Study: Save study metadata in SQL.

src/Model/Study.py

@@ -83,6 +83,7 @@ class Study(SQLModel):
     def filename(self, filename):
         self._filename = str(filename)
         self._init_db_file(filename, is_new = True)
+        self.status.modified()
 
     @property
     def time_system(self):
@@ -136,6 +137,22 @@ class Study(SQLModel):
             f"INSERT INTO info VALUES ('version', '{self._sql_format(self._version)}')",
             commit = True
         )
+        self.execute("INSERT INTO info VALUES ('name', '')")
+        self.execute("INSERT INTO info VALUES ('description', '')")
+        self.execute(f"INSERT INTO info VALUES ('time_system', '{self._time_system}')")
+        self.execute(
+            f"INSERT INTO info VALUES ('date', " +
+            "'{self._date.timestamp()}')"
+        )
+
+        self.execute(
+            f"INSERT INTO info VALUES ('creation_date', " +
+            "'{self.creation_time.timestamp()}')"
+        )
+        self.execute(
+            f"INSERT INTO info VALUES ('last_save_date', " +
+            "'{self.last_save_time.timestamp()}')"
+        )
 
         self._create_submodel()
         self.commit()
@@ -159,7 +176,19 @@ class Study(SQLModel):
         new = cls(init_new = False, filename = filename)
 
         # TODO: Load metadata
-        print("TODO: Load metadata")
+        new.name = new.execute("SELECT value FROM info WHERE key='name'")[0]
+        new.description = new.execute("SELECT value FROM info WHERE key='description'")[0]
+        new._time_system = new.execute("SELECT value FROM info WHERE key='time_system'")[0]
+        new._date = datetime.fromtimestamp(
+            float(new.execute("SELECT value FROM info WHERE key='date'")[0])
+        )
+
+        new.creation_date = datetime.fromtimestamp(
+            float(new.execute("SELECT value FROM info WHERE key='creation_date'")[0])
+        )
+        new.last_save_date = datetime.fromtimestamp(
+            float(new.execute("SELECT value FROM info WHERE key='last_save_date'")[0])
+        )
 
         # Load river data
         new._river = River._sql_load(
@@ -174,5 +203,12 @@ class Study(SQLModel):
         return new
 
     def _save(self):
+        self.execute(f"UPDATE info SET value='{self._sql_format(self.name)}' WHERE key='name'")
+        self.execute(f"UPDATE info SET value='{self._sql_format(self.description)}' WHERE key='description'")
+        self.execute(f"UPDATE info SET value='{self._time_system}' WHERE key='time_system'")
+        self.execute(f"UPDATE info SET value='{self._date.timestamp()}' WHERE key='date'")
+        self.execute(f"UPDATE info SET value='{self.creation_date.timestamp()}' WHERE key='creation_date'")
+        self.execute(f"UPDATE info SET value='{self.last_save_date.timestamp()}' WHERE key='last_save_date'")
+
         self._save_submodel([self._river])
         self.commit()