feat(doit): multi-part mime-type and add_parts()

Next we will implement the actual Read method

src/mako/lib/mbuild.mako

@@ -461,6 +461,7 @@ match result {
         ## "the trait `core::marker::Sized` is not implemented for the type `std::io::Read`"
         use hyper::client::IntoBody;
         use std::io::{Read, Seek};
+        use hyper::header::{ContentType, ContentLength};
         let mut params: Vec<(&str, String)> = Vec::with_capacity(${len(params) + len(reserved_params)} + ${paddfields}.len());
         % if response_schema:
         params.push(("alt", "json".to_string()));
@@ -614,14 +615,14 @@ else {
             % if request_value and simple_media_param:
             let mut request_value_reader = io::Cursor::new(json_encoded_request.clone().into_bytes());
             let mut mp_reader: cmn::MultiPartReader = Default::default();
-            let mut content_type = hyper::header::ContentType(json_mime_type.clone());
+            let mut content_type = ContentType(json_mime_type.clone());
             let mut body_reader: &mut io::Read = match ${simple_media_param.type.arg_name}.as_mut() {
                 Some(&mut (ref mut reader, size, ref mime)) => {
                     let rsize = request_value_reader.seek(io::SeekFrom::End(0)).unwrap();
                     request_value_reader.seek(io::SeekFrom::Start(0)).ok();
                     mp_reader = mp_reader.add_part(&mut request_value_reader, rsize, &json_mime_type)
                                          .add_part(reader, size, mime);
-                    ## TODO: content_type = multi-part
+                    content_type = ContentType(mp_reader.mime_type());
                     &mut mp_reader
                 }
                 None => &mut request_value_reader,
@@ -637,8 +638,8 @@ else {
                 % if request_value:
                 % if not simple_media_param:
 
-                .header(hyper::header::ContentType(json_mime_type.clone()))
-                .header(hyper::header::ContentLength(json_encoded_request.len() as u64))
+                .header(ContentType(json_mime_type.clone()))
+                .header(ContentLength(json_encoded_request.len() as u64))
                 .body(json_encoded_request.as_slice())\
                 % else:
 
@@ -649,8 +650,8 @@ else {
 ;
             % if simple_media_param and not request_value:
             if let Some(&mut (ref mut reader, size, ref mime)) = ${simple_media_param.type.arg_name}.as_mut() {
-                req = req.header(hyper::header::ContentType(mime.clone()))
-                         .header(hyper::header::ContentLength(size))
+                req = req.header(ContentType(mime.clone()))
+                         .header(ContentLength(size))
                          .body(reader.into_body());
             }
             % endif ## media upload handling

src/rust/cmn.rs

@@ -1,9 +1,10 @@
 use std::marker::MarkerTrait;
 use std::io::{self, Read, Seek, Cursor};
 
-use mime;
+use mime::{Mime, TopLevel, SubLevel, Attr, Value};
 use oauth2;
 use hyper;
+use hyper::header::{ContentType, ContentLength, Headers};
 
 /// Identifies the Hub. There is only one per library, this trait is supposed
 /// to make intended use more explicit.
@@ -117,6 +118,7 @@ pub enum Result<T = ()> {
     Success(T),
 }
 
+const BOUNDARY: &'static str = "MDuXWGyeE33QFXGchb2VFWc4Z7945d";
 
 /// Provides a `Read` interface that converts multiple parts into the protocol
 /// identified by [RFC2387](https://tools.ietf.org/html/rfc2387).
@@ -124,7 +126,7 @@ pub enum Result<T = ()> {
 /// to google APIs, and might not be a fully-featured implementation.
 #[derive(Default)]
 pub struct MultiPartReader<'a> {
-    raw_parts: Vec<(hyper::header::Headers, &'a mut Read)>,
+    raw_parts: Vec<(Headers, &'a mut Read)>,
     current_part: Option<(Cursor<Vec<u8>>, &'a mut Read)>,
 }
 
@@ -143,11 +145,23 @@ impl<'a> MultiPartReader<'a> {
     /// # Panics
     ///
     /// If this method is called after the first `read` call, it will panic
-    pub fn add_part(mut self, reader: &'a mut Read, size: u64, mime_type: &mime::Mime) -> MultiPartReader<'a> {
-        // let mut headers = hyper::header::Headers::
-        // raw_parts.push((headers, reader));
+    pub fn add_part(mut self, reader: &'a mut Read, size: u64, mime_type: &Mime) -> MultiPartReader<'a> {
+        let mut headers = Headers::new();
+        headers.set(ContentType(mime_type.clone()));
+        headers.set(ContentLength(size));
+        self.raw_parts.push((headers, reader));
         self
     }
+
+    /// Returns the mime-type representing our multi-part message.
+    /// Use it with the ContentType header.
+    pub fn mime_type(&self) -> Mime {
+        Mime(
+            TopLevel::Multipart,
+            SubLevel::Ext("Related".to_string()),
+            vec![(Attr::Ext("boundary".to_string()), Value::Ext(BOUNDARY.to_string()))],
+        )
+    }
 }
 
 impl<'a> Read for MultiPartReader<'a> {