Merge pull request #658 from Avaiga/feature/migration-path-30

feat: add taipy core migration path

docs/migration.md

@@ -4,50 +4,84 @@ hide:
   - navigation
 ---
 
-This documentation page lists the migration paths of Taipy releases as they
-were published.
+This documentation page lists the migration paths of Taipy releases as they were published.
 
 # From 2.x to 3.0
 
-In Taipy GUI 3.0, the `on_action` callback signature was unified across all controls: the third
-parameter (*action*) was dropped. The *payload* dictionary parameter that used to be in fourth
-place is now in third place and contains an *action* key that is set to the action name if you used
-to use *action*.
+1. In Taipy GUI 3.0, the `on_action` callback signature was unified across all controls: the third
+    parameter (*action*) was dropped. The *payload* dictionary parameter that used to be in fourth
+    place is now in third place and contains an *action* key that is set to the action name if you 
+    used to use *action*.
+
+2. In Taipy Core 3.0 we deprecated the `pipeline` concept in favor of 
+    [sequence](./manuals/core/entities/sequence-mgt.md). This also means that `configure_pipeline` 
+    from Taipy Config was removed, making it necessary to update your config code. Take for 
+    instance the following config on `Taipy 2.4`:
+
+    ```python title="config.py from Taipy 2.4 edition"
+    from taipy import Config
+
+    # Omiting multiply_task_cfg creation
+
+    pipeline_cfg = Config.configure_pipeline(
+        "pipeline_1",
+        task_configs=[multiply_task_cfg]
+    )
+
+    scenario_cfg = Config.configure_scenario(
+        "multiply_scenario",
+        pipeline_configs=[pipeline_cfg]
+    )
+    ```
+
+    Now, `configure_scenario` takes task configs as parameter in place of pipeline configs, so to 
+    update the config above to `Taipy 3.0` is just a matter of:
+
+    ```python title="config.py from Taipy 3.0 edition"
+    from taipy import Config
+
+    # Omiting multiply_task_cfg creation
+
+    scenario_cfg = Config.configure_scenario(
+        "multiply_scenario",
+        task_configs=[multiply_task_cfg]
+    )
+    ```
+
+    After migrating the code, we recommend that you take advantage of `Taipy CLI`
+    [migration tool](./manuals/cli/migrate-entities.md).
+
 
 # From 2.0 to 2.1
 
-In Taipy version 2.1, the version management system has been introduced. For
-applications created with a Taipy Core version &#8804 2.0, the first time it
-runs with version 2.1 or later, no version exists, and so legacy entities are not
-attached to any version. The overall principle is to create a version the first
-time the application runs with Taipy 2.1 or later and to assign all the old entities
-to this version. Depending on the mode used to run the application,
-(Refer to [versioning documentation](manuals/core/versioning/index.md)
-for details) we propose the following migration paths:
+In Taipy version 2.1, the version management system has been introduced. For applications 
+created with a Taipy Core version &#8804 2.0, the first time it runs with version 2.1 or later, 
+no version exists, and so legacy entities are not attached to any version. The overall principle 
+is to create a version the first time the application runs with Taipy 2.1 or later and to assign 
+all the old entities to this version. Depending on the mode used to run the application,
+(Refer to [versioning documentation](manuals/core/versioning/index.md) for details) we propose 
+the following migration paths:
 
 ## Using default or development mode
 
-Please refer to the [Development mode](manuals/core/versioning/development_mode.md)
+Please refer to the [Development mode](manuals/core/versioning/development_mode.md) 
 documentation page for more details on how to run Taipy in development mode.
 
-The first time you run the application with Taipy 2.1 or later, if you use the
-_development_ mode which is the default mode, Taipy automatically creates an
-_experiment_ version with the current configuration and assigns all legacy
-entities to it. The version is named "LEGACY-VERSION". Depending on how you
-want to handle legacy entities, you can now manage your newly created version
-using the version management system. Please refer to the
-[Version management system](manuals/core/versioning/index.md) documentation page
-for more details.
+The first time you run the application with Taipy 2.1 or later, if you use the _development_ 
+mode which is the default mode, Taipy automatically creates an _experiment_ version with the 
+current configuration and assigns all legacy entities to it. The version is named 
+"LEGACY-VERSION". Depending on how you want to handle legacy entities, you can now manage your 
+newly created version using the version management system. Please refer to the
+[Version management system](manuals/core/versioning/index.md) documentation page for more details.
 
 ## Using experiment or production mode
 
 Please refer to the [Experiment mode](manuals/core/versioning/experiment_mode.md) or
-[Production mode](manuals/core/versioning/experiment_mode.md) documentation pages
-for more details on how to run Taipy in experiment or production mode.
-
-The first time you run the application with Taipy 2.1 or later, if you use
-_experiment_ or _production_ mode, you can simply provide a version name to create
-a new version. All legacy entities are automatically attached to this version.
-You can now manage your newly created version using the version management system.
-Please refer to the [Version management system](manuals/core/versioning/index.md)
-documentation page for more details.
+[Production mode](manuals/core/versioning/experiment_mode.md) documentation pages for more 
+details on how to run Taipy in experiment or production mode.
+
+The first time you run the application with Taipy 2.1 or later, if you use _experiment_ or 
+_production_ mode, you can simply provide a version name to create a new version. All legacy 
+entities are automatically attached to this version. You can now manage your newly created 
+version using the version management system. Please refer to the 
+[Version management system](manuals/core/versioning/index.md) documentation page for more details.