,
-};
+use handlebars::Handlebars;
 use path_absolutize::Absolutize;
 use serde_json::{Map, Value as Json};
 use serde_yaml::Value as Yaml;
 use tracing::info;
 use walkdir::WalkDir;
 
-use crate::{directory, project_config::GeneratorRule};
+use crate::{directory, handlebars_helpers, project_config::GeneratorRule};
 
 use super::{Generator, GeneratorResult};
 
-handlebars_helper!(md2html: |markdown: String| {
-    let options = pulldown_cmark::Options::empty();
-    let parser = pulldown_cmark::Parser::new_ext(&markdown, options);
-    let mut html_output = String::new();
-    pulldown_cmark::html::push_html(&mut html_output, parser);
-    html_output
-});
-
-fn resolve(
-    h: &Helper<'_, '_>,
-    _: &Handlebars<'_>,
-    ctx: &Context,
-    _rc: &mut RenderContext<'_, '_>,
-    out: &mut dyn Output,
-) -> HelperResult {
-    let target_input_path = PathBuf::from(
-        h.param(0)
-            .and_then(|v| v.value().as_str())
-            .ok_or_else(|| RenderError::new("target_input_path not specified"))?,
-    );
-    let project_root = PathBuf::from(
-        ctx.data()
-            .get("project_root")
-            .ok_or_else(|| RenderError::new("project_root not specified"))?
-            .render()
-            .as_str(),
-    );
-    let output_directory = directory::get_output_directory(project_root);
-    let self_output_filepath = PathBuf::from(
-        ctx.data()
-            .get("output_file")
-            .ok_or_else(|| RenderError::new("output_file not specified"))?
-            .render()
-            .as_str(),
-    );
-    let self_output_parent = self_output_filepath.parent().ok_or_else(|| {
-        RenderError::new(format!(
-            "could not get parent directory for output_file '{}'",
-            self_output_filepath.display()
-        ))
-    })?;
-
-    let target_output_path = output_directory.join(target_input_path); //TODO:
-                                                                       //rule.export_extension
-                                                                       //rule.export_base
-    let relative_path = directory::get_relative_path(target_output_path, self_output_parent);
-    write!(out, "{}", relative_path.display())?;
-    Ok(())
-}
-
 fn setup_handlebars(project_root: impl AsRef<Path>) -> Handlebars<'static> {
     let mut handlebars = Handlebars::new();
-    handlebars.register_helper("md2html", Box::new(md2html));
-    handlebars.register_helper("resolve", Box::new(resolve));
+    handlebars.register_helper("md2html", Box::new(handlebars_helpers::md2html));
+    handlebars.register_helper("resolve", Box::new(handlebars_helpers::resolve));
 
     // enumerate template files
     for path in WalkDir::new(directory::get_templates_directory(project_root))

src/handlebars_helpers.rs

@@ -0,0 +1,62 @@
+//! This module defines a custom Helper for Tempura.
+//! Helper is a term used in Handlebars to refer to a kind of function that can be called from a template.
+
+use std::path::PathBuf;
+
+use handlebars::{
+    handlebars_helper, Context, Handlebars, Helper, HelperResult, JsonRender, Output,
+    RenderContext, RenderError,
+};
+
+use crate::directory;
+
+handlebars_helper!(md2html: |markdown: String| {
+    let options = pulldown_cmark::Options::empty();
+    let parser = pulldown_cmark::Parser::new_ext(&markdown, options);
+    let mut html_output = String::new();
+    pulldown_cmark::html::push_html(&mut html_output, parser);
+    html_output
+});
+
+// TODO:
+pub fn resolve(
+    h: &Helper<'_, '_>,
+    _: &Handlebars<'_>,
+    ctx: &Context,
+    _rc: &mut RenderContext<'_, '_>,
+    out: &mut dyn Output,
+) -> HelperResult {
+    let target_input_path = PathBuf::from(
+        h.param(0)
+            .and_then(|v| v.value().as_str())
+            .ok_or_else(|| RenderError::new("target_input_path not specified"))?,
+    );
+    let project_root = PathBuf::from(
+        ctx.data()
+            .get("project_root")
+            .ok_or_else(|| RenderError::new("project_root not specified"))?
+            .render()
+            .as_str(),
+    );
+    let output_directory = directory::get_output_directory(project_root);
+    let self_output_filepath = PathBuf::from(
+        ctx.data()
+            .get("output_file")
+            .ok_or_else(|| RenderError::new("output_file not specified"))?
+            .render()
+            .as_str(),
+    );
+    let self_output_parent = self_output_filepath.parent().ok_or_else(|| {
+        RenderError::new(format!(
+            "could not get parent directory for output_file '{}'",
+            self_output_filepath.display()
+        ))
+    })?;
+
+    let target_output_path = output_directory.join(target_input_path); //TODO:
+                                                                       //rule.export_extension
+                                                                       //rule.export_base
+    let relative_path = directory::get_relative_path(target_output_path, self_output_parent);
+    write!(out, "{}", relative_path.display())?;
+    Ok(())
+}

src/lib.rs

@@ -15,11 +15,14 @@ use crate::project_config::ProjectConfig;
 pub mod cli;
 pub mod directory;
 pub mod generator;
+pub mod handlebars_helpers;
 mod loader;
 pub mod project_config;
+mod template_engine;
 mod value;
 
 pub use loader::*;
+pub use template_engine::*;
 pub use value::*;
 
 fn build_single_file(

src/template_engine.rs

@@ -0,0 +1,23 @@
+use handlebars::Handlebars;
+
+use crate::handlebars_helpers;
+
+/// TemplateEngine is a wrapper for Handlebars and processes templates and [`Value`](crate::Value)s.
+pub struct TemplateEngine(Handlebars<'static>);
+
+impl TemplateEngine {
+    pub fn new() -> Self {
+        let mut handlebars = Handlebars::new();
+
+        handlebars.register_helper("md2html", Box::new(handlebars_helpers::md2html));
+        handlebars.register_helper("resolve", Box::new(handlebars_helpers::resolve));
+
+        Self(handlebars)
+    }
+}
+
+impl Default for TemplateEngine {
+    fn default() -> Self {
+        Self::new()
+    }
+}