Can I create a TypeScript type and use that when AJAX returns JSON data?

Question

I have the following C# class:

public class JsonBackup {     public int Added { set; get; }     public int DEVCount { set; get; }     public int DS1Count { set; get; }     public IList<ViewEvent> Events { get; set; }     public IEnumerable<string> Errors { set; get; }     public int Rejected { set; get; }     public bool Success { set; get; }     public int Updated { set; get; } } 

and this code to return JSON data to my browser:

return Json(new JsonBackup {     Added = added,     DEVCount = devCount,     DS1Count = ds1Count,     Events = t.Events,     Rejected = rejected,     Success = true,     Updated = updated }); 

The data is returned here:

 $.ajax("/Backup/Data/Backup",     {         cache: false,         dataType: 'json',         type: 'POST'     })  .done(function (data: ) {      console.log(data);      backupDone(data, ajaxElapsed);  }); 

and used in other places and also here:

   $.each(data.Events, function (i, item) {         $("#stats-list li:eq("+(4+i)+")").after('<li>' + item.Description + ' : ' + item.Elapsed + ' ms</li>');     }); 

Is it possible for me to create a TypeScript type and assign data to that type so I could for example get intellisense when selecting such things as

data.Added or data.DEVCount etc? 

Answer 1

Simplest way to achieve that is to create interface for IJsonBackup and when you receive json just cast it to IJsonBackup

interface IViewEvent { }  interface IJsonBackup {     Added : number;     DEVCount : number;     DS1Count : number;     Events : IViewEvent[];     Errors : string[];     Rejected : number;     Success : bool;     Updated : number; } 

In your class definition:

backupDone(data: IJsonBackup, ajaxElapsed: any) { }  $.ajax("/Backup/Data/Backup",     {         cache: false,         dataType: 'json',         type: 'POST'     })     .done(function (data: any) {         console.log(data);         backupDone(<IJsonBackup>data, ajaxElapsed);     });