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GridBlazor supports CRUD forms to add, edit, view and delete items for Blazor server-side projects.
These are the supported features:
You can enable CRUD using the Crud(bool enabled, ICrudDataService crudDataService) method of the GridClient object:
var client = new GridClient<Order>(HttpClient, url, query, false, "ordersGrid", c =>
ColumnCollections.OrderColumnsWithCrud(c, NavigationManager.BaseUri), locale)
.Crud(true, orderService)
You can also enable CRUD depending on a condition for each row using the Crud(bool createEnabled, Func<T, bool> enabled, ICrudDataService crudDataService) method:
var client = new GridClient<Order>(HttpClient, url, query, false, "ordersGrid", c =>
ColumnCollections.OrderColumnsWithCrud(c, NavigationManager.BaseUri), locale)
.Crud(true, r => r.Customer.IsVip, orderService)
The create form can only be enabled using a bool parameter. But the read, update and delete forms can be enabled using a function that returns a bool.
Note: All 4 crud forms can be enabled at the same time with the former methods, but you can enable one by one using Crud(bool create, bool read, bool update, bool delete, ICrudDataService<T> crudDataService) or Crud(bool createEnabled, Func<T, bool> readEnabled, Func<T, bool> updateEnabled, Func<T, bool> deleteEnabled, ICrudDataService<T> crudDataService) methods.
The parameter crudDataService of the Crud method must be a class that implements the ICrudDataService interface. This interface has 4 methods:
Task<T> Get(params object[] keys);Task Insert(T item);Task Update(T item);Task Delete(params object[] keys);
one for each CRUD operation.This is an example of those 4 methods:
public async Task<Order> Get(params object[] keys)
{
using (var context = new NorthwindDbContext(_options))
{
int orderId;
int.TryParse(keys[0].ToString(), out orderId);
var repository = new OrdersRepository(context);
return await repository.GetById(orderId);
}
}
public async Task Insert(Order item)
{
using (var context = new NorthwindDbContext(_options))
{
var repository = new OrdersRepository(context);
await repository.Insert(item);
repository.Save();
}
}
public async Task Update(Order item)
{
using (var context = new NorthwindDbContext(_options))
{
var repository = new OrdersRepository(context);
await repository.Update(item);
repository.Save();
}
}
public async Task Delete(params object[] keys)
{
using (var context = new NorthwindDbContext(_options))
{
var order = await Get(keys);
var repository = new OrdersRepository(context);
repository.Delete(order);
repository.Save();
}
}
The best way to avoid threading and cache issues for Blazor Server App projects is to create a DbContext inside each method with using. Dependency injection for DbContext can produce threading and cache issues.
The column definition must include the primary keys:
If the grid model includes foreign keys, the column definition should include them using the SetSelectField in order to get the options for the <select> element.
The SetSelectField method has 3 required parameters:
| Parameter | Description |
|---|---|
| enabled | boolean to configure if the field is shown as a <select> html element |
| expression | function to get the selected value for update and delete forms (it must return an string value) |
| selectItemExpr | function to get the values and titles to be shown in the drop-down of create and update forms (it must return an IEnumerable<SelectItem>) |
The type of fields currently supported as foreign keys are:
This is an example of function to get values and title for a drop-down:
public IEnumerable<SelectItem> GetAllEmployees()
{
using (var context = new NorthwindDbContext(_options))
{
EmployeeRepository repository = new EmployeeRepository(context);
return repository.GetAll()
.Select(r => new SelectItem(r.EmployeeID.ToString(), r.EmployeeID.ToString() + " - "
+ r.FirstName + " " + r.LastName))
.ToList();
}
}
As explained for the 4 CRUD methods, the best way to avoid threading and cache issues for Blazor Server App projects is to create a DbContext inside the function with using.
Other fields that you want to be shown as dropdowns with a closed list can also be configured with the SetSelectField method.
All fields to be included in the CRUD forms but not in the grid as columns should be configured as hidden (e.g. Add(o => o.RequiredDate, true)).
All columns required to be included in the Update form as read only should be configured using the SetReadOnlyOnUpdate(true) method.
If a column is a date that has to be shown as date, time, week, month or datetime-local in the CRUD forms, the column definition should use the SetInputType method in order to get the correct format.
If a column is a string that has to be shown as <textarea> in the CRUD forms, the column definition should use the SetInputType method in order to get the correct html element.
The SetInputType method has 1 required parameter:
| Parameter | Description |
|---|---|
| inputType |
InputType enum. Its value can be InputType.TextArea, InputType.Date, InputType.Time, InputType.Month, InputType.Week or InputType.DateTimeLocal
|
You can also add components on the CRUD forms using the RenderCrudComponentAs<TComponent> method. You must define these columns as Hidden to show them just on CRUD forms.
