add default_namespace attribute

issue #45

yaserde/tests/se_namespace.rs

@@ -161,6 +161,27 @@ fn ser_struct_default_namespace() {
   convert_and_validate!(model, content);
 }
 
+#[test]
+fn ser_struct_default_namespace_via_attribute() {
+  #[derive(YaSerialize, PartialEq, Debug)]
+  #[yaserde(
+    root = "tt",
+    default_namespace = "ttml",
+    namespace = "ttml: http://www.w3.org/ns/ttml",
+    namespace = "ttm: http://www.w3.org/ns/ttml#metadata"
+  )]
+  pub struct XmlStruct {
+    item: String,
+  }
+
+  let model = XmlStruct {
+    item: "something".to_string(),
+  };
+
+  let content = "<?xml version=\"1.0\" encoding=\"utf-8\"?><tt xmlns=\"http://www.w3.org/ns/ttml\" xmlns:ttm=\"http://www.w3.org/ns/ttml#metadata\"><item>something</item></tt>";
+  convert_and_validate!(model, content);
+}
+
 #[test]
 fn de_struct_namespace_nested() {
   #[derive(YaSerialize, Default, PartialEq, Debug)]

yaserde_derive/src/attribute.rs

@@ -6,14 +6,15 @@ use syn::Attribute;
 
 #[derive(Debug, PartialEq, Clone)]
 pub struct YaSerdeAttribute {
-  pub root: Option<String>,
-  pub rename: Option<String>,
-  pub prefix: Option<String>,
+  pub attribute: bool,
   pub default: Option<String>,
+  pub default_namespace: Option<String>,
+  pub flatten: bool,
   pub namespaces: BTreeMap<String, String>,
-  pub attribute: bool,
+  pub prefix: Option<String>,
+  pub root: Option<String>,
+  pub rename: Option<String>,
   pub text: bool,
-  pub flatten: bool,
 }
 
 fn get_value(iter: &mut IntoIter) -> Option<String> {
@@ -33,13 +34,14 @@ fn get_value(iter: &mut IntoIter) -> Option<String> {
 impl YaSerdeAttribute {
   pub fn parse(attrs: &[Attribute]) -> YaSerdeAttribute {
     let mut attribute = false;
+    let mut flatten = false;
+    let mut default = None;
+    let mut default_namespace = None;
     let mut namespaces = BTreeMap::new();
     let mut prefix = None;
     let mut rename = None;
     let mut root = None;
-    let mut default = None;
     let mut text = false;
-    let mut flatten = false;
 
     for attr in attrs.iter() {
       let mut attr_iter = attr.clone().tokens.into_iter();
@@ -54,6 +56,15 @@ impl YaSerdeAttribute {
                   "attribute" => {
                     attribute = true;
                   }
+                  "default" => {
+                    default = get_value(&mut attr_iter);
+                  }
+                  "default_namespace" => {
+                    default_namespace = get_value(&mut attr_iter);
+                  }
+                  "flatten" => {
+                    flatten = true;
+                  }
                   "namespace" => {
                     if let Some(namespace) = get_value(&mut attr_iter) {
                       let splitted: Vec<&str> = namespace.split(": ").collect();
@@ -74,15 +85,9 @@ impl YaSerdeAttribute {
                   "root" => {
                     root = get_value(&mut attr_iter);
                   }
-                  "default" => {
-                    default = get_value(&mut attr_iter);
-                  }
                   "text" => {
                     text = true;
                   }
-                  "flatten" => {
-                    flatten = true;
-                  }
                   _ => {}
                 }
               }
@@ -94,13 +99,14 @@ impl YaSerdeAttribute {
 
     YaSerdeAttribute {
       attribute,
+      default,
+      default_namespace,
+      flatten,
       namespaces,
       prefix,
       rename,
       root,
-      default,
       text,
-      flatten,
     }
   }
 }
@@ -112,14 +118,15 @@ fn parse_empty_attributes() {
 
   assert_eq!(
     YaSerdeAttribute {
-      root: None,
-      rename: None,
-      prefix: None,
+      attribute: false,
       default: None,
+      default_namespace: None,
+      flatten: false,
       namespaces: BTreeMap::new(),
-      attribute: false,
+      prefix: None,
+      root: None,
+      rename: None,
       text: false,
-      flatten: false,
     },
     attrs
   );
@@ -160,14 +167,15 @@ fn parse_attributes() {
 
   assert_eq!(
     YaSerdeAttribute {
-      root: None,
-      rename: None,
-      prefix: None,
+      attribute: true,
       default: None,
+      default_namespace: None,
+      flatten: false,
       namespaces: BTreeMap::new(),
-      attribute: true,
+      prefix: None,
+      root: None,
+      rename: None,
       text: false,
-      flatten: false,
     },
     attrs
   );

yaserde_derive/src/ser/expand_enum.rs

@@ -12,6 +12,7 @@ pub fn serialize(
   name: &Ident,
   root: &str,
   namespaces: &BTreeMap<String, String>,
+  default_namespace: &Option<String>,
 ) -> TokenStream {
   let write_enum_content: TokenStream = data_enum
     .variants
@@ -212,6 +213,13 @@ pub fn serialize(
   let add_namespaces: TokenStream = namespaces
     .iter()
     .map(|(prefix, namespace)| {
+      if let Some(dn) = default_namespace {
+        if dn == prefix {
+          return Some(quote!(
+            .default_ns(#namespace)
+          ));
+        }
+      }
       Some(quote!(
         .ns(#prefix, #namespace)
       ))

yaserde_derive/src/ser/expand_struct.rs

@@ -14,6 +14,7 @@ pub fn serialize(
   name: &Ident,
   root: &str,
   namespaces: &BTreeMap<String, String>,
+  default_namespace: &Option<String>,
 ) -> TokenStream {
   let build_attributes: TokenStream = data_struct
     .fields
@@ -208,6 +209,13 @@ pub fn serialize(
   let add_namespaces: TokenStream = namespaces
     .iter()
     .map(|(prefix, namespace)| {
+      if let Some(dn) = default_namespace {
+        if dn == prefix {
+          return Some(quote!(
+            .default_ns(#namespace)
+          ));
+        }
+      }
       Some(quote!(
         .ns(#prefix, #namespace)
       ))

yaserde_derive/src/ser/mod.rs

@@ -22,12 +22,20 @@ pub fn expand_derive_serialize(ast: &syn::DeriveInput) -> Result<TokenStream, St
   };
 
   let impl_block = match *data {
-    syn::Data::Struct(ref data_struct) => {
-      expand_struct::serialize(data_struct, name, &root, &root_attrs.namespaces)
-    }
-    syn::Data::Enum(ref data_enum) => {
-      expand_enum::serialize(data_enum, name, &root, &root_attrs.namespaces)
-    }
+    syn::Data::Struct(ref data_struct) => expand_struct::serialize(
+      data_struct,
+      name,
+      &root,
+      &root_attrs.namespaces,
+      &root_attrs.default_namespace,
+    ),
+    syn::Data::Enum(ref data_enum) => expand_enum::serialize(
+      data_enum,
+      name,
+      &root,
+      &root_attrs.namespaces,
+      &root_attrs.default_namespace,
+    ),
     syn::Data::Union(ref _data_union) => unimplemented!(),
   };