Generic Kendo MVC Grid Used with Different Models - asp.net-mvc

I am trying to use a Kendo Grid generically as a partial view. Kendo requires either a type defined or a datatable to instantiate the grid in a razor view
#(Html.Kendo().Grid<object>() or #(Html.Kendo().Grid(dataTable)
My issue is i want to use the Grid for whatever object, not a specific one.
#(Html.Kendo().Grid<object>()
.Name(Model.MetricName)
.Resizable(resizing => resizing.Columns(true))
.Reorderable(reorder => reorder.Columns(true))
.Sortable(sorting => sorting.Enabled(true))
.Pageable(pager => pager.PageSizes(new int[] { 10, 15, 20, 50 }))
.ColumnMenu()
.DataSource(dataSource => dataSource
.Ajax()
.Read(read => read.Action(Model.MetricName, "AdHocReport", new { metricId = Model.MetricId }))
)
)
by using Object i am able to dynamically load the data returned from the ajax .read method. However the issue is with dates. They are returned in JSON format.
Ive tried this method and I still get JSON string representation of the date
Kendo ASP.NET MVC helper Grid generic class
Is there a way to define the type of grid from a string representation of the type? So lets say i have a string property on the viewModel that is the type of the grid. How can i say Grid ?
ive tried using reflection to instantiate the type but i get the infamous "you are using a variable like a type"
This is driving me nuts... any and all help would be greatly appreciated

So i found the way to make this work and bind correctly and as mentioned above my mrmashal it has to do with using dataTables.
#(Html.Kendo().Grid(Model.GridTable)
here is the viewModel property
public DataTable GridTable { get; set; }
To make this dynamic i use reflection to define the dataTable based upon the properties of a the class i want to populate the grid with
Type elementType = Type.GetType(className, true);
var properties = elementType.GetProperties();
DataTable dataTable = new DataTable();
foreach (PropertyInfo info in properties)
{
dataTable.Columns.Add(new DataColumn(info.Name, Nullable.GetUnderlyingType(info.PropertyType) ?? info.PropertyType));
}
viewModel.GridTable = dataTable;
However, the key is making sure that the data returned from the AJAX read was a dataTable, not an IEnumerable type.
DataTable dataTable = ToDataTable<AssetLocationHistoryMetricData>(metricData);
var result = dataTable.ToDataSourceResult(request);
and this is what i used to convert the List to a dataTable
public static DataTable ToDataTable<T>(IEnumerable<T> items)
{
DataTable dataTable = new DataTable(typeof(T).Name);
//Get all the properties
PropertyInfo[] Props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
foreach (PropertyInfo prop in Props)
{
//Setting column names as Property names
dataTable.Columns.Add(prop.Name);
}
foreach (T item in items)
{
var values = new object[Props.Length];
for (int i = 0; i < Props.Length; i++)
{
//inserting property values to datatable rows
values[i] = Props[i].GetValue(item, null);
}
dataTable.Rows.Add(values);
}
//put a breakpoint here and check datatable
return dataTable;
}