And finally all columns included in the grid but not in the CRUD forms should be configured as "CRUD hidden" using the SetCrudHidden(true) method.
Notes:
SetCrudHidden(bool create, bool read, bool update, bool delete) method to configure the columns that will be hidden on each type of form.RenderCrudComponentAs<TCreateComponent, TReadComponent, TUpdateComponent, TDeleteComponent> method to configure the components that will be shown on each type of form. Id you don't want to show any component for a specific type of form you must use NullComponent
This is an example of column definition:
Action<IGridColumnCollection<Order>> columns = c =>
{
c.Add(o => o.OrderID).SetPrimaryKey(true);
c.Add(o => o.CustomerID, true).SetSelectField(true, o => o.Customer.CustomerID + " - " + o.Customer.CompanyName,
customerService.GetAllCustomers);
c.Add(o => o.EmployeeID, true).SetSelectField(true, o => o.Employee.EmployeeID.ToString()
+ " - " + o.Employee.FirstName + " " + o.Employee.LastName, employeeService.GetAllEmployees);
c.Add(o => o.ShipVia, true).SetSelectField(true, o => o.Shipper == null ? "" : o.Shipper.ShipperID.ToString()
+ " - " + o.Shipper.CompanyName, shipperService.GetAllShippers);
c.Add(o => o.OrderDate, "OrderCustomDate").Titled(SharedResource.OrderCustomDate).Format("{0:yyyy-MM-dd}");
c.Add(o => o.Customer.CompanyName).Titled(SharedResource.CompanyName).SetReadOnlyOnUpdate(true);
c.Add(o => o.Customer.ContactName).Titled(SharedResource.ContactName).SetCrudHidden(true);
c.Add(o => o.Freight).Titled(SharedResource.Freight).Format("{0:F}");
c.Add(o => o.Customer.IsVip).Titled(SharedResource.IsVip).RenderValueAs(o => o.Customer.IsVip ? "Yes" : "No").SetCrudHidden(true);
c.Add(o => o.RequiredDate, true).Format("{0:yyyy-MM-dd}");
c.Add(o => o.ShippedDate, true).Format("{0:yyyy-MM-dd}");
c.Add(o => o.ShipName, true);
c.Add(o => o.ShipAddress, true);
c.Add(o => o.ShipCity, true);
c.Add(o => o.ShipPostalCode, true);
c.Add(o => o.ShipRegion, true);
c.Add(o => o.ShipCountry, true);
};
This is an example of a grid using CRUD:
And this is an auto-genereated edit form:
If you want to use custom forms you can enable them using the SetCreateComponent, SetReadComponent, SetUpdateComponent and SetDeleteComponent methods of the GridClient object:
var client = new GridClient<Order>(q => orderService.GetOrdersGridRows(columns, q), query, false, "ordersGrid", columns, locale)
.Crud(true, orderService)
.SetCreateComponent<OrderCreateComponent>()
.SetReadComponent<OrderReadComponent>()
.SetUpdateComponent<OrderUpdateComponent>()
.SetDeleteComponent<OrderDeleteComponent>();
You can define all custom forms or just some of them. If you don't define a custom form for one of the enabled operations an auto-generated form will be used instead.
And finally you will have to create a Blazor component for the custom form. This is an example of edit form:
@using GridBlazor
@using GridBlazor.Resources
@using GridBlazorServerSide.Models
@inherits GridUpdateComponentBase<Order>
<h1>@Strings.Add Order</h1>
<EditForm Model="@Item" OnValidSubmit="@UpdateItem">
<DataAnnotationsValidator />
<ValidationSummary />
<div class="form-horizontal">
<div class="form-group">
<label for="OrderID" class="control-label col-md-2">OrderID: </label>
<div class="col-md-5">
<InputNumber id="OrderID" class="form-control" readonly="readonly" @bind-Value="Item.OrderID" />
</div>
</div>
<div class="form-group">
<label for="CustomerID" class="control-label col-md-2">Customer Id: </label>
<div class="col-md-5">
<InputText id="CustomerID" class="form-control" @bind-Value="Item.CustomerID" />
</div>
</div>
<div class="form-group">
<label for="EmployeeID" class="control-label col-md-2">Employee Id: </label>
<div class="col-md-5">
<InputNumber id="EmployeeID" class="form-control" @bind-Value="Item.EmployeeID" />
</div>
</div>
<div class="form-group">
<label for="ShipVia" class="control-label col-md-2">Ship Via: </label>
<div class="col-md-5">
<InputNumber id="ShipVia" class="form-control" @bind-Value="Item.ShipVia" />
</div>
</div>
<div class="form-group">
<label for="RequiredDate" class="control-label col-md-2">Required Date: </label>
<div class="col-md-5">
