Fields mandatory unless specified otherwise

examples/src/boscop.rs

@@ -61,24 +61,24 @@ pub struct Control {
   pub h: u32,
   #[yaserde(attribute)]
   pub color: String,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub scalef: f32,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub scalet: f32,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub local_off: bool,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub sp: bool,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub sr: bool,
   pub midi: Vec<Midi>,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub response: String,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub inverted: String,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub centered: String,
-  #[yaserde(attribute)]
+  #[yaserde(attribute, default)]
   pub norollover: String,
 }
 

yaserde/tests/flatten.rs

@@ -251,6 +251,7 @@ fn flatten_name_in_unknown_child() {
   }
 
   #[derive(PartialEq, Debug, YaDeserialize, YaSerialize)]
+  #[yaserde(default)]
   enum Value {
     Foo(FooStruct),
   }

yaserde/tests/namespace.rs

@@ -330,7 +330,8 @@ fn enum_namespace() {
   #[yaserde(
     rename = "root",
     prefix = "ns",
-    namespace = "ns: http://www.sample.com/ns/domain"
+    namespace = "ns: http://www.sample.com/ns/domain",
+    default
   )]
   pub enum XmlStruct {
     #[yaserde(prefix = "ns")]
@@ -362,7 +363,8 @@ fn enum_multi_namespaces() {
   #[yaserde(
     rename = "root",
     namespace = "ns1: http://www.sample.com/ns/domain1",
-    namespace = "ns2: http://www.sample.com/ns/domain2"
+    namespace = "ns2: http://www.sample.com/ns/domain2",
+    default
   )]
   pub enum XmlStruct {
     #[yaserde(prefix = "ns1")]
@@ -405,7 +407,8 @@ fn enum_attribute_namespace() {
   #[yaserde(
     rename = "rootA",
     prefix = "ns",
-    namespace = "ns: http://www.sample.com/ns/domain"
+    namespace = "ns: http://www.sample.com/ns/domain",
+    default
   )]
   pub enum XmlStruct {
     #[yaserde(prefix = "ns")]

yaserde_derive/src/common/attribute.rs

@@ -31,6 +31,18 @@ fn get_value(iter: &mut IntoIter) -> Option<String> {
   }
 }
 
+fn get_value_or_default(iter: &mut IntoIter) -> Option<String> {
+  match (iter.next(), iter.next()) {
+    (Some(TokenTree::Punct(operator)), Some(TokenTree::Literal(value))) => if operator.as_char() == '=' {
+      Some(value.to_string().replace('"', ""))
+    } else {
+      None
+    },
+    (None, None) => Some(String::new()),
+    _ => None
+  }
+}
+
 impl YaSerdeAttribute {
   pub fn parse(attrs: &[Attribute]) -> YaSerdeAttribute {
     let mut attribute = false;
@@ -57,7 +69,7 @@ impl YaSerdeAttribute {
                   attribute = true;
                 }
                 "default" => {
-                  default = get_value(&mut attr_iter);
+                  default = get_value_or_default(&mut attr_iter);
                 }
                 "default_namespace" => {
                   default_namespace = get_value(&mut attr_iter);

yaserde_derive/src/common/field.rs

@@ -108,12 +108,16 @@ impl YaSerdeField {
     self.syn_field.span()
   }
 
-  pub fn get_default_function(&self) -> Option<Ident> {
-    self
-      .attributes
-      .default
-      .as_ref()
-      .map(|default| Ident::new(default, self.get_span()))
+  pub fn get_default_function(&self) -> Option<TokenStream> {
+    self.attributes.default.as_ref().map(|default| {
+      if default != "" {
+        let f = Ident::new(default, self.get_span());
+        quote!( #f )
+      } else {
+        let field_type = &self.syn_field.ty;
+        quote!(<#field_type as std::default::Default>::default)
+      }
+    })
   }
 
   pub fn get_skip_serializing_if_function(&self) -> Option<Ident> {

yaserde_derive/src/de/build_default_value.rs

@@ -2,6 +2,24 @@ use crate::common::YaSerdeField;
 use proc_macro2::TokenStream;
 use quote::quote;
 
