Add Task trait for getting UUID from task

lib/domain/libimagtodo/src/error.rs

@@ -23,7 +23,10 @@ generate_error_module!(
         StoreError          => "Store Error",
         StoreIdError        => "Store Id handling error",
         ImportError         => "Error importing",
-        UTF8Error           => "Encountered non-UTF8 characters while reading input"
+        UTF8Error           => "Encountered non-UTF8 characters while reading input",
+        HeaderFieldMissing  => "Header field missing",
+        HeaderTypeError     => "Header field type error",
+        UuidParserError     => "Uuid parser error"
     );
 );
 

lib/domain/libimagtodo/src/lib.rs

@@ -47,5 +47,6 @@ module_entry_path_mod!("todo");
 
 pub mod error;
 pub mod result;
+pub mod task;
 pub mod taskstore;
 

lib/domain/libimagtodo/src/task.rs

@@ -0,0 +1,47 @@
+//
+// imag - the personal information management suite for the commandline
+// Copyright (C) 2015, 2016 Matthias Beyer <mail@beyermatthias.de> and contributors
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; version
+// 2.1 of the License.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+//
+
+use error::TodoErrorKind as TEK;
+use error::MapErrInto;
+use result::Result;
+
+use libimagstore::store::Entry;
+use libimagerror::into::IntoError;
+
+use uuid::Uuid;
+use toml::Value;
+use toml_query::read::TomlValueReadExt;
+
+pub trait Task {
+    fn get_uuid(&self) -> Result<Uuid>;
+}
+
+impl Task for Entry {
+    fn get_uuid(&self) -> Result<Uuid> {
+        match self.get_header().read("todo.uuid") {
+            Ok(Some(&Value::String(ref uuid))) => {
+                Uuid::parse_str(uuid).map_err_into(TEK::UuidParserError)
+            },
+            Ok(Some(_)) => Err(TEK::HeaderTypeError.into_error()),
+            Ok(None)    => Err(TEK::HeaderFieldMissing.into_error()),
+            Err(e)      => Err(e).map_err_into(TEK::StoreError),
+        }
+    }
+}
+