Data Grid - Server-side data 🚧
The data grid server-side data.
Overview
Managing server-side data efficiently in a React application can become complex as the dataset grows.
Without a dedicated module that abstracts its complexities, developers often face challenges related to manual data fetching, pagination, sorting, and filtering, and it often gets trickier to tackle performance issues, which can lead to a poor user experience.
Have a look at an example:
Example scenario
Imagine having a data grid that displays a list of users. The data grid has pagination enabled and the user can sort the data by clicking on the column headers and also apply filters.
The data grid is configured to fetch data from the server whenever the user changes the page or updates filtering or sorting.
const [rows, setRows] = React.useState([]);
const [paginationModel, setPaginationModel] = React.useState({
page: 0,
pageSize: 10,
});
const [filterModel, setFilterModel] = React.useState({ items: [] });
const [sortModel, setSortModel] = React.useState([]);
React.useEffect(() => {
const fetcher = async () => {
// fetch data from server
const data = await fetch('https://my-api.com/data', {
method: 'GET',
body: JSON.stringify({
page: paginationModel.page,
pageSize: paginationModel.pageSize,
sortModel,
filterModel,
}),
});
setRows(data.rows);
};
fetcher();
}, [paginationModel, sortModel, filterModel]);
<DataGridPro
columns={columns}
pagination
sortingMode="server"
filterMode="server"
paginationMode="server"
onPaginationModelChange={setPaginationModel}
onSortModelChange={setSortModel}
onFilterModelChange={setFilterModel}
/>;
This example only scratches the surface with a lot of problems still unsolved like:
- Performance optimization
- Caching data/deduping requests
- More complex use-cases on the server like grouping, tree data, etc.
- Server side row editing
- Lazy loading of data
- Handling updates to the data like row editing, row deletion, etc.
- Refetching data on-demand
Trying to solve these problems one after the other can make the code complex and hard to maintain.
Data source
A very common pattern to solve these problems is to use a centralized data source. A data source is an abstraction layer that sits between the data grid and the server. It provides a simple interface to the data grid to fetch data and update it. It handles a lot of the complexities related to server-side data fetching. Let's delve a bit deeper into how it will look like.
Overview
The Data Grid already supports manual server-side data fetching for features like sorting, filtering, etc. In order to make it more powerful and simple to use, the grid will support a data source interface that you can implement with your existing data fetching logic.
The datasource will work with all the major data grid features which require server-side data fetching such as sorting, filtering, pagination, grouping, etc.
Usage
The data grid server-side data source has an initial set of required methods that you need to implement. The data grid will call these methods internally when the data is required for a specific page.
interface DataSource {
/**
Fetcher Functions:
- `getRows` is required
- `updateRow` is optional
`getRows` will be used by the grid to fetch data for the current page or children for the current parent group
It may return a `rowCount` to update the total count of rows in the grid
*/
getRows(params: GetRowsParams): Promise<GetRowsResponse>;
updateRow?(updatedRow: GridRowModel): Promise<any>;
}
Here's how the code will look like for the above example when implemented with data source:
const customDataSource: DataSource = {
getRows: async (params: GetRowsParams): GetRowsResponse => {
// fetch data from server
const response = await fetch('https://my-api.com/data', {
method: 'GET',
body: JSON.stringify(params),
});
const data = await response.json();
// return the data and the total number of rows
return {
rows: data.rows,
rowCount: data.totalCount,
};
},
}
<DataGridPro
columns={columns}
dataSource={customDataSource}
pagination
/>
Not only the code has been reduced significantly, it has removed the hassle of managing controlled states and data fetching logic too.
On top of that, the data source will also handle a lot of other aspects like caching and deduping of requests.
Loading data
The method dataSource.getRows will be called with the GetRowsParams object whenever some data from the server is needed. This object contains all the information that you need to fetch the data from the server.
Since previously, the data grid did not support internal data fetching, the rows prop was the way to pass the data to the grid. However, with server-side data, the rows prop is no longer needed. Instead, the data grid will call the getRows method whenever it needs to fetch data.
