/// <summary>
/// Invokes the select method and gets the result. Also handles auto paging and sorting when required.
/// </summary>
/// <param name="arguments">The DataSourceSelectArguments for the select operation.
/// When applicable, this method sets the TotalRowCount out parameter in the arguments.
/// </param>
/// <returns>The return value from the select method.</returns>
protected virtual object GetSelectMethodResult(DataSourceSelectArguments arguments)
{
if (SelectMethod.Length == 0)
{
throw new InvalidOperationException(SR.GetString(SR.ModelDataSourceView_SelectNotSupported));
}
DataSourceSelectResultProcessingOptions options = null;
ModelDataSourceMethod method = EvaluateSelectMethodParameters(arguments, out options);
ModelDataMethodResult result = InvokeMethod(method);
return(ProcessSelectMethodResult(arguments, options, result));
}
/// <summary>
/// Evaluates the select method parameters and also determines the options for processing select result like auto paging and sorting behavior.
/// </summary>
/// <param name="arguments">The DataSourceSelectArguments for the select operation.</param>
/// <param name="selectResultProcessingOptions">The <see cref="System.Web.UI.WebControls.DataSourceSelectResultProcessingOptions"/> to use
/// for processing the select result once select operation is complete. These options are determined in this method and later used
/// by the method <see cref="System.Web.UI.WebControls.ModelDataSourceView.ProcessSelectMethodResult"/>.
/// </param>
/// <returns>A <see cref="System.Web.UI.WebControls.ModelDataSourceMethod"/> with the information required to invoke the select method.</returns>
protected virtual ModelDataSourceMethod EvaluateSelectMethodParameters(DataSourceSelectArguments arguments, out DataSourceSelectResultProcessingOptions selectResultProcessingOptions)
{
ModelDataSourceMethod method;
IOrderedDictionary mergedParameters = MergeSelectParameters(arguments);
// Resolve the method
method = FindMethod(SelectMethod);
Type selectMethodReturnType = method.MethodInfo.ReturnType;
Type modelType = ModelType;
if (modelType == null)
{
//When ModelType is not specified but SelectMethod returns IQueryable<T>, we treat T as model type for auto paging and sorting.
//If the return type is something like CustomType<U,T> : IQueryable<T>, we should use T for paging and sorting, hence
//we walk over the return type's generic arguments for a proper match.
foreach (Type typeParameter in selectMethodReturnType.GetGenericArguments())
{
if (typeof(IQueryable <>).MakeGenericType(typeParameter).IsAssignableFrom(selectMethodReturnType))
{
modelType = typeParameter;
}
}
}
Type queryableModelType = (modelType != null) ? typeof(IQueryable <>).MakeGenericType(modelType) : null;
//We do auto paging or auto sorting when the select method is returning an IQueryable and does not have parameters for paging or sorting.
bool isReturningQueryable = queryableModelType != null && queryableModelType.IsAssignableFrom(selectMethodReturnType);
bool autoPage = false;
bool autoSort = false;
if (arguments.StartRowIndex >= 0 && arguments.MaximumRows > 0)
{
autoPage = IsAutoPagingRequired(method.MethodInfo, isReturningQueryable);
}
if (!String.IsNullOrEmpty(arguments.SortExpression))
{
autoSort = IsAutoSortingRequired(method.MethodInfo, isReturningQueryable);
}
selectResultProcessingOptions = new DataSourceSelectResultProcessingOptions()
{
ModelType = modelType, AutoPage = autoPage, AutoSort = autoSort
};
EvaluateMethodParameters(DataSourceOperation.Select, method, mergedParameters);
return(method);
}
/// <summary>
/// This method performs operations on the select method result like auto paging and sorting if applicable.
/// </summary>
/// <param name="arguments">The DataSourceSelectArguments for the select operation.</param>
/// <param name="selectResultProcessingOptions">The <see cref="System.Web.UI.WebControls.DataSourceSelectResultProcessingOptions"/> to use for processing the select result.
