feat(handlebars) added initial handlebars bindings

4 files changed, 101 insertions, 7 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 624f1dd..18ef13f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@ repository = "https://github.com/1aim/mail-template"
 
 [features]
 default = []
-handlebars-bindings = []
+handlebars-bindings = ["handlebars"]
 
 [dependencies]
 mail-core = { git="https://github.com/1aim/mail", features=["serde-impl"] }
@@ -27,6 +27,7 @@ serde = { version="1", features=["derive"] }
 toml = "0.4.8"
 maybe-owned = "0.3.2"
 
+handlebars = { version="1.1.0", optional=true }
 
 [dependencies.mime]
 git="https://github.com/1aim/mime"
diff --git a/examples/readme.rs b/examples/readme.rs
deleted file mode 100644
index ea19f16..0000000
--- a/examples/readme.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-
-
-
-fn main() {
-
-}
\ No newline at end of file
diff --git a/src/handlebars.rs b/src/handlebars.rs
new file mode 100644
index 0000000..887dce1
--- /dev/null
+++ b/src/handlebars.rs
@@ -0,0 +1,96 @@
+use hbs;
+use serde::{Serialize, Deserialize};
+use galemu::{Bound, BoundExt, create_gal_wrapper_type, Ref};
+use failure::Error;
+
+
+use super::{
+    TemplateEngine,
+    TemplateEngineCanHandleData,
+    BodyTemplate,
+    PreparationData,
+    AdditionalCIds,
+    PathRebaseable,
+    UnsupportedPathError,
+    serde_impl
+};
+
+
+
+pub struct Handlebars {
+    inner: hbs::Handlebars,
+    name_counter: usize
+}
+
+impl Handlebars {
+
+    fn next_body_template_name(&mut self) -> String {
+        let name = format!("body_{}", self.name_counter);
+        self.name_counter += 1;
+        name
+    }
+}
+impl TemplateEngine for Handlebars {
+    type Id = String;
+
+    type LazyBodyTemplate = serde_impl::StandardLazyBodyTemplate;
+
+    fn load_body_template(&mut self, tmpl: Self::LazyBodyTemplate)
+        -> Result<BodyTemplate<Self>, Error>
+    {
+        let StandardLazyBodyTemplate {
+            path, embeddings, media_type
+        } = tmpl;
+
+        let name = self.next_body_template_name();
+        self.inner.register_template_file(name, path)?;
+
+        let media_type =
+            if let Some(media_type) = media_type {
+                media_type
+            } else if let Some(extension) = path.extension().and_then(|osstr| osstr.as_str()) {
+                match extension {
+                    "html" => "text/html; charset=utf-8".parse().unwrap(),
+                    "txt" => "text/plain; charset=utf-8".parse().unwrap()
+                }
+            } else {
+                return Err(failure::err_msg(
+                    "handlebars requires html/txt file extension or media type given in template spec"
+                ));
+            };
+
+        Ok(BodyTemplate {
+            template_id: name,
+            media_type: TODO,
+            inline_embeddings: Default::default(),
+        })
+    }
+
+    fn load_subject_template(&mut self, template_string: String)
+        -> Result<Self::Id, Error>
+    {
+        Ok(self.inner.register_template_string("subject".to_owned(), template_string)?)
+    }
+}
+
+/// Additional trait a template engine needs to implement for the types it can process as input.
+///
+/// This could for example be implemented in a wild card impl for the template engine for
+/// any data `D` which implements `Serialize`.
+impl<D> TemplateEngineCanHandleData<D> for Handlebars
+    where D: Serialize
+{
+    fn render<'r, 'a>(
+        &'r self,
+        id: &'r Self::Id,
+        data: &'r D,
+        additional_cids: AdditionalCIds<'r>
+    ) -> Result<String, Error> {
+        Ok(self.inner.render(id, SerHelper { data, cids: additional_cid })?)
+    }
+}
+
+struct SerHelper<'r, D> {
+    data: &'r D,
+    cids: AdditionalCIds<'r>
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index dc9f529..b889213 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,6 +9,9 @@ extern crate maybe_owned;
 #[cfg(feature="handlebars")]
 extern crate handlebars as hbs;
 
+#[cfg(all(feature="handlebars", not(feature="handlebars-bindings")))]
+compile_error!("use feature `handlebars-bindings` instead of opt-dep-auto-feature `handlebars`");
+
 use std::{
     fs,
     collections::HashMap,