+pub fn build_value(field: &YaSerdeField, field_type: Option<TokenStream>) -> Option<TokenStream> {
+  let label = field.get_value_label();
+
+  let value = field
+    .get_default_function()
+    .map(|default_function| quote!(::std::option::Option::Some(#default_function())))
+    .unwrap_or_else(|| quote!(::std::option::Option::None));
+
+  let field_type = field_type
+    .map(|field_type| quote!(: std::option::Option<#field_type>))
+    .unwrap_or_default();
+
+  Some(quote! {
+    #[allow(unused_mut)]
+    let mut #label #field_type = #value;
+  })
+}
+
 pub fn build_default_value(
   field: &YaSerdeField,
   field_type: Option<TokenStream>,
@@ -12,7 +30,7 @@ pub fn build_default_value(
   let default_value = field
     .get_default_function()
     .map(|default_function| quote!(#default_function()))
-    .unwrap_or_else(|| quote!(#value));
+    .unwrap_or_else(|| value);
 
   let field_type = field_type
     .map(|field_type| quote!(: #field_type))

yaserde_derive/src/de/expand_enum.rs

@@ -24,6 +24,18 @@ pub fn parse(
 
   let flatten = root_attributes.flatten;
 
+  let variant_not_detected = if let Some(default_function) = &root_attributes.default {
+    if default_function == "" {
+      quote!(::std::result::Result::Ok(<#name as ::std::default::Default>::default()))
+    } else {
+      quote!(#default_function())
+    }
+  } else {
+    quote!(::std::result::Result::Err(
+      "Failed to match variant in '".to_string() + stringify!(#name) + "'"
+    ))
+  };
+
   quote! {
     impl ::yaserde::YaDeserialize for #name {
       #[allow(unused_variables)]
@@ -91,9 +103,7 @@ pub fn parse(
         ::yaserde::__derive_debug!("Enum {} @ {}: success", stringify!(#name), start_depth);
         match enum_value {
           ::std::option::Option::Some(value) => ::std::result::Result::Ok(value),
-          ::std::option::Option::None => {
-            ::std::result::Result::Ok(<#name as ::std::default::Default>::default())
-          },
+          ::std::option::Option::None => #variant_not_detected,
         }
       }
     }

yaserde_derive/src/de/expand_struct.rs

@@ -1,5 +1,5 @@
 use crate::common::{Field, YaSerdeAttribute, YaSerdeField};
-use crate::de::build_default_value::build_default_value;
+use crate::de::build_default_value::{build_default_value, build_value};
 use heck::ToUpperCamelCase;
 use proc_macro2::{Span, TokenStream};
 use quote::quote;
@@ -23,11 +23,7 @@ pub fn parse(
     .iter()
     .map(|field| YaSerdeField::new(field.clone()))
     .filter_map(|field| match field.get_type() {
-      Field::FieldStruct { struct_name } => build_default_value(
-        &field,
-        Some(quote!(#struct_name)),
-        quote!(<#struct_name as ::std::default::Default>::default()),
-      ),
+      Field::FieldStruct { struct_name } => build_value(&field, Some(quote!(#struct_name))),
       Field::FieldOption { .. } => {
         build_default_value(&field, None, quote!(::std::option::Option::None))
       }
@@ -50,11 +46,17 @@ pub fn parse(
           )
         }
       },
+      string_type @ Field::FieldString if field.is_text_content() => {
+        let type_token: TokenStream = string_type.into();
+        build_default_value(
+          &field,
+          Some(type_token),
+          quote!(::std::string::String::new()),
+        )
+      }
       simple_type => {
         let type_token: TokenStream = simple_type.into();
-        let value_builder = quote!(<#type_token as ::std::default::Default>::default());
-
-        build_default_value(&field, Some(type_token), value_builder)
+        build_value(&field, Some(type_token))
       }
     })
     .collect();
@@ -184,12 +186,17 @@ pub fn parse(
       };
 