/// These options are determined in an earlier call to <see cref="System.Web.UI.WebControls.ModelDataSourceView.EvaluateSelectMethodParameters"/>.
/// </param>
/// <param name="result">The result after operations like auto paging/sorting are done.</param>
/// <returns></returns>
protected virtual object ProcessSelectMethodResult(DataSourceSelectArguments arguments, DataSourceSelectResultProcessingOptions selectResultProcessingOptions, ModelDataMethodResult result) {
// If the return value is null, there is no more processing to be done
if (result.ReturnValue == null) {
return null;
}
bool autoPage = selectResultProcessingOptions.AutoPage;
bool autoSort = selectResultProcessingOptions.AutoSort;
Type modelType = selectResultProcessingOptions.ModelType;
string sortExpression = arguments.SortExpression;
if (autoPage) {
MethodInfo countHelperMethod = typeof(QueryableHelpers).GetMethod("CountHelper").MakeGenericMethod(modelType);
arguments.TotalRowCount = (int)countHelperMethod.Invoke(null, new object[] { result.ReturnValue });
//Bug 180907: We would like to auto sort on DataKeyName when paging is enabled and result is not already sorted by user to overcome a limitation in EF.
MethodInfo isOrderingMethodFoundMethod = typeof(QueryableHelpers).GetMethod("IsOrderingMethodFound").MakeGenericMethod(modelType);
bool isOrderingMethodFound = (bool)isOrderingMethodFoundMethod.Invoke(null, new object[] { result.ReturnValue });
if (!isOrderingMethodFound) {
if (String.IsNullOrEmpty(sortExpression) && !String.IsNullOrEmpty(DataKeyName)) {
autoSort = true;
selectResultProcessingOptions.AutoSort = true;
sortExpression = DataKeyName;
}
}
}
else if (arguments.StartRowIndex >= 0 && arguments.MaximumRows > 0) {
//When paging is handled by developer, we need to set the TotalRowCount parameter from the select method out parameter.
arguments.TotalRowCount = (int)result.OutputParameters[TotalRowCountParameterName];
}
if (autoPage || autoSort) {
MethodInfo sortPageHelperMethod = typeof(QueryableHelpers).GetMethod("SortandPageHelper").MakeGenericMethod(modelType);
object returnValue = sortPageHelperMethod.Invoke(null, new object[] { result.ReturnValue,
autoPage ? (int?)arguments.StartRowIndex : null,
autoPage ? (int?)arguments.MaximumRows : null,
autoSort ? sortExpression : null });
return returnValue;
}
return result.ReturnValue;
}
private ModelDataSourceMethod EvaluateSelectMethodParameters(DataSourceSelectArguments arguments, ModelDataSourceMethod method, bool isAsyncSelect, out DataSourceSelectResultProcessingOptions selectResultProcessingOptions) {
IOrderedDictionary mergedParameters = MergeSelectParameters(arguments);
// Resolve the method
method = method ?? FindMethod(SelectMethod);
Type selectMethodReturnType = method.MethodInfo.ReturnType;
if (isAsyncSelect) {
selectMethodReturnType = ExtractAsyncSelectReturnType(selectMethodReturnType);
}
Type modelType = ModelType;
if (modelType == null) {
//When ModelType is not specified but SelectMethod returns IQueryable<T>, we treat T as model type for auto paging and sorting.
//If the return type is something like CustomType<U,T> : IQueryable<T>, we should use T for paging and sorting, hence
//we walk over the return type's generic arguments for a proper match.
foreach (Type typeParameter in selectMethodReturnType.GetGenericArguments()) {
if (typeof(IQueryable<>).MakeGenericType(typeParameter).IsAssignableFrom(selectMethodReturnType)) {
modelType = typeParameter;
}
}
}
Type queryableModelType = (modelType != null) ? typeof(IQueryable<>).MakeGenericType(modelType) : null;
//We do auto paging or auto sorting when the select method is returning an IQueryable and does not have parameters for paging or sorting.
bool isReturningQueryable = queryableModelType != null && queryableModelType.IsAssignableFrom(selectMethodReturnType);
if (isAsyncSelect && isReturningQueryable) {
// async select method does not support returning IQueryable<>.
