sonic-yang-mgmt: new public function of load_module_str_name() to prevent call into libyang by sonic-utilities

Author: bradh352

src/sonic-yang-mgmt/sonic_yang.py

@@ -476,6 +476,23 @@ def _find_data_nodes(self, data_xpath):
     def _find_schema_dependencies(self, match_path, match_ancestors: bool=False):
         return self.ctx.find_backlinks_paths(match_path, match_ancestors=match_ancestors)
 
+    """
+    load_module_str_name(): load a module based on the provided string and return
+                            the loaded module name.  This is needed by
+                            sonic-yang-modules to prevent direct dependency on
+                            libyang.
+    input: yang_module_str yang-formatted module
+    returns: module name on success, exception on failure
+    """
+    def load_module_str_name(yang_module_str):
+        try:
+            module = self.ctx.parse_module_str(yang_module_str)
+        except Exception as e:
+            self.fail(e);
+        else:
+            return module.name()
+
+        return None
 
     """
     find_data_dependencies(): find the data dependencies from data xpath  (Public)