I have a update controller action which is invoked when the form is posted.
In the form there is a radio button that controls the visibility of a drop down field
If drop down field is visible and I post the form, database is updated fine and ModelState is valid.
When the drop down field hidden and I post the form, it posts and updates the database.
But the ModelState.IsValid = false and the drop down is being reported as Missing value.
How to fix this issue?
[HttpPost]
public ActionResult Update(ResponseModel model)
{
//ModelState.IsValid = false when dropdown field hidden
//validate form fields
//update database
//if we are here, then db update successful
AjaxResponse.AddJsonItem("msg", "Success");
return Result();
}
It could be that your ResponseModel has a property annotated with some data annotation like [Required] and when you uncheck your radio box that property doesn't get a value.
Post your model and post the values you receive when state is invalid (By checking in debugger).
Since you only have one property and that is integer. Your model state is invalid because integer can not have null value. When you make it hidden the model doesn't have value for the int property. Either replace the dropdown with hidden field on radio box or make it a nullable int.
Related
I am developing an application where I have a form with a model "StudentListModel".
I have a button in the same page which is not a submit button. I have written an ajax function which calls an action method in the controller specified.
Now my problem is there is a textbox for the studentname ,
[StringLength(160, MinimumLength = 3)]
[Display(Name = "First Name")]
[Required]
[Remote("CheckDuplicateNames", "AddStudent")]
public string StudentName { get; set; }
None of these validations are firing.However if I make the button as submit ,these will work.
Is there any way to do model validation other than using formsubmission?
Model validation is done automatically before your ActionMethod is executed and ModelState will be populated with information about that validation. You do not need to call ValidateModel as long as you are running your Controller and ActionMethods in the default MVC lifecycle.
An action method that has parameters will have the values for parameters populated using MVC Model Binding. This means that any values posted in a Form or QueryString (and a few other sources) will be name matched to simple parameters or properties in complex parameters. Using an HTML form and the MVC HtmlHelper methods for creating input types you get the desired behavior with very little work, but as you have noted it requires a form submit to send the data.
An ajax call will also populate the model using Model Binding but it requires the fields to be sent to the ActionMethod. Using jQuery it is as simple as performing a post or get request on the buttons click event passing a JavaScript object with your model's properties on it.
$('#yourButtonId').click(function() {
var student = {};
student.StudentName = $('#StudentName').val();
$.post('#Url.Action("ActionMethodName")', student).done(function (data) {
//handle returned result from ActionMethod}
});
});
You can call model validation manually in the controller method. The syntax is simply ValidateModel(model). This validates the model based on its current property values, and populates the ModelState dictionary with any errors.
If your model does not get populated with the values, but you have got them at hand, you can populate it using UpdateModel(model, values), another method inherited from the Controller class.
I am reading an enum value from the db then bind it to the model. When i post the form with ajax, somehow the enum is unbound or the model property in null or zero but it display properly on the view. I have posted code below. Im using entityframework and mvc3
//model code constructor
public CarModel(Car car)
{
State=(CarState)car.State;
//car.State comes in as an int
//etc setting other variables
}
//CarState property
public CarState {get;set;}
//model code
#Html.DisplayFor(m=>m.CarState)
//Controller code()
Save(CarModel car)
{
//I have code that saves the changes
}
The minute i get to "car", CarState has no value.
It's not quite clear how you are passing this value to the controller action. You have only shown some #Html.DisplayFor(m=>m.CarState) but obviously this only displays a label in the view. It doesn't send anything back to the server. If you want to send some value back you will have to use an input field inside the form.
For example:
#Html.EditorFor(m => m.CarState)
or use a HiddenFor field if you don't want the user to edit it.
In any case you need to send that value to the server if you expect the model binder to be able to retrieve it. The model binder is not a magician. He cannot invent values. He binds values to your model from the Request.
I am still learning MVC3 and Razor, so this is perhaps a simple question.
On a view I have a DropDownList whose sole purpose is to help filter (via AJAX) a second drop down list:
#Html.DropDownList("Segments", "-- select segment --")
There is a Segments property of the ViewModel that is defined as:
public IEnumerable<SelectListItem> Segments { get; set; }
There is JavaScript that handles the change event for this DropDownList and populates another DropDownList with appropriate values. That other DropDownList is defined like this:
#Html.DropDownListFor(m => m.fafhProdRecId, Enumerable.Empty<SelectListItem>(), "-- select product recommendation --")
This all works fine until I submit. When I submit, I get a validation error on the Segments drop down list!
Now -- there should be absolutely NO validation on the segments DropDownList -- there shouldn't be any client side validation on EITHER drop down list, for that matter.
But when I try to submit, I get the validation error message back:
The value '1' is invalid.
I have no idea why this is happening.
I have no idea how to decorate the Segments property to say that it is NOT required.
I have no idea how to tell the unobtrusive javascript validator that it is, in fact, being quite obtrusive.