<InputDate id="RequiredDate" class="form-control" @bind-Value="Item.RequiredDate" />
</div>
</div>
<div class="form-group">
<label for="ShippedDate" class="control-label col-md-2">Shipped Date: </label>
<div class="col-md-5">
<InputDate id="ShippedDate" class="form-control" @bind-Value="Item.ShippedDate" />
</div>
</div>
<div class="form-group">
<label for="ShipName" class="control-label col-md-2">Ship Name: </label>
<div class="col-md-5">
<InputText id="ShipName" class="form-control" @bind-Value="Item.ShipName" />
</div>
</div>
<div class="form-group">
<label for="ShipAddress" class="control-label col-md-2">Ship Address: </label>
<div class="col-md-5">
<InputText id="ShipAddress" class="form-control" @bind-Value="Item.ShipAddress" />
</div>
</div>
<div class="form-group">
<label for="ShipCity" class="control-label col-md-2">Ship City: </label>
<div class="col-md-5">
<InputText id="ShipCity" class="form-control" @bind-Value="Item.ShipCity" />
</div>
</div>
<div class="form-group">
<label for="ShipPostalCode" class="control-label col-md-2">Ship Postal Code: </label>
<div class="col-md-5">
<InputText id="ShipPostalCode" class="form-control" @bind-Value="Item.ShipPostalCode" />
</div>
</div>
<div class="form-group">
<label for="ShipRegion" class="control-label col-md-2">Ship Region: </label>
<div class="col-md-5">
<InputText id="ShipRegion" class="form-control" @bind-Value="Item.ShipRegion" />
</div>
</div>
<div class="form-group">
<label for="ShipCountry" class="control-label col-md-2">Ship Country: </label>
<div class="col-md-5">
<InputText id="ShipCountry" class="form-control" @bind-Value="Item.ShipCountry" />
</div>
</div>
<div class="form-group">
<label for="Freight" class="control-label col-md-2">Freight: </label>
<div class="col-md-5">
<input id="Freight" name="Freight" class="form-control" @bind="Item.Freight" />
</div>
</div>
<div class="form-group">
<div class="col-md-5">
<button type="submit" class="btn btn-primary btn-md">@Strings.Save</button>
<button type="button" class="btn btn-primary btn-md" @onclick="BackButtonClicked">@Strings.Back</button>
</div>
</div>
</div>
</EditForm>
Note: The Blazor component must be to inherited from the GridUpdateComponentBase class.
If you want to use a drop-down list for a field you have to define it as it was for auto-generated forms.
You can configure a direct route to an specific CRUD form. The first step is to roure alternative routes as follows:
@page "/crud"
@page "/crud/{OrderId}/{Mode}"
Then you have to create and initialize the following parameters:
GridMode for the type of CRUD formobject[] for the primary keys of the row to be shown on the formThis is an example of these parameters initialization:
@code
{
...
private object[] _keys;
private GridMode _mode;
...
protected override async Task OnParametersSetAsync()
{
var locale = CultureInfo.CurrentCulture;
SharedResource.Culture = locale;
var query = new QueryDictionary<StringValues>();
Action<IGridColumnCollection<Order>> columns = c => ColumnCollections.OrderColumnsWithCrud(c,
customerService.GetAllCustomers, employeeService.GetAllEmployees, shipperService.GetAllShippers);
var client = new GridClient<Order>(q => orderService.GetOrdersGridRows(columns, q),
query, false, "ordersGrid", columns, locale)
.Sortable()
.Filterable()
.SetStriped(true)
.Crud(true, orderService)
.WithMultipleFilters()
.WithGridItemsCount();
_grid = client.Grid;
if (!string.IsNullOrWhiteSpace(OrderId))
{
int orderId;
bool result = int.TryParse(OrderId, out orderId);
if (result)
{
if (Mode.ToLower() == "create")
{
_keys = new object[] { orderId };
_mode = GridMode.Create;
}
else if (Mode.ToLower() == "read")
{
_keys = new object[] { orderId };
_mode = GridMode.Read;
}
else if (Mode.ToLower() == "update")
{
_keys = new object[] { orderId };
_mode = GridMode.Update;
}
else if (Mode.ToLower() == "delete")
{
_keys = new object[] { orderId };
_mode = GridMode.Delete;
}
}
}
// Set new items to grid
_task = client.UpdateGrid();
await _task;
}
...
And finaly you have to pass the paramenters initialized before to the GridComponent
<GridComponent T="Order" Grid="@_grid" Mode="_mode" Keys="_keys"></GridComponent>
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