throw new InvalidOperationException(SR.GetString(SR.ModelDataSourceView_InvalidAsyncSelectReturnType, modelType));
}
bool autoPage = false;
bool autoSort = false;
if (arguments.StartRowIndex >= 0 && arguments.MaximumRows > 0) {
autoPage = IsAutoPagingRequired(method.MethodInfo, isReturningQueryable, isAsyncSelect);
if (isAsyncSelect) {
Debug.Assert(!autoPage, "auto-paging should not be true when using async select method");
// custom paging is not supported if the return type is not SelectResult
if (typeof(SelectResult) != selectMethodReturnType) {
throw new InvalidOperationException(SR.GetString(SR.ModelDataSourceView_MustUseSelectResultAsReturnType));
}
}
}
if (!String.IsNullOrEmpty(arguments.SortExpression)) {
autoSort = IsAutoSortingRequired(method.MethodInfo, isReturningQueryable);
}
selectResultProcessingOptions = new DataSourceSelectResultProcessingOptions() { ModelType = modelType, AutoPage = autoPage, AutoSort = autoSort };
EvaluateMethodParameters(DataSourceOperation.Select, method, mergedParameters);
return method;
}
/// <summary>
/// Evaluates the select method parameters and also determines the options for processing select result like auto paging and sorting behavior.
/// </summary>
/// <param name="arguments">The DataSourceSelectArguments for the select operation.</param>
/// <param name="selectResultProcessingOptions">The <see cref="System.Web.UI.WebControls.DataSourceSelectResultProcessingOptions"/> to use
/// for processing the select result once select operation is complete. These options are determined in this method and later used
/// by the method <see cref="System.Web.UI.WebControls.ModelDataSourceView.ProcessSelectMethodResult"/>.
/// </param>
/// <returns>A <see cref="System.Web.UI.WebControls.ModelDataSourceMethod"/> with the information required to invoke the select method.</returns>
protected virtual ModelDataSourceMethod EvaluateSelectMethodParameters(DataSourceSelectArguments arguments, out DataSourceSelectResultProcessingOptions selectResultProcessingOptions) {
return EvaluateSelectMethodParameters(arguments, null/*method*/, false /*isAsyncSelect*/, out selectResultProcessingOptions);
}
/// <summary>
/// This method performs operations on the select method result like auto paging and sorting if applicable.
/// </summary>
/// <param name="arguments">The DataSourceSelectArguments for the select operation.</param>
/// <param name="selectResultProcessingOptions">The <see cref="System.Web.UI.WebControls.DataSourceSelectResultProcessingOptions"/> to use for processing the select result.
/// These options are determined in an earlier call to <see cref="System.Web.UI.WebControls.ModelDataSourceView.EvaluateSelectMethodParameters"/>.
/// </param>
/// <param name="result">The result after operations like auto paging/sorting are done.</param>
/// <returns></returns>
protected virtual object ProcessSelectMethodResult(DataSourceSelectArguments arguments, DataSourceSelectResultProcessingOptions selectResultProcessingOptions, ModelDataMethodResult result)
{
// If the return value is null, there is no more processing to be done
if (result.ReturnValue == null)
{
return(null);
}
bool autoPage = selectResultProcessingOptions.AutoPage;
bool autoSort = selectResultProcessingOptions.AutoSort;
Type modelType = selectResultProcessingOptions.ModelType;
string sortExpression = arguments.SortExpression;
if (autoPage)
{
MethodInfo countHelperMethod = typeof(QueryableHelpers).GetMethod("CountHelper").MakeGenericMethod(modelType);
arguments.TotalRowCount = (int)countHelperMethod.Invoke(null, new object[] { result.ReturnValue });
//Bug 180907: We would like to auto sort on DataKeyName when paging is enabled and result is not already sorted by user to overcome a limitation in EF.
