fix(sdk): fix load v1 if present placeholder (#7765)

* fix load v1 if present placeholder

* add test for load v1 if present placeholder

sdk/python/kfp/components/structures.py

@@ -841,18 +841,20 @@ class ComponentSpec(base_model.BaseModel):
                         input_name=utils.sanitize_input_name(
                             if_placeholder_values['cond']['isPresent']),
                         then=[
-                            convert_str_or_dict_to_placeholder(val)
+                            convert_str_or_dict_to_placeholder(
+                                convert_v1_if_present_placholder_to_v2(val))
                             for val in if_placeholder_values_then
                         ],
                         otherwise=[
-                            convert_str_or_dict_to_placeholder(val)
+                            convert_str_or_dict_to_placeholder(
+                                convert_v1_if_present_placholder_to_v2(val))
                             for val in if_placeholder_values_else
                         ]))
 
             elif 'concat' in arg:
-
                 return ConcatPlaceholder(items=[
-                    convert_str_or_dict_to_placeholder(val)
+                    convert_str_or_dict_to_placeholder(
+                        convert_v1_if_present_placholder_to_v2(val))
                     for val in arg['concat']
                 ])
             elif isinstance(arg, (ValidCommandArgTypes, dict)):

sdk/python/kfp/components/structures_test.py

@@ -91,6 +91,30 @@ COMPONENT_SPEC_CONCAT_PLACEHOLDER = structures.ComponentSpec(
     inputs={'input_prefix': structures.InputSpec(type='String')},
 )
 
+V1_YAML_NESTED_PLACEHOLDER = textwrap.dedent("""\
+    name: component_nested
+    implementation:
+      container:
+        args:
+        - concat:
+            - --arg1
+            - if:
+                cond:
+                    isPresent: input_prefix
+                else:
+                - --arg2
+                - default
+                - concat:
+                    - --arg1
+                    - {inputValue: input_prefix}
+                then:
+                - --arg1
+                - {inputValue: input_prefix}
+        image: alpine
+    inputs:
+    - {name: input_prefix, optional: false, type: String}
+    """)
+
 COMPONENT_SPEC_NESTED_PLACEHOLDER = structures.ComponentSpec(
     name='component_nested',
     implementation=structures.Implementation(
@@ -287,6 +311,10 @@ sdkVersion: kfp-2.0.0-alpha.2
             'yaml': V1_YAML_CONCAT_PLACEHOLDER,
             'expected_component': COMPONENT_SPEC_CONCAT_PLACEHOLDER
         },
+        {
+            'yaml': V1_YAML_NESTED_PLACEHOLDER,
+            'expected_component': COMPONENT_SPEC_NESTED_PLACEHOLDER
+        },
     )
     def test_component_spec_placeholder_load_from_v2_component_yaml(
             self, yaml, expected_component):