Related

How should I pass my query from controller using ToPagedList

Actually i want to integrate paging in my view page and for that I am retrieving data from below code and I am passing this code from controller to view but any how I am facing issue as
var model = (from sr in db.StudentRequests
join c in db.Classes
on sr.ClassId equals c.ClassId
select new { sr.StudentRequestId,c.ClassName,sr.CreatedOn,sr.Location,sr.PaymentMethod }).ToList().ToPagedList(page ?? 1, 1);
return View(model);
and I am getting issue as
Type : InvalidOperationException
Message : The model item passed into the dictionary is of type 'PagedList.PagedList`1[<>f__AnonymousType3`5[System.Int32,System.String,System.Nullable`1[System.DateTime],System.String,System.String]]', but this dictionary requires a model item of type 'PagedList.IPagedList`1[Student_Tutor.Models.StudentRequest]'.
Source : System.Web.Mvc
My view side is as
#using PagedList;
#using PagedList.Mvc;
#model IPagedList<Student_Tutor.Models.StudentRequest>
#if (ViewBag.StudentRequest != null)
{
var StudentRequestId = (int)Model.First().StudentRequestId;// Here I am able to get the StudentRequestId
var StudentRequestTimecount = StudentRequestTime.Where(d => d.StudentRequestId == StudentRequestId).ToList();
var TutorStudentRequestcount = TutorStudentRequest.Where(d => d.StudentRequestId == StudentRequestId).ToList();
#Html.Displayfor(model => model.First().StudentRequestId)// here only text is displaying as StudentRequestId
#Html.Displayfor(Model => Model.First().CreatedOn)//here only text is diplaying as created on
}
please expalin why I am getting this error?
Update 1
var model = (from sr in db.StudentRequests
join c in db.Classes
on sr.ClassId equals c.ClassId
select new Studentvm{ StudentRequestId = sr.StudentRequestId,ClassName= c.ClassName,
CreatedOn =Convert.ToDateTime(sr.CreatedOn),Location= sr.Location,PaymentMethod= sr.PaymentMethod })
.ToList().ToPagedList(page ?? 1, 1);
return View(model);
but I am getting error as
An exception of type 'System.NotSupportedException' occurred in Student_Tutor.dll but was not handled in user code
Additional information: LINQ to Entities does not recognize the method 'System.DateTime ToDateTime(System.Object)' method, and this method cannot be translated into a store expression.
This part of your LINQ code
select new { sr.StudentRequestId,c.ClassName,sr.CreatedOn,sr.Location,sr.PaymentMethod }
That is creating an annonymous object for each item in the result collection you get from your LINQ query and you are creating a PagedList from that. But your view is strongly typed to PagedList<StudentRequest>
The ideal solution is to create a viewmodel to represent the data needed for this view and use that in the projection part of your LINQ query
public class StudentVm
{
public int StudentRequestId { set;get;}
public string ClassName { set;get;}
public DateTime CreatedOn { set;get;}
public string Location { set;get;}
}
Now use this view model for your projection
select new StudentVm { StudentRequestId = sr.StudentRequestId,
ClassName= c.ClassName,
Location = sr.Location,
CreatedOn = sr.CreatedOn }
And make sure your view is not strongly typed to PagedList<StudentVm>
#using PagedList;
#model PagedList<YourNamespace.StudentVm>
<table>
#foreach (var item in Model)
{
<tr>
<td>#Html.DisplayFor(a=> item.ClassName)</td>
<td>#Html.DisplayFor(a=> item.Location)</td>
<td>#Html.DisplayFor(a=> item.StudentRequestId)</td>
<td>#Html.DisplayFor(a=> item.CreatedOn)</td>
</tr>
}
</table>
Also, from your question, you are not really using the PagedList. To pass just a list of items, you do not need to convert that to PagedList<T> . You can simply send a List<StudentVm> from action method and change your view to be strongly typed to do that. Use PagedList if you are really using it (for paging)