In your ViewModel class add [Bind(Exclude = "Segments")]
From: Using Data Annotations for Model Validation
make sure that your Model has fafhProdRecId as nullable, I imagine it's declared as:
public int fafhProdRecId { get; set; }
change this to:
public int? fafhProdRecId { get; set; }
hopefully, that should resolve the issue as this effectively makes the model field nullable (assuming the db field IS nullable too of course).
I am somewhat new to MVC 3 so this could be something simple. I have a Compact SQL 4 database. There is a Post object that has a Contents (string), Subject (string), When (DateTime) and Reposted (DateTime nullable) fields. During the Create's Post method, I manually force the When property to be DateTime.Now and it works great.
However, on my Edit View, I do NOT want to show this field or at least not let it be an editable field. When I do NOT put it as an editable field on the Edit View and they change say the Contents and then click Save I get the message:
An overflow occurred while converting to datetime.
During the Edit Postback, I am setting the Reposted field to DateTime.Now so it has to be the When field. When I debug on that postback I see that the "Post" object is only filled in with values of the fields I am displaying on the screen. So I decided to just grab the When field out with a LINQ query directly from the data but when I get to the SaveChanges it fails and says the following:
An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key
So how can I update an object and let the user only change a few pertinant fields? Seems like the Post object is not getting ALL of the existing values since they are not showing on the screen. How can I fill that object completely?
Edit: Here is the Post method.
[HttpPost]
public ActionResult Edit(Post post) {
if (ModelState.IsValid) {
db.Posts.Attach(post);
int Successes = 0;
int Failures = 0;
this.SendEMail(post, out Successes, out Failures);
post.Successes = Successes;
post.Failures = Failures;
post.Reposted = DateTime.Now;
db.ObjectStateManager.ChangeObjectState(post, EntityState.Modified);
db.SaveChanges();
return RedirectToAction("Index");
}
return View(post);
}
Include a hidden field in your view for the fields that you do not want to display e.g.
#Html.HiddenFor(model => model.When)
So I have a jqGrid on an ASP.NET MVC 3 website. It's loading the data, searching, filtering, and saving rows with the built in pop-up editor. What I can't get to work is saving a nullable property. I'm using LargeJsonResult instead of the built in JsonResult, so an example of a row in the grid is this:
// C# class
public class Row
{
public string A { get; set; }
public string B { get; set; }
public int C { get; set; }
}
// an example object instance, let's say these values come from the DB
var ret = new Row { A = "a", B = null, C = 5 };
// the JSON string sent to the grid will look like this (notice B is omitted)
// "{ A: 'a', C: 5 }"
Now, the grid will show this as:
A B C
a undefined 5
And this brings me to my problem. The pop-up edit form will show "undefined" in the textbox for B, and will also post this to the server. So if I save that to the database, I'll have "undefined" in my DB instead of null.
How do I get jqGrid to preserve the null value round trip? One solution that seems to me very hacky is based on something Oleg solved in another thread:
// override jqGrid serialization
jQuery.extend(jQuery.jgrid.edit, { ajaxEditOptions: { contentType: "application/json" }, serializeEditData: function (data) {
return JSON.stringify(data).replace(/"undefined"/g, 'null');
}});
This will work, but seems dangerous because it's doing mass edits of data without the user's knowledge. In thinking more about it, I guess this is the fundamental problem of saving back null instead of "undefined" or some other string representation of null (empty string, etc.). The desired behavior would be:
if the property is null, and the user doesn't change the value, it posts as null
if the user changes the value, the property is no longer null
Can we get the grid's edit form to behave like this for nullable properties? Or would I have to create a custom edit form that tracks what the user does with a property?
I hope that I understand your problem. In one my applications where I used jqGrid I had once the problem with NULL values. At the time of development of the application I was not sure how to solve the problem and I placed on the server side the text value "(NULL)" instead of null value of one property. The grid was for advanced users who understand what "(NULL)" is. The value "(NULL)" has no sense in the field (one had no user account with the name) and inside of server code for the Edit operation I could distinguish "(NULL)" value from the real field value. In the way I could come over the problem.
In your case you should solve at least two problems:
You should decide how the null value should be displayed. The "undefined" text seems me not the best one. You can solve the problem with the "undefined" text either on the server side (like I did in my case) or with respect of custom formatter. The custom formatter is very simple thing. It define how a cell value should be displayed as a HTML fragment of the <td> contain. You can for example include an additional hidden <span> element or other HTML element or attribute which will save the information that the value was null.
You should solve the problem with decoding of the null value on the server side during Edit operations. You can solve the problem very easy on the server side (like I do with compare of the corresponding field to the "(NULL)") or with respect of custom unformatter on the client side. The custom unformatter will get the information from the grid cell (from the hidden <span> or other hidden HTML element or attribute) and place the information in the server request.
You can look at the demo for the answer to see an example how one can use a hidden <span> to save an additional information in the cell with respect of custom formatter and to read the information later with respect of custom unformatter.