问题背景
为了避免重复验证逻辑,我遵循将Server Side ModelState错误推送到我的View Model(MVVM KnockoutJS)的模式.
所以按照惯例我的属性名称在我的KO viewmodel匹配属性我的Api是暴露和期望,因此我可以使用一个小的Knockout插件我写的一个很容易地映射到另一个.
<validation-summary params="vm: $data,class: 'alert alert-error'"></validation-summary>
...
<div class="control-group" data-bind="errorCss: {'error': spend }">
<label class="control-label" for="spend">Spend</label>
<div class="controls">
<div class="input-prepend">
<span class="add-on">$</span>
<input type="text" data-bind="value: spend" id="spend" class="input-medium" placeholder="Spend USD" />
</div>
<validation-message params="bind: spend,class: 'text-error'"></validation-message>
</div>
</div>
问题
我的问题是,当JSON.Net串行化我发送的JSON和AJAX,当遇到异常时,它将它添加到ModelError类的ModelState和异常.
响应示例
{
"message": "The request is invalid.","modelState": {
"cmd.spend": [
"Error converting value \"ii\" to type 'System.Double'. Path 'spend',line 1,position 13.","'Spend' must be greater than '0'."
],"cmd.Title": [
"'Title' should not be empty."
]
}
}
问题由于这个消息并不能给出一个很好的UX：
Error converting value "ii" to type 'System.Double'. Path 'spend',position 13.
事实上,我无法将这个异常消息与我的验证消息分开,因为它们都在一个数组中.
我宁愿删除它,并在我的ValidationClass处理这个问题
我可以像这样手动删除它们,这是一个ActionFilter,所以我只有一次.
public class ValidateCommandAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
ModelStateDictionary modelState = actionContext.ModelState;
#if !DEBUG
for (int i = 0; i < modelState.Values.Count; i++)
{
ModelErrorCollection errors = modelState.ElementAt(i).Value.Errors;
for (int i2 = 0; i2 < errors.Count; i2++)
{
ModelError error = errors.ElementAt(i2);
if (error.Exception != null)
{
// TODO: Add Log4Net Here
errors.RemoveAt(i2);
}
}
}
#endif
if (!modelState.IsValid)
actionContext.Response = actionContext.Request.CreateErrorResponse(HttpStatusCode.BadRequest,modelState);
}
}
我知道JSON.Net是高度可配置的,想知道API中有没有哪里可以关闭它,还是抑制它？
解决方法
你可以设置一个
error handler.例如(从json.net docs),
List<string> errors = new List<string>();
List<DateTime> c = JsonConvert.DeserializeObject<List<DateTime>>(@"[
'2009-09-09T00:00:00Z','I am not a date and will error!',[
1
],'1977-02-20T00:00:00Z',null,'2000-12-01T00:00:00Z'
]",new JsonSerializerSettings
{
Error = delegate(object sender,ErrorEventArgs args)
{
errors.Add(args.ErrorContext.Error.Message);
args.ErrorContext.Handled = true;
},Converters = { new IsoDateTimeConverter() }
});
// 2009-09-09T00:00:00Z
// 1977-02-20T00:00:00Z
// 2000-12-01T00:00:00Z
// The string was not recognized as a valid DateTime. There is a unknown word starting at index 0.
// Unexpected token parsing date. Expected String,got StartArray.
// Cannot convert null value to System.DateTime.
