Feature/#709 user man (#1285)

* Improve Data node ref man

* Improve Task ref man

* Improve Scenario ref man

* Apply suggestions from code review

Co-authored-by: Đỗ Trường Giang <do.giang@avaiga.com>

* linter

* formatting

---------

Co-authored-by: Đỗ Trường Giang <do.giang@avaiga.com>

taipy/core/data/data_node.py

@@ -65,7 +65,37 @@ class DataNode(_Entity, _Labeled):
     SQL Data Node, CSV Data Node, ...).
 
     !!! note
-        It is recommended not to instantiate subclasses of `DataNode` directly.
+        It is not recommended to instantiate subclasses of `DataNode` directly. Instead,
+        you have two ways:
+
+        1. Create a Scenario using the `create_scenario()^` function. Related data nodes
+            will be created automatically. Please refer to the `Scenario^` class for more
+            information.
+        2. Configure a `DataNodeConfig^` with the various configuration methods form `Config^`
+            and use the `create_global_data_node()^` function as illustrated in the following
+            example.
+
+    !!! Example
+
+        ```python
+        import taipy as tp
+        from taipy import Config
+
+        # Configure a global data node
+        dataset_cfg = Config.configure_data_node("my_dataset", scope=tp.Scope.GLOBAL)
+
+        # Instantiate a global data node
+        dataset = tp.create_global_data_node(dataset_cfg)
+
+        # Retrieve the list of all data nodes
+        all_data_nodes = tp.get_data_nodes()
+
+        # Write the data
+        dataset.write("Hello, World!")
+
+        # Read the data
+        print(dataset.read())
+        ```
 
     Attributes:
         config_id (str): Identifier of the data node configuration. It must be a valid Python
@@ -78,10 +108,11 @@ class DataNode(_Entity, _Labeled):
         parent_ids (Optional[Set[str]]): The set of identifiers of the parent tasks.
         last_edit_date (datetime): The date and time of the last modification.
         edits (List[Edit^]): The list of Edits (an alias for dict) containing metadata about each
-            data edition including but not limited to timestamp, comments, job_id:
-            timestamp: The time instant of the writing
-            comments: Representation of a free text to explain or comment on a data change
-            job_id: Only populated when the data node is written by a task execution and corresponds to the job's id.
+            data edition including but not limited to:
+                <ul><li>timestamp: The time instant of the writing </li>
+                <li>comments: Representation of a free text to explain or comment on a data change</li>
+                <li>job_id: Only populated when the data node is written by a task execution and
+                    corresponds to the job's id.</li></ul>
             Additional metadata related to the edition made to the data node can also be provided in Edits.
         version (str): The string indicates the application version of the data node to
             instantiate. If not provided, the current version is used.

taipy/core/scenario/scenario.py

@@ -55,6 +55,40 @@ class Scenario(_Entity, Submittable, _Labeled):
     solve the Business case. It also holds a set of additional data nodes (instances of `DataNode` class)
     for extra data related to the scenario.
 
+    !!! note
+
+        It is not recommended to instantiate a `Scenario` directly. Instead, it should be
+        created with the `create_scenario()^` function.
+
+    !!! Example
+
+        ```python
+        import taipy as tp
+        from taipy import Config
+
+        def by_two(x: int):
+            return x * 2
+
+        # Configure scenarios
+        input_cfg = Config.configure_data_node("my_input")
+        result_cfg = Config.configure_data_node("my_result")
+        task_cfg = Config.configure_task("my_double", function=by_two, input=input_cfg, output=result_cfg)
+        scenario_cfg = Config.configure_scenario("my_scenario", task_configs=[task_cfg])
+
+        # Create a new scenario from the configuration
+        scenario = tp.create_scenario(scenario_cfg)
+
+        # Write the input data and submit the scenario
+        scenario.my_input.write(3)
+        scenario.submit()
+
+        # Read the result
+        print(scenario.my_result.read())  # Output: 6
+
+        # Retrieve all scenarios
+        all_scenarios = tp.get_scenarios()
+        ```
+
     Attributes:
         config_id (str): The identifier of the `ScenarioConfig^`.
         tasks (Set[Task^]): The set of tasks.

taipy/core/task/task.py

@@ -33,6 +33,46 @@ class Task(_Entity, _Labeled):
     A `Task` brings together the user code as function, the inputs and the outputs as data nodes
     (instances of the `DataNode^` class).
 
+    !!! note
+        It is not recommended to instantiate a `Task` directly. Instead, it should be
+        created with the `create_scenario()^` function. When creating a `Scenario^`,
+        the related data nodes and tasks are created automatically. Please refer to
+        the `Scenario^` class for more information.
+
+    !!! Example
+
+        ```python
+        import taipy as tp
+        from taipy import Config
+
+        def by_two(x: int):
+            return x * 2
+
+        # Configure data nodes, tasks and scenarios
+        input_cfg = Config.configure_data_node("my_input", default_data=2)
+        result_cfg = Config.configure_data_node("my_result")
+        task_cfg = Config.configure_task("my_double", function=by_two, input=input_cfg, output=result_cfg)
+        scenario_cfg = Config.configure_scenario("my_scenario", task_configs=[task_cfg])
+
+        # Instantiate a task along with a scenario
+        sc = tp.create_scenario(scenario_cfg)
+
+        # Retrieve task and data nodes from scenario
+        task_input = sc.my_input
+        double_task = sc.my_double
+        task_result = sc.my_result
+
+        # Write the input data and submit the task
+        task_input.write(3)
+        double_task.submit()
+
+        # Read the result
+        print(task_result.read())  # Output: 6
+
+        # Retrieve the list of all tasks
+        all_tasks = tp.get_tasks()
+        ```
+
     Attributes:
         config_id (str): The identifier of the `TaskConfig^`.
         properties (dict[str, Any]): A dictionary of additional properties.