/// <summary>
/// Adds a Where clause to the given query for the specified property, and a list of operators that take no values.
/// If any of the specified operators are not valid, then adds validation errors and returns the same query.
/// </summary>
/// <typeparam name="TElement">The type of the element.</typeparam>
/// <typeparam name="TValue">The type of the values.</typeparam>
/// <param name="qry">The query to add the Where clause to.</param>
/// <param name="propName">Property display name.</param>
/// <param name="prop">Expression for the property accessor.</param>
/// <param name="operators">A list of operator names or aliases.</param>
/// <returns>The query with the Where clause added, or the same query if input is invalid.</returns>
protected virtual IQueryable <TElement> AddClause <TElement, TValue>(IQueryable <TElement> qry, string propName,
Expression <Func <TElement, TValue> > prop, ICollection <string> operators)
{
if (operators == null || operators.Count == 0)
{
return(qry); // assume no criteria, do nothing
}
var expressions = new List <Expression>();
foreach (string oper in operators)
{
Operator op = GetOperator(oper, typeof(TValue));
if (op == null)
{
currentErrors.AddValidationError(Messages.Operator_NotSupported, oper, GetPropertyName(propName, prop.Body));
}
else
{
expressions.Add(op.GetPredicate(prop).Body);
}
}
if (expressions.Count < operators.Count)
{
return(qry); // some operators are invalid
}
Expression agg = expressions.Aggregate((a, b) => Expression.Or(a, b));
return(qry.Where(Expression.Lambda <Func <TElement, bool> >(agg, prop.Parameters)));
}
/// <summary>
/// Adds model validation errors from the model state to the list of current errors.
/// </summary>
/// <param name="currentErrors">The list of current errors to add any model validation errors to.</param>
/// <param name="modelState">Model state that contains model validation errors.</param>
public static void AddModelErrors(this ErrorList currentErrors, ModelStateDictionary modelState)
{
foreach (var ms in modelState)
{
foreach (var err in ms.Value.Errors)
{
if (!string.IsNullOrEmpty(err.ErrorMessage))
{
currentErrors.AddValidationError(err.ErrorMessage);
}
else if (err.Exception != null)
{
currentErrors.AddValidationError(err.Exception.Message);
}
}
}
}
/// <summary>
/// Asynchronously validates if an object with the given primary key exists in the store, and reports an error if not.
/// </summary>
/// <typeparam name="T">The type of entity to validate.</typeparam>
/// <param name="ctx">The DbContext to use.</param>
/// <param name="errorList">The current error list to use for reporting errors.</param>
/// <param name="param">The name of the key input parameter(s) to use in the error.</param>
/// <param name="keys">The values of the primary key to validate.</param>
public static async Task ValidateKeyAsync <T>(this DbContext ctx, ErrorList errorList, string param, params object[] keys) where T : class
{
if (keys == null || keys.Length == 0 || keys.All(k => k == null))
{
return;
}
T entity = await ctx.Set <T>()?.FindAsync(keys);
if (entity == null)
{
string error = keys.Length > 1 ? Messages.InvalidForeignKeys : Messages.InvalidForeignKey;
errorList.AddValidationError(error, string.Join <object>(", ", keys), param, typeof(T).Name);
}
}
/// <summary>
/// Called before client calls are sent and after service responses are returned.
/// </summary>
/// <param name="operationName">The name of the operation.</param>
/// <param name="inputs">The objects passed to the method by the client.</param>
/// <returns>The correlation state that is returned as the correlationState parameter in <see cref="AfterCall(string, object[], object, object)"/>.
/// Return null if you do not intend to use correlation state.</returns>
public object BeforeCall(string operationName, object[] inputs)
{
InstanceContextServiceScope ctxScope = OperationContext.Current.InstanceContext.Extensions.Find <InstanceContextServiceScope>();
var svcProvider = ctxScope?.GetServiceScope(null)?.ServiceProvider;
ErrorList errors = svcProvider?.GetService <ErrorList>();
if (errors == null)
{
return(null);
}
foreach (object obj in inputs)
{
foreach (ValidationResult result in DataAnnotationValidator.GetValidationErrors(serviceProvider, obj))
{
errors.AddValidationError(result.ErrorMessage);
}
}
return(null);
}