Here's the GetRowsParams object for reference:
interface GetRowsParams {
sortModel: GridSortModel;
filterModel: GridFilterModel;
/**
* Alternate to `start` and `end`, maps to `GridPaginationModel` interface
*/
paginationModel: GridPaginationModel;
/**
* First row index to fetch (number) or cursor information (number | string)
*/
start: number | string; // first row index to fetch or cursor information
/**
* Last row index to fetch
*/
end: number; // last row index to fetch
/**
* Array of keys returned by `getGroupKey` of all the parent rows until the row for which the data is requested
* `getGroupKey` prop must be implemented to use this
* Useful for `treeData` and `rowGrouping` only
*/
groupKeys: string[];
/**
* List of grouped columns (only applicable with `rowGrouping`)
*/
groupFields: GridColDef['field'][]; // list of grouped columns (`rowGrouping`)
}
And here's the GetRowsResponse object for reference:
interface GetRowsResponse {
/**
* Subset of the rows as per the passed `GetRowsParams`
*/
rows: GridRowModel[];
/**
* To reflect updates in total `rowCount` (optional)
* Useful when the `rowCount` is inaccurate (e.g. when filtering) or not available upfront
*/
rowCount?: number;
/**
* Additional `pageInfo` to help the grid determine if there are more rows to fetch (corner-cases)
* `hasNextPage`: When row count is unknown/inaccurate, if `truncated` is set or rowCount is not known, data will keep loading until `hasNextPage` is `false`
* `truncated`: To reflect `rowCount` is inaccurate (will trigger `x-y of many` in pagination after the count of rows fetched is greater than provided `rowCount`)
* It could be useful with:
* 1. Cursor based pagination:
* When rowCount is not known, grid will check for `hasNextPage` to determine
* if there are more rows to fetch.
* 2. Inaccurate `rowCount`:
* `truncated: true` will let the grid know that `rowCount` is estimated/truncated.
* Thus `hasNextPage` will come into play to check more rows are available to fetch after the number becomes >= provided `rowCount`
*/
pageInfo?: {
hasNextPage?: boolean;
truncated?: number;
};
}
Updating data
If provided, the method dataSource.updateRow will be called with the GridRowModel object whenever the user edits a row. This method is optional and you can skip it if you don't need to update the data on the server. It will work in a similar way as the processRowUpdate prop.
Data Grid props
These data grid props will work with the server-side data source:
dataSource: DataSource: the data source object that you need to implementrows: will be ignored, could be skipped whendataSourceis providedrowCount: will be used to identify the total number of rows in the grid, if not provided, the grid will check for the GetRowsResponse.rowCount value, unless the feature being used is infinite loading where norowCountis available at all.
Props related to grouped data (treeData and rowGrouping):
getGroupKey(row: GridRowModel): stringwill be used by the grid to group rows by their parent group This effectively replaces
getTreeDataPath. Consider this structure:- (1) Sarah // groupKey 'Sarah' - (2) Thomas // groupKey 'Thomas'When (2) is expanded, the
getRowsfunction will be called with group keys['Sarah', 'Thomas'].hasChildren?(row: GridRowModel): booleanWill be used by the grid to determine if a row has children on server
getChildrenCount?: (row: GridRowModel) => numberWill be used by the grid to determine the number of children of a row on server
Existing server-side features
The server-side data source will change a bit the way existing server-side features like filtering, sorting, and pagination work.
Without data source:
When there's no data source, the features filtering, sorting, pagination will work on client by default. In order for them to work with server-side data, you need to set them to server explicitly and listen to the onFilterModelChange, onSortModelChange, onPaginationModelChange events to fetch the data from the server based on the updated variables.
<DataGrid
columns={columns}
rows={rows}
pagination
sortingMode="server"
filterMode="server"
paginationMode="server"
onPaginationModelChange={(newPaginationModel) => {
// fetch data from server
}}
onSortModelChange={(newSortModel) => {
// fetch data from server
}}
onFilterModelChange={(newFilterModel) => {
// fetch data from server
}}
/>
With data source:
However, with a valid data source passed the features filtering, sorting, pagination will automatically be set to server.
You just need to implement the getRows method and the data grid will call the getRows method with the proper params whenever it needs data.
<DataGridPro
columns={columns}
dataSource={customDataSource} // this automatically means `sortingMode="server"`, `filterMode="server"`, `paginationMode="server"`
/>
Caching
The data grid will cache the data it receives from the server. This means that if the user navigates to a page that has already been fetched, the grid will not call the getRows function again. This is to avoid unnecessary calls to the server.