An item with the same key has already been added when loading Kendo MVC Grid

I am trying to populate a Kendo mvcGrid and I keep getting the error An item with the same key has already been added.
I have seen elsewhere that duplicate model properties is the likeliest source of the problem but I have no duplicate properties in my model. I've even simplified everything to just a basic mock up to eliminate as many possible variables as possible..and I cant get the grid to load data.
I've tried it as a Html.Partial where its not loaded initially because of a empty model and then loading it through jquery...Ive tried with passing in am empty model so that the grid will load initially without data and then doing a datasource refresh...no luck there either. Basically as soon as I try to add content to the grid with a populated model I get the error and no data is loaded.
Been fighting this issue for 2 days now and had no luck. Ill post my code here maybe someone else can see what I'm missing.
One variable that cant change is the grid resides on a partial view with a model different from its parent view.
in the parent view I have tried both
<div id ="columnkgrid">#{Html.RenderPartial("Columns", new TestFieldIssue.Models.FieldListModel());}</div>
and
<div id="columnkgrid">#Html.Partial("Columns", new TestFieldIssue.Models.FieldListModel())</div>
either way will succeed in posting a grid with no data..it has no data yet because its populated by the selection of a value in a dropdown list.
so as to not over complicate the sample I've just set a hard coded value in the jquery function I have been using to refresh the grid.
function loadgrid() {
var grid = $("#grid").data("kendoGrid");
var val = 1;
grid.dataSource.read({ table_pk: val });
grid.refresh();
}
the grid code in the partial once again kept it simple without any bells and whistles just to test.
#(Html.Kendo().Grid(Model.fields)
.DataSource(data => data
.Ajax()
.Model(model => model.Id(m => m.field_pk))
.Read(r => r.Action("Columns","Home"))
)
.Name("grid")
.Columns(c =>
{
c.Bound(m => m.field_name).Title("Field Name").Width(100);
})
)
and the controller methods loading some mock data
public ActionResult Columns(int? table_pk)
{
FieldListModel model;
if (table_pk == null)
{
model = GetEmptyColumns();
}
else
{
model = GetColumns();
}
return PartialView("Columns", model);
}
public FieldListModel GetColumns()
{
FieldListModel model = new FieldListModel();
model.fields = new List<FieldModel>();
model.fields.Add(new FieldModel { field_name = "field1", field_pk = 1 });
model.fields.Add(new FieldModel { field_name = "field2", field_pk = 2 });
model.fields.Add(new FieldModel { field_name = "field3", field_pk = 3 });
return model;
}
public FieldListModel GetEmptyColumns()
{
FieldListModel model = new FieldListModel();
model.fields = new List<FieldModel>();
model.fields.Add(new FieldModel { field_name = "", field_pk = 0 });
return model;
}
and a very simple Model
public class FieldListModel
{
public List<FieldModel> fields { get; set; }
}
public class FieldModel
{
public int field_pk { get; set; }
public string field_name { get; set; }
}
I made few changes to run your code (correct version of Kendo and JQuery). May be those related to setup at my machine. I was able to reproduce the problem.
Then I changed the action code and was able to see the values populated in Grid:
public ActionResult Columns(int? table_pk, [DataSourceRequest] DataSourceRequest request)
{
FieldListModel model;
if (table_pk == null)
{
model = GetEmptyColumns();
}
else
{
model = GetColumns();
}
return Json(model.fields.ToDataSourceResult(request));
}
The change is accepting an additional parameter in action method of type DataSourceRequest. The Kendo grid wraps request in this object to specify sorting and paging information. The grid itself gets updated with data wrapped under DataSourceRequest object (note in return statement). More information here.

Kendo Grid has correct JSON but data not showing up

I'm trying to use Teleric's Kendo Grid in ASP.NET MVC 5. I'm following the example here, but the grid is not populating with data. The columns show up, but it says "No items to display".
http://docs.telerik.com/kendo-ui/getting-started/using-kendo-with/aspnet-mvc/helpers/grid/ajax-binding
This is my Words/Read function:
public ActionResult Read([DataSourceRequest] DataSourceRequest request)
{
var items = db.Words.Take(1).ToList();
//this code was necessary to get the correct JSON result
JsonSerializerSettings jsSettings = new JsonSerializerSettings();
jsSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
var converted = JsonConvert.SerializeObject(items, null, jsSettings);
return Content(converted);
}
I got the following JSON result from Words/Read:
[{"WordId":1,"Rank":1,"PartOfSpeech":"article","Image":"Upload/29/1/Capture1.PNG","FrequencyNumber":"22038615","Article":null,"ClarificationText":null,"WordName":"the | article","MasterId":0,"SoundFileUrl":"/UploadSound/7fd752a6-97ef-4a99-b324-a160295b8ac4/1/sixty_vocab_click_button.mp3","LangId":1,"CatId":null,"IsActive":false}]
Finally, my view page:
#(Html.Kendo().Grid<NextGen.Models.Word>
()
.Name("grid")
.DataSource(dataSource => dataSource
.Ajax()
.PageSize(15)
.Read(read => read.Action("Read", "Words"))
)
.Columns(columns =>
{
columns.Bound(c => c.WordName);
columns.Bound(c => c.PartOfSpeech);
})
.Pageable()
.Sortable()
)
I've seen some similar questions to this one, but most are using Javascript rather than Html helpers. Am I doing something dumb?
I found an alternative way to get around the circular reference problem I was having. Basically, the answer is here: A circular reference was detected while serializing an object of type 'SubSonic.Schema .DatabaseColumn'.
For people with the same problem: I took the two properties I needed - WordName and PartOfSpeech, and passed only those attributes to the toDataSource function Kendo provides.
My new read function looks like this:
public ActionResult Read([DataSourceRequest] DataSourceRequest request)
{
var items = db.Words.Select(w => new WordL{
WordName = w.WordName,
PartOfSpeech = w.PartOfSpeech
});
return Json(items.ToDataSourceResult(request));
}
where WordL is a model with just PartOfSpeech and WordName attributes, rather than all the attributes of my class.
It is probably because you are not using 2 methods in your controller. While your page view is first ActionResult you should use second one as in the grid as you did in your example. I hope it is obvious.
public ActionResult ReadPage()
{
return View();
}
public ActionResult Read([DataSourceRequest] DataSourceRequest request)
{
var items = db.Words.Take(1).ToList();
//this code was necessary to get the correct JSON result
JsonSerializerSettings jsSettings = new JsonSerializerSettings();
jsSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
var converted = JsonConvert.SerializeObject(items, null, jsSettings);
return Content(converted);
}

