Quick_start.md

Blazor server-side

Quick start with GridBlazor

Index

Imagine that you have to retrieve a collection of model items in your project. For example if your model class is:

    public class Order
    {
        [Key]
        public int OrderID { get; set; }
        public string CustomerID { get; set; }
        public DateTime? OrderDate { get; set; }
        public virtual Customer Customer { get; set; }
        ...
    }

The steps to build a grid razor page using GridBlazor are:

1. Create a service with a method to get all items for the grid. An example of this type of service is:

       public class OrderService
       {
           ...
   
           public ItemsDTO<Order> GetOrdersGridRows(Action<IGridColumnCollection<Order>> columns,
                   QueryDictionary<StringValues> query)
           {
               var repository = new OrdersRepository(_context);
               var server = new GridCoreServer<Order>(repository.GetAll(), new QueryCollection(query), 
                   true, "ordersGrid", columns, 10);
           
               // return items to displays
               return server.ItemsToDisplay;
           }
       }

   Notes:

   • The method must have 2 parameters:

     • the first one is a lambda expression with the column definition of type Action<IGridColumnCollection>
     • the second one is a dictionary to pass query parameters such as grid-page. It must be ot type QueryDictionary

   • You can use multiple methods of the GridCoreServer object to configure a grid on the server. For example:

         var server = new GridCoreServer<Order>(repository.GetAll(), Request.Query, true, "ordersGrid", columns, 10)
             .Sortable()
             .Filterable()
             .WithMultipleFilters();

   • The method returns an object including the model rows to be shown on the grid and other information requirired for paging, etc. The object type returned by the action must be ItemsDTO.

   • You can use one of the following methods to get ItemsDTO object:

     • server.ItemsToDisplay returns the object using the standard ToList method of the IQueryable<T> object supplied by System.Linq package
     • await server.GetItemsToDisplayAsync(Func<IQueryable<T>, Task<IList<T>>> toListAsync) returns the object using a customtoListAsync method of the IQueryable<T> object. This method can be supplied by an ORM like EF Core. In this case we can call await server.GetItemsToDisplayAsync(async x => await x.ToListAsync())

2. You have to register the service in the Startup class:

       public void ConfigureServices(IServiceCollection services)
       {
           ...
   
           services.AddScoped<OrderService>();
           
           ...
       }

3. Add a reference to GridBlazor, GridBlazor.Pages, GridShared and GridShared.Utility in the _Imports.razor file of the root folder

       ...
       @using GridBlazor
       @using GridBlazor.Pages
       @using GridShared
       @using GridShared.Utility
       ...

4. Create a razor page to render the grid. The page file must have a .razor extension. An example of razor page is:

       @page "/gridsample"
       @using Microsoft.Extensions.Primitives
       @inject OrderService orderService
   
       @if (_task.IsCompleted)
       {
           <GridComponent T="Order" Grid="@_grid"></GridComponent>
       }
       else
       {
           <p><em>Loading...</em></p>
       }
   
       @code
       {
           private CGrid<Order> _grid;
           private Task _task;
   
           protected override async Task OnParametersSetAsync()
           {
               Action<IGridColumnCollection<Order>> columns = c =>
               {
                   c.Add(o => o.OrderID);
                   c.Add(o => o.OrderDate, "OrderCustomDate").Format("{0:yyyy-MM-dd}");
                   c.Add(o => o.Customer.CompanyName);
                   c.Add(o => o.Customer.IsVip);
               };
   
               var query = new QueryDictionary<StringValues>();
               query.Add("grid-page", "2");
   
               var client = new GridClient<Order>(q => orderService.GetOrdersGridRows(columns, q), query, false, "ordersGrid", columns);
               _grid = client.Grid;
   
               // Set new items to grid
               _task = client.UpdateGrid();
               await _task;
           }
       }

   Notes:

   • You must create a GridClient object in the OnParametersSetAsync of the razor page. This object contains a parameter of CGrid type called Grid.

   • You can use multiple methods of the GridClient object to configure a grid. For example:

         var client = new GridClient<Order>(q => orderService.GetOrdersGridRows(columns, q), query, false, "ordersGrid", columns)
             .SetRowCssClasses(item => item.Customer.IsVip ? "success" : string.Empty)
             .Sortable()
             .Filterable()
             .WithMultipleFilters();

   • The GridClient object used on the razor page and the GridCoreServer object on the service must have compatible settings.

   • You must call the UpdateGrid method of the GridClient object at the end of the OnParametersSetAsync of the razor page because it will request for the required rows to the server

   • If you need to update the component out of OnParametersSetAsync method you must use a reference to the component:

         <GridComponent @ref="Component" T="Order" Grid="@_grid"></GridComponent>

     and then call the UpdateGrid method:

         await Component.UpdateGrid();

   • The GridComponent tag must contain at least these 2 attributes:

     • T: type of the model items
     • Grid: grid object that has to be created in the OnParametersSetAsync method of the razor page

For more documentation about column options, please see: Custom columns.

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