Blazor Grid State Persistence
The Ignite UI for Blazor State Persistence in Blazor Grid allows developers to easily save and restore the grid state. When the IgbGridState
is applied on the Blazor IgbGrid
, it exposes the GetStateAsString
and ApplyStateFromString
methods that developers can use to achieve state persistence in any scenario.
Supported Features
IgbGridState
directive supports saving and restoring the state of the following features:
- Sorting
- Filtering
- Advanced Filtering
- Paging
- CellSelection
- RowSelection
- ColumnSelection
- RowPinning
- Expansion
- GroupBy
- Columns
- Multi column headers
- Columns order
- Column properties defined by the
IColumnState
interface.
Usage
The GetStateAsString
returns a serialized JSON string, so developers can just take it and save it on any data storage (database, cloud, browser localStorage, etc).
The developer may choose to get only the state for a certain feature/features, by passing in an array with feature names as an argument. Empty array will result to using the default state options.
<IgbGrid>
<IgbGridState @ref="gridState"></IgbGridState>
</IgbGrid>
@code {
// get all features` state in a serialized JSON string
string stateString = gridState.GetStateAsString(new string[0]);
// get the sorting and filtering expressions
string sortingFilteringStates = gridState.GetStateAsString(new string[] { "sorting", "filtering" });
}
ApplyStateFromString
- The method accepts a serialized JSON string as argument and will restore the state of each feature found in the JSON string or specified features as second argument.
gridState.ApplyStateFromString(gridStateString, new string[0]);
gridState.ApplyStateFromString(sortingFilteringStates, new string[0])
The Options
object implements the IgbGridStateOptions
interface, i.e. for every key, which is the name of a certain feature, there is the boolean value indicating if this feature state will be tracked. GetStateAsString
methods will not put the state of these features in the returned value and ApplyStateFromString
methods will not restore state for them.
gridState.Options = new IgbGridStateOptions
{
CellSelection = false,
Sorting = false
};
The simple to use single-point API's allows to achieve a full state persistence functionality in just a few lines of code. Copy paste the code from below - it will save the grid state in the browser LocalStorage
object every time the user leaves the current page. Whenever the user returns to main page, the grid state will be restored. No more need to configure those complex advanced filtering and sorting expressions every time to get the data you want - do it once and have the code from below do the rest for your users:
@using IgniteUI.Blazor.Controls
@using Newtonsoft.Json
@implements IDisposable
@inject IJSRuntime JS
@inject NavigationManager Navigation
<IgbGrid Rendered="OnGridRendered">
<IgbGridState @ref="gridState"></IgbGridState>
<IgbColumn Field="ContactName" Header="Name" MinWidth="200px" ></IgbColumn>
<IgbColumn Field="ContactTitle" Header="Title" MinWidth="200px" Sortable="true" Filterable="true" Groupable="true"></IgbColumn>
<IgbColumn Field="CompanyName" Header="Company" MinWidth="200px" Sortable="true" Filterable="true" Groupable="true"></IgbColumn>
</IgbGrid>
@code {
protected override void OnAfterRender(bool firstRender)
{
Navigation.LocationChanged += OnLocationChanged;
}
void OnLocationChanged(object sender, LocationChangedEventArgs e)
{
SaveGridState();
}
void IDisposable.Dispose()
{
// Unsubscribe from the event when our component is disposed
Navigation.LocationChanged -= OnLocationChanged;
}
void OnGridRendered()
{
RestoreGridState();
}
async void SaveGridState() {
string state = gridState.getStateAsString(new string[0]);
await JS.InvokeVoidAsync("window.localStorage.setItem", "grid-state", state);
}
async void RestoreGridState() {
string state = await JS.InvokeAsync<string>("window.localStorage.getItem", "grid-state");
if (state) {
gridState.ApplyStateFromString(state, new string[0]);
}
}
}
Demo
Limitations
GetStateAsString
method uses JSON.stringify() method to convert the original objects to a JSON string. JSON.stringify() does not support Functions, thats why theIgbGridState
component will ignore the columnsFormatter
,Filters
,Summaries
,SortStrategy
,CellClasses
,CellStyles
,HeaderTemplate
andBodyTemplate
properties.