我正在尝试创建 Web API 模型绑定(bind)器，它将绑定(bind)由 javascript 框架的网格组件发送的 URL 参数。 Grid 发送 URL 参数，指示标准页面、pageSize 和 JSON 格式的排序器、过滤器和分组器。 URL 字符串如下所示:
http://localhost/api/inventory?page=1&start=0&limit=10sort=[{"property":"partName","direction":"desc"},{"property":"partStatus","direction":"asc"}]&group=[{"property":"count","direction":"asc"}]
所讨论的模型是 Inventory，它具有简单的 Count (int) 属性和一个引用 Part (Part) 属性(后者又具有 Name、Status)。 View 模型/dto 被展平(InventoryViewModel .Count、.PartName、.PartStatus 等) 我用 Dynamic Expression Api然后查询域模型，将结果映射到 View 模型并将其作为 JSON 发送回。 在模型绑定(bind)期间，我需要通过检查正在使用的模型和 View 模型来构建表达式。
为了保持模型绑定(bind)器可重用，我如何传递/指定正在使用的模型和 View 模型类型？ 我需要这个来构建有效的排序、过滤和分组 expsessions 注意:我不想将这些作为网格 url 参数的一部分传递!
我的一个想法是使 StoreRequest 通用(例如 StoreRequest)，但我不确定模型绑定(bind)器是否或如何工作。
示例 API Controller
// 1. model binder is used to transform URL params into StoreRequest. Is there a way to "pass" types of model & view model to it?
public HttpResponseMessage Get(StoreRequest storeRequest)
{
int total;
// 2. domain entites are then queried using StoreRequest properties and Dynamic Expression API (e.g. "Order By Part.Name DESC, Part.Status ASC")
var inventoryItems = _inventoryService.GetAll(storeRequest.Page, out total, storeRequest.PageSize, storeRequest.SortExpression);
// 3. model is then mapped to view model/dto
var inventoryDto = _mapper.MapToDto(inventoryItems);
// 4. response is created and view model is wrapped into grid friendly JSON
var response = Request.CreateResponse(HttpStatusCode.OK, inventoryDto.ToGridResult(total));
response.Content.Headers.Expires = DateTimeOffset.UtcNow.AddMinutes(5);
return response;
}
StoreRequestModelBinder
public class StoreRequestModelBinder : IModelBinder
{
private static readonly ILog Logger = LogManager.GetCurrentClassLogger();
public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
{
Logger.Debug(m => m("Testing model binder for type: {0}", bindingContext.ModelType));
if (bindingContext.ModelType != typeof(StoreRequest))
{
return false;
}
var storeRequest = new StoreRequest();
// ----------------------------------------------------------------
int page;
if (TryGetValue(bindingContext, StoreRequest.PageParameter, out page))
{
storeRequest.Page = page;
}
// ----------------------------------------------------------------
int pageSize;
if (TryGetValue(bindingContext, StoreRequest.PageSizeParameter, out pageSize))
{
storeRequest.PageSize = pageSize;
}
// ----------------------------------------------------------------
string sort;
if (TryGetValue(bindingContext, StoreRequest.SortParameter, out sort))
{
try
{
storeRequest.Sorters = JsonConvert.DeserializeObject<List<Sorter>>(sort);
// TODO: build sort expression using model and viewModel types
}
catch(Exception e)
{
Logger.Warn(m=>m("Unable to parse sort parameter: \"{0}\"", sort), e);
}
}
// ----------------------------------------------------------------
bindingContext.Model = storeRequest;
return true;
}
private bool TryGetValue<T>(ModelBindingContext bindingContext, string key, out T result)
{
var valueProviderResult = bindingContext.ValueProvider.GetValue(key);
if (valueProviderResult == null)
{
result = default(T);
return false;
}
result = (T)valueProviderResult.ConvertTo(typeof(T));
return true;
}
}
请您参考如下方法:
只需更改您的 Controller 签名即可
public HttpResponseMessage Get([ModelBinder(typeof(StoreRequestModelBinder)]StoreRequest storeRequest)
问候
