Rework book example to support upload book photo.

webcc/response_builder.cc

@@ -43,6 +43,18 @@ ResponsePtr ResponseBuilder::operator()() {
   return response;
 }
 
+ResponseBuilder& ResponseBuilder::File(const webcc::Path& path,
+                                       bool infer_media_type,
+                                       std::size_t chunk_size) {
+  body_.reset(new FileBody{ path, chunk_size });
+
+  if (infer_media_type) {
+    media_type_ = media_types::FromExtension(path.extension().string());
+  }
+
+  return *this;
+}
+
 ResponseBuilder& ResponseBuilder::Date() {
   headers_.push_back(headers::kDate);
   headers_.push_back(utility::GetTimestamp());

webcc/response_builder.h

@@ -92,6 +92,11 @@ public:
     return *this;
   }
 
+  // Use the file content as body.
+  // NOTE: Error::kFileError might be thrown.
+  ResponseBuilder& File(const webcc::Path& path, bool infer_media_type = true,
+                        std::size_t chunk_size = 1024);
+
   ResponseBuilder& Header(const std::string& key, const std::string& value) {
     headers_.push_back(key);
     headers_.push_back(value);