Auto-generate grid columns with collection of dynamic objects as model in Telerik MVC grid

My model is an IEnumerable which I would like to bind to a telerik mvc grid. Additionally the grid should auto-generate the columns and display everything from my dynamic object.
I found several posts on the telerik forum regarding this topic, like here: http://www.telerik.com/community/forums/aspnet-mvc/general/dynamically-generate-grid-columns.aspx
Unfortunately the result is the same: the grid displays the number of total rows in the footer but no rows are shown.
Any ideas?
Update: I attached a sample project on the telerik forum: http://www.telerik.com/community/forums/aspnet-mvc/grid/auto-generate-grid-columns-with-collection-of-dynamic-objects-as-model.aspx
Update: Here's sample code to try it out:
Index.cshtml:
#model IEnumerable<dynamic>
#(
Html.Telerik().Grid(Model).Name("Grid")
.Columns(columns => columns.AutoGenerate(true))
.Pageable()
.Sortable()
.Groupable()
.Filterable()
)
HomeController.cs:
public class HomeController : Controller
{
public ActionResult Index()
{
return View(GetStaticData());
}
private static IEnumerable<dynamic> GetStaticData()
{
dynamic products = new[]
{
new { ProductID = 1, ProductName = "Motor" },
new { ProductID = 2, ProductName = "Converter" },
new { ProductID = 3, ProductName = "Transformer" }
};
return products;
}
}
This post seems to say that it's not supported.
http://www.telerik.com/community/forums/aspnet-mvc/grid/display-dynamic-objects-in-grid.aspx
This post says that you can overload the columns binding and passing in the propery name.
http://www.telerik.com/community/forums/aspnet-mvc/grid/dynamic-view-with-grid.aspx
Looks like you can use dynamic data but not auto generated columns.
Thanks,

.net MVC, SelectLists, and LINQ

I am new to using the Html.DropDownList in the MVC framework and am having a hard time understading how to select the data out my database to bind to the DropDownList. Is there an easy way to return a bindable list (such as a SelectList) from a standard LINQ query?
The SelectList constructor takes an IEnumerable so all you need to do is pass the LINQ query to the constructor like so
var query = from c in customers
select c;
var customerList = new SelectList(query, "CustomerId", "CustomerName");
You should do this in the Controller and have the SelectList in your ViewModel.
You want to use the select keyword in the LINQ query:
var foo = new SelectList(from x in FooRepository.Items
select new SelectListItem { Text = x.Name, Value = x.Id });
var foo = FoorePository.Items.Select(s = > new SelectListItem
{
Text = s.Name, Value = s.Id.ToString()
}
);
Sorry about formatting.

Resources