Quick_start.md

Blazor WASM with OData back-end

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. Add a reference to GridBlazor, GridBlazor.Pages, GridShared and GridShared.Utility in the _Imports.razor file of the client project's root folder

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

2. Create a razor page on the client project to render the grid using the GridOdataClient object. The page file must have a .razor extension. An example of razor page is:

       @page "/gridsample"
       @using GridShared
       @using GridShared.Utility
       @using Microsoft.Extensions.Primitives
       @inject NavigationManager NavigationManager
       @inject HttpClient HttpClient
   
       @if (_task.IsCompleted)
       {
           <GridComponent T="Order" Grid="@_grid"></GridComponent>
       }
       else
       {
           <p><em>Loading...</em></p>
       }
   
       @code
       {
           private CGrid<Order> _grid;
           private Task _task;
   
           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);
           };
   
           protected override async Task OnParametersSetAsync()
           {
               string url = NavigationManager.GetBaseUri() + "odata/orders";
               var query = new QueryDictionary<StringValues>();
   
               var client = new GridODataClient<Order>(HttpClient, url, query, false, "ordersGrid", columns, 10);
               _grid = client.Grid;
   
               // Set new items to grid
               _task = client.UpdateGrid();
               await _task;
           }
       }

3. Create an ODataController action in the server project. An example of this type of controller action is:

       public class OrdersController : ODataController
       {
           private readonly NorthwindDbContext _context;
   
           public OrdersController(NorthwindDbContext context)
           {
              _context = context;
           }
   
           ...
   
           [EnableQuery]
           public IActionResult Get()
           {
               var repository = new OrdersRepository(_context);
               var orders = repository.GetAll();
               return Ok(orders);
           }
       }

Notes:

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

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

      var client = new GridODataClient<Order>(HttpClient, url, query, false, "ordersGrid", columns, 10, locale)
          .SetRowCssClasses(item => item.Customer.IsVip ? "success" : string.Empty)
          .Sortable()
          .Filterable()
          .WithMultipleFilters();

• You must call the UpdateGrid method of the GridODataClient 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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