I have an MVC JSON controller method that I call from frontend. It looks like this:
public JsonResult FacetedSearch(string searchString, List<KeyValuePair<string,string>> facets)
I'm calling it via jQuery ajax at the frontend, I'm serializing the data in the following manner:
JSON.stringify({searchString: "the matrix", facets: [{Key: "TypeName", Value: "Feature Film"}, {Key:"TypeName", Value:"Series"}]}
When I debug through my application code, I see that searchString gets passed successfully over to the MVC method, but the variable facets gives me a list of 2 KeyValuePairs with null Key and Value.
I've looked at my serialization and it seems valid but for whatever reason it isn't going over to my application correctly. What gives?
Rather than expect two objects in your signature, it would make more sense to expect a single object that contains both of your parameters. This would be something like the following.
public JsonResult FacetedSearch(RequestObject requestObject)
{ }
public class RequestObject
{
public string searchString { get; set; }
public List<KeyValuePair<string,string>> facets { get; set; }
}
This way, when you send your JSON object, the signature is an object with two properties, just like the object that you are sending.
Per Is there a serializable generic Key/Value pair class in .NET?
I found out why it's not serializing it. Apparently it's unserializable.
Related
I really cant wrap my head around this i have a List of this class
public class StandardText
{
public string Id { get; set; }
public string Value { get; set; }
}
I then want to use it in javascript where i pass down a model to a partialView. The problem is that i dont seem to be able to use it. i tried to JSON.parse() the list in the javascript but it will then try to JSON.parse() something like " System.Collections.Generic.List`1" so it is not trying to actually parse the values of the object. i also tried to JsonConvert before i send it down but i am failing on how to porperly convert it.
this is where i create the model and then send down the partialView
public async Task<ActionResult> _confirmText(TextViewModel model)
{
model.StandardText = await GetStandardText();
return PartialView(model);
}
Then in that partialView i simply want to pass it to my frontend via a global scope(i know bad)
var text = '#Model.StandardText';
window.addElementToModal(element, text);
And then the addElementToModal
(window as any).addElementToModel = ((root: HTMLElement, standardText: {[key: string]: string}) =>
{
init(root, standardText);
});
so i want to recieve it like {[key: string]: string} where am i going wrong?
Try this code:
const list = JSON.parse("#JsonConvert.SerializeObject(ViewBag.List)");
As a result you will get a plain JS array in list variable.
var text = '#Model.StandardText';
This is just going to ToString() the object. You could use JSON.NET For example to JSON Stringify it if that's your objective. e.g.
var text = '#Json.SerializeObject(Model.StandardText)';
I have an array filled with objects in JavaScript. I passed the entire array to an API. How can I access an object's properties, using C#?
Define C# model class that matches JavaScript objects, accept array of this object in your controller and you will have the objects to use within controller. JavaScript objects have to be sent in JSON format.
A. JSON in C# generally
Here are popular choices for interacting with json in .NET:
(.NET Core) System.Text.Json.JsonSerializer. Plase see How to serialize and deserialize JSON in .NET
JSON.NET with models. Please see Serializing and Deserializing JSON
JSON.NET's Linq to JSON. Please see LINQtoJSON or Querying JSON with LINQ
B ASP.NET example
Check out Examine the PostTodoItem create method in Tutorial: Create a web API with ASP.NET Core.
I shows you how to consume a json payloads.
Json
{
"name":"walk dog",
"isComplete":true
}
Model
namespace TodoApi.Models
{
public class TodoItem
{
public long Id { get; set; }
public string Name { get; set; }
public bool IsComplete { get; set; }
}
}
Controller action
// POST: api/TodoItems
[HttpPost]
public async Task<ActionResult<TodoItem>> PostTodoItem(TodoItem todoItem)
{
_context.TodoItems.Add(todoItem);
await _context.SaveChangesAsync();
//return CreatedAtAction("GetTodoItem", new { id = todoItem.Id }, todoItem);
return CreatedAtAction(nameof(GetTodoItem), new { id = todoItem.Id }, todoItem);
}
I'm implementing the "Save Draft" functionality on my dynamically generated page and trying to make it as generic as possible. All my controllers and pages should support it and that's why I thought about creating a SaveDraft() POST action in my base controller which will receive a serialized form as a string which can be directly saved into the database and deserialized to a view model later in the specific get action using specific view model
[HttpPost]
public ActionResult SaveDraft(string jsonData, long id)
My first idea was to create the generic base controller and pass the view model type to it but the problem is that some controllers have multiple differently named POST actions and using different view model types, I cant change it now.
Some view models are complex and looking like
public class CollateralsDataModel
{
//...
public List<Applicant> Applicants { get; set; }
}
public class Applicant
{
public long ApplicantId { get; set; }
public IList<RealEstateSecurityCollateralsDTO> RealEstateSecurityCollaterals { get; set; }
public IList<AdditionalCollateralDTO> AdditionalCollaterals { get; set; }
}
public class RealEstateSecurityCollateralsDTO
{
[Required]
[Display(ResourceType = typeof(CollateralsData), Name = nameof(CollateralsData.RealEstateSecurityType))]
public int? RealEstateSecurityTypeId { get; set; }
//...
}
The input names on the form are looking like
"Applicants[0].MortgageApplicantId": "11595",
"Applicants[0].RealEstateSecurityCollaterals[0].Id": "17",
"Applicants[1].MortgageApplicantId": "11596",
"Applicants[1].RealEstateSecurityCollaterals.Index": "0",
"Applicants[1].AdditionalCollaterals[0].Id": "138",
"Applicants[1].AdditionalCollaterals[0].AdditionalCollateralTypeId": "4",
My question is - how can I serialize them to the string so I can deserialize it later?