       match field.get_type() {
-        Field::FieldStruct { struct_name } => visit_struct(struct_name, quote! { = value }),
+        Field::FieldStruct { struct_name } => {
+          visit_struct(struct_name, quote! { = ::std::option::Option::Some(value) })
+        }
         Field::FieldOption { data_type } => {
           visit_sub(data_type, quote! { = ::std::option::Option::Some(value) })
         }
         Field::FieldVec { data_type } => visit_sub(data_type, quote! { .push(value) }),
-        simple_type => visit_simple(simple_type, quote! { = value }),
+        string_type @ Field::FieldString if field.is_text_content() => {
+          visit_simple(string_type, quote! { = value })
+        }
+        simple_type => visit_simple(simple_type, quote! { = ::std::option::Option::Some(value) }),
       }
     })
     .collect();
@@ -204,7 +211,7 @@ pub fn parse(
 
       match field.get_type() {
         Field::FieldStruct { .. } => Some(quote! {
-          #value_label = ::yaserde::de::from_str(&unused_xml_elements)?;
+          #value_label = Some(::yaserde::de::from_str(&unused_xml_elements)?);
         }),
         Field::FieldOption { data_type } => match *data_type {
           Field::FieldStruct { .. } => Some(quote! {
@@ -243,7 +250,7 @@ pub fn parse(
         Some(quote! {
           for attr in attributes {
             if attr.name.local_name == #label_name {
-              #label = attr.value.to_owned();
+              #label = Some(attr.value.to_owned());
             }
           }
         })
@@ -277,8 +284,10 @@ pub fn parse(
           visit_sub(data_type, quote! { = ::std::option::Option::Some(value) })
         }
         Field::FieldVec { .. } => unimplemented!(),
-        Field::FieldStruct { struct_name } => visit_struct(struct_name, quote! { = value }),
-        simple_type => visit_simple(simple_type, quote! { = value }),
+        Field::FieldStruct { struct_name } => {
+          visit_struct(struct_name, quote! { = ::std::option::Option::Some(value) })
+        }
+        simple_type => visit_simple(simple_type, quote! { = ::std::option::Option::Some(value) }),
       }
     })
     .collect();
@@ -309,7 +318,7 @@ pub fn parse(
         Field::FieldStruct { .. } | Field::FieldVec { .. } => None,
         simple_type => {
           let type_token = TokenStream::from(simple_type);
-          set_text(&quote! { #type_token::from_str(text_content).unwrap() })
+          set_text(&quote! { Some(#type_token::from_str(text_content).unwrap()) })
         }
       }
     })
@@ -323,7 +332,12 @@ pub fn parse(
       let label = &field.label();
       let value_label = field.get_value_label();
 
-      quote! { #label: #value_label, }
+      match field.get_type() {
+        Field::FieldVec {..} => quote! { #label: #value_label, },
+        Field::FieldOption {..} => quote! { #label: #value_label, },
+        Field::FieldString if field.is_text_content() => quote! { #label: #value_label, },
+        _ => quote! { #label: #value_label.ok_or_else(|| "Missing field '".to_string() + stringify!(#label) + "'")?, }
+      }
     })
     .collect();
 

yaserde_derive/src/ser/expand_struct.rs

@@ -152,7 +152,8 @@ pub fn serialize(
             writer.write(data_event).map_err(|e| e.to_string())?;
           )),
           _ => Some(quote!(
-            let data_event = ::yaserde::__xml::writer::XmlEvent::characters(&self.#label);
+            let s = self.#label.to_string();
+            let data_event = ::yaserde::__xml::writer::XmlEvent::characters(&s);
             writer.write(data_event).map_err(|e| e.to_string())?;
           )),
         };