Model Wrapper

A model wrapper is an utility used to wrap a database model and provide a consistent interface over it. It allows automatically adding new rows to the database, updating existing rows, and deleting rows.

You can use the basic functionality of the model wrapper by using the rxe.model_wrapper function. This function takes a database model and returns a wrapper object that can be used to interact with the model.

By default the model_wrapper use the infinite rows model from AgGrid. As the user scrolls, the wrapper automatically loads windows of rows from the database instead of loading the whole table into memory. The cache size can be tuned with the max_blocks_in_cache and cache_block_size props.

The model passed as model_class must exactly match the schema of the database table backing it, or querying will fail. In particular, don't invent a primary key that the actual table doesn't have.

If the default model wrapper does not fit your needs, you can create a custom model wrapper by subclassing the rxe.ModelWrapper class. This allows you to customize the behavior of the model wrapper to fit your specific use case.

In the custom model wrapper, you can override the following methods:

• _get_columns_defs
• _get_data
• _row_count
• on_value_setter

to modify how the model wrapper will behave.

A custom wrapper is rendered with its create classmethod:

By default there is no authentication checking for any database operation performed through the grid — inserts, updates, and deletes are open to any user who can reach the page. To restrict operations, override the _is_authorized method in a ModelWrapper subclass:

Override _get_column_defs to adjust the generated column definitions — for example to disable filtering or sorting on a specific field:

The toolbar UI can be customized as well: override the _top_toolbar, _delete_button, and _add_dialog classmethods to replace the default add/delete controls with your own components.

The SSRM model wrapper, used with rxe.model_wrapper_ssrm, is a version of the model wrapper that allows you to use the ServerSideRowModel of AgGrid.

In the same way you can extend the default model wrapper, you can extend the SSRM custom model wrapper by subclassing the rxe.ModelWrapperSSRM class. This allows you to customize the behavior of the model wrapper to fit your specific use case.

The overridable methods are the same as the standard model wrapper.