I tried using different combinations of
$('.draft-data-form').serializeArray()
$('.draft-data-form').serialize()
JSON.stringify($('.draft-data-form').serializeArray());
but in my Action I get the flat JSON structure and I can't deserialize it
var obj = JsonConvert.DeserializeObject<CollateralsDataModel>(jsonData);
Cannot deserialize the current JSON array (e.g. [1,2,3]) into type '...CollateralsDataModel' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly.
To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array.
I've also tried to deserialize it as a list but then I get the List of 115 entries
var obj = JsonConvert.DeserializeObject<List<CollateralsDataModel>>(jsonData);
So my question is - how can I serialize them to the string so I can deserialize it later?
You do not want to serialize/deserialize a List. Only a single instance of the model.
I would guess that the error is in instantiating the list within the model. I know that the DataContractSerializer has an issue where if the List is not instantiated to an empty list when the model is constructed then the deserialization is unable to add to it.
Not sure if this is the same problem you are facing but could be worth a try.
eg. use:
public List<Applicant> Applicants { get; set; } = new List<Applicant>();
I'm trying make a jquery.ajax call to the following controller action:
public ActionResult Handler(SemanticPart[] semanticParts, string first, string last)
I have the following data JSON object with the corresponding server side model having public { get; set; } properties:
var data = {
semanticParts: [{ hasLabel: "label", hasType: "type", hasIndex : 0 }],
first: "first",
last : "last"
};
The problem is jQuery.param seems to have no serialization option for the default MVC model binder.
decodeURIComponent($.param(data)) produces:
"semanticParts[0][hasLabel]=label&semanticParts[0][hasType]=type&semanticParts[0][hasIndex]=0&first=first&last=last"
while setting the traditional flag like so decodeURIComponent($.param(data, true)) produces:
"semanticParts=[object+Object]&first=first&last=last"
MVC's default model binder for complex arrays needs the following to bind correctly (tested in Fiddler Composer):
"semanticParts[0].hasLabel=label&semanticParts[0].hasType=type&semanticParts[0].hasIndex=0&first=first&last=last"
Which simply used: array[0].property= instead of array[0][property]=
I understand there's no universal specification for param strings agreed-upon by all web frameworks but why jQuery.param with traditional flag set true returns a [object+Object] is beyond me... that is absolutely useless in any framework.
It there any way to patch this?
Perhaps a regex to replace the pattern [#][text] with [#].text? (actually the encoded version of this is more relevant)
You should implement a model to hold this parameters:
public class SemanticPartViewModel
{
public List<SemanticPart> semanticParts { get; set;}
public string first { get; set; }
public string last { get; set;}
}
And change the controller to receive this as parameter
public ActionResult Handler(SemanticPartViewModel semanticParts)
{
/*Do stuff*/
}
You should use JSON.stringify(mydata) as well to create the data for the $.ajax call
This way the default modelbinder will take care about the rest.
I am getting this long error when i accpet the parameter as dynamic on my server side action method in mvc 4.
{"Message":"An error has
occurred.","ExceptionMessage":"'Newtonsoft.Json.Linq.JObject' does not
contain a definition for
'TournamentId'","ExceptionType":"Microsoft.CSharp.RuntimeBinder.RuntimeBinderException","StackTrace":"
at CallSite.Target(Closure , CallSite , Object )\r\n at
System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite
site, T0 arg0)\r\n at
ManagerDeTorneos.Web.Controllers.TournamentDateController.Create(Object
data) in
F:\Prince\Projects\Juan\trunk\ManagerDeTorneos.Web\Controllers\TournamentDateController.cs:line
133\r\n at lambda_method(Closure , Object , Object[] )\r\n at
System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c_DisplayClass13.b_c(Object
instance, Object[] methodParameters)\r\n at
System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object
instance, Object[] arguments)\r\n at
System.Threading.Tasks.TaskHelpers.RunSynchronously[TResult](Func`1
func, CancellationToken cancellationToken)"}
[HttpPost]
public HttpResponseMessage AddMatch(dynamic data)
{
int tournamentDateId = (int)data.TournamentDateId.Value;
var tournamentDate = Catalog.TournamentDateRepository.GetById(tournamentDateId);
if (tournamentDate == null)
{
throw ExceptionHelper.NotFound("Fecha no encontrada!");
}
In The above method data Contains tournamentId as sent from ajax call as JSON.Stringify({'TournamentId':'5'}).
Can anybody tell me what is the cause of error. I even replaced the dll of Newtonsoft.Json as well
You are right dan but i fixed my issue by removing that dll from GAC. May be in GAC it was using old assembly
The error is caused by the fact that you typed your parameter as dynamic, which means that the model binder doesn't know what to make it. It's the same as if you were to declare it as an object. Since you are providing JSON, it serializes the object as a Json.Net JObject. Just because you define it as a dynamic doesn't mean that it's going to magically take whatever shape you need it to.
Change it to a concrete type - something that matches the structure of the provided JSON:
public class TournamentInfo
{
public int TournamentId { get; set; }
}
[HttpPost]
public HttpResponseMessage AddMatch(TournamentInfo data)
{
int tournamentDateId = data.TournamentId;
var tournamentDate = Catalog.TournamentDateRepository.GetById(tournamentDateId);
if (tournamentDate == null)
{
throw ExceptionHelper.NotFound("Fecha no encontrada!");
}
This way, the binder knows what it's supposed to turn the JSON into, and since TournamentInfo matches the structure of the JSON, it won't have any trouble serializing it.
Don't misuse dynamic. It was not introduced into C# so developers could stop defining classes.