MethodInfo isOrderingMethodFoundMethod = typeof(QueryableHelpers).GetMethod("IsOrderingMethodFound").MakeGenericMethod(modelType);
bool isOrderingMethodFound = (bool)isOrderingMethodFoundMethod.Invoke(null, new object[] { result.ReturnValue });
if (!isOrderingMethodFound)
{
if (String.IsNullOrEmpty(sortExpression) && !String.IsNullOrEmpty(DataKeyName))
{
autoSort = true;
selectResultProcessingOptions.AutoSort = true;
sortExpression = DataKeyName;
}
}
}
else if (arguments.StartRowIndex >= 0 && arguments.MaximumRows > 0)
{
//When paging is handled by developer, we need to set the TotalRowCount parameter from the select method out parameter.
arguments.TotalRowCount = (int)result.OutputParameters[TotalRowCountParameterName];
}
if (autoPage || autoSort)
{
MethodInfo sortPageHelperMethod = typeof(QueryableHelpers).GetMethod("SortandPageHelper").MakeGenericMethod(modelType);
object returnValue = sortPageHelperMethod.Invoke(null, new object[] { result.ReturnValue,
autoPage ? (int?)arguments.StartRowIndex : null,
autoPage ? (int?)arguments.MaximumRows : null,
autoSort ? sortExpression : null });
return(returnValue);
}
return(result.ReturnValue);
}
/// <summary>
/// Evaluates the select method parameters and also determines the options for processing select result like auto paging and sorting behavior.
/// </summary>
/// <param name="arguments">The DataSourceSelectArguments for the select operation.</param>
/// <param name="selectResultProcessingOptions">The <see cref="System.Web.UI.WebControls.DataSourceSelectResultProcessingOptions"/> to use
/// for processing the select result once select operation is complete. These options are determined in this method and later used
/// by the method <see cref="System.Web.UI.WebControls.ModelDataSourceView.ProcessSelectMethodResult"/>.
/// </param>
/// <returns>A <see cref="System.Web.UI.WebControls.ModelDataSourceMethod"/> with the information required to invoke the select method.</returns>
protected virtual ModelDataSourceMethod EvaluateSelectMethodParameters(DataSourceSelectArguments arguments, out DataSourceSelectResultProcessingOptions selectResultProcessingOptions) {
ModelDataSourceMethod method;
IOrderedDictionary mergedParameters = MergeSelectParameters(arguments);
// Resolve the method
method = FindMethod(SelectMethod);
Type selectMethodReturnType = method.MethodInfo.ReturnType;
Type modelType = ModelType;
if (modelType == null) {
//When ModelType is not specified but SelectMethod returns IQueryable<T>, we treat T as model type for auto paging and sorting.
//If the return type is something like CustomType<U,T> : IQueryable<T>, we should use T for paging and sorting, hence
//we walk over the return type's generic arguments for a proper match.
foreach (Type typeParameter in selectMethodReturnType.GetGenericArguments()) {
if (typeof(IQueryable<>).MakeGenericType(typeParameter).IsAssignableFrom(selectMethodReturnType)) {
modelType = typeParameter;
}
}
}
Type queryableModelType = (modelType != null) ? typeof(IQueryable<>).MakeGenericType(modelType) : null;
//We do auto paging or auto sorting when the select method is returning an IQueryable and does not have parameters for paging or sorting.
bool isReturningQueryable = queryableModelType != null && queryableModelType.IsAssignableFrom(selectMethodReturnType);
bool autoPage = false;
bool autoSort = false;
if (arguments.StartRowIndex >= 0 && arguments.MaximumRows > 0) {
autoPage = IsAutoPagingRequired(method.MethodInfo, isReturningQueryable);
}
if (!String.IsNullOrEmpty(arguments.SortExpression)) {
autoSort = IsAutoSortingRequired(method.MethodInfo, isReturningQueryable);
}
selectResultProcessingOptions = new DataSourceSelectResultProcessingOptions() { ModelType = modelType, AutoPage = autoPage, AutoSort = autoSort };
EvaluateMethodParameters(DataSourceOperation.Select, method, mergedParameters);
return method;
}
