I have a form:
#using (Html.BeginForm("QuoteUpdate", "Home", FormMethod.Post))
{
#Html.DropDownList("network", Model.availableNetworks);
#Html.DropDownList("grade", Model.grades);
#Html.HiddenFor(o => o.Product.id);
<button type="submit">Get Quote</button>
}
And a controller:
[HttpPost]
public ActionResult QuoteUpdate(int? id, string network, string grade )
{
}
The id property is always null after form is submitted. I have checked source and the hidden field has the correct value in the rendered HTML.
I cannot figure out why this parameter is always null. What am I missing?
Since you're accessing a nested property on your model, the generated HTML is probably something like this:
<input type="hidden" id="Product_id" name="Product.id" />
When your form gets posted to the controller action, there's not a parameter that matches up with Product.Id.
You could work around this by changing the generated name of the input (see this answer for more about how to do that):
#Html.HiddenFor(o => o.Product.id, new { Name = "id" });
Which will generate:
<input type="hidden" id="Product_id" name="id" />
Then things should model bind correctly.
Related
I have model property int? CaseId
public class TaskDetailsVm
{
public TaskDetailsVm(Task task)
{
CaseId = task.CaseID;
}
public int? CaseId { get; set; }
}
and on view:
#Html.HiddenFor(x => x.CaseId) => 0
#Html.Hidden("CaseId", Model.CaseId) => 0
#Html.Hidden("qwe", Model.CaseId) => real value
<input type="hidden" id="CaseId" name="CaseId" value="#Model.CaseId" /> => real value
in browser I see this:
<input data-val="true" data-val-number="The field CaseId must be a number." id="CaseId" name="CaseId" type="hidden" value="0">
<input id="CaseId" name="CaseId" type="hidden" value="0">
<input id="qwe" name="qwe" type="hidden" value="22906">
<input type="hidden" id="CaseId" name="CaseId" value="22906">
Why can I see the following? I don't see any scripts to override this value. And how can I resolve it?
Also for first line of code I see additional attributes data-val="true" and data-val-number="The field CaseId must be a number." for some reasons that I can't understand.
This has to do with the ModelState. As per this article:
ASP.NET MVC assumes that if you’re rendering a View in response to an HTTP POST, and you’re using the Html Helpers, then you are most likely to be re-displaying a form that has failed validation. Therefore, the Html Helpers actually check in ModelState for the value to display in a field before they look in the Model. This enables them to redisplay erroneous data that was entered by the user, and a matching error message if needed. Since our [HttpPost] overload of Index relies on Model Binding to parse the POST data, ModelState has automatically been populated with the values of the fields. In our action we change the Model data (not the ModelState), but the Html Helpers (i.e. Html.Hidden and Html.TextBox) check ModelState first… and so display the values that were received by the action, not those we modified.
Now in this case: #Html.HiddenFor(x => x.CaseId, new {Value = #Model.CaseId}), since you are explicitly defining a value for the current Model, it displays the value that you expect. You can use ModelState.Clear(); in your Controller after your POST on the form to reset the model values.
I have a form with a DropDownListFor. When I select the ID from my drop down list, select a date and click submit, I get error:
The parameters dictionary contains a null entry for parameter 'CasinoID' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult Index(Int32, System.DateTime, NameSpace.ViewModels.TerminalReceiptPostData)' in 'Namesppace.Controllers.TerminalReceiptsController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
Parameter name: parameters
It worked fine with just a regular Input tag and typing it in manually... however when I added a DropDownListFor this issue arises. Am I setting up the DDL wrong? Any other issues as to why this would happen? Below is some code.
Controller Action:
[HttpPost]
public ActionResult Index(int CasinoID, DateTime Date)
{
var model = TRBL.GetTransactionTestsData(CasinoID, Date);
return View(model);
}
View:
#using (Html.BeginForm("Index", "TerminalReceipts", new { id = "submitForm" }))
{
<div>
#*<input type="text" name="CasinoID" placeholder="Enter Casino ID" id="cIdSearch" />*#
#Html.DropDownListFor(o => o.TerminalReceiptPostData.CasinoIdDDL, Model.TerminalReceiptPostData.CasinoIdDDL, new { id = "CasinoID"})
<input id="datepicker" class="datepicker-base" name="Date" placeholder="MM/DD/YYY" type="text" />
<button type="submit" class="btn btn-sm btn-primary" id="search" onclick="checkField()"> Search Transactions</button>
</div>
}
Edit update
So I was able to change how the structure a bit to now be able to get the CasinoID to be passed properly to the controller action. Below are the changes... however after the action goes to return the model, I get an obj reference not set to instance of the obj err.
Action:
[HttpPost]
public ActionResult Index(int CasinoID, DateTime Date)
{
var id = Int32.Parse(Request.Form["CasinoID"].ToString());
var model = TRBL.GetTransactionTestsData(id, Date);
return View(model);
}
Change to DDL:
#Html.DropDownList("CasinoID", Model.TerminalReceiptPostData.CasinoIdDDL, "Select Casino")
The int CasinoID will be bound by a form field with the name CasinoID. I think the #Html.DropDownListFor is not generating the 'name' you want.
You can add name explicitly like
#Html.DropDownListFor(o => o.TerminalReceiptPostData.CasinoIdDDL, Model.TerminalReceiptPostData.CasinoIdDDL, new { id = "CasinoID", name="CasinoID"})
Or better to create a ViewModel with the fields CasinoID, Date & CId and use BindProperty on that ViewModel instance
Okay so I figured out what was going on..
I actually have two seperate controller actions named Index. One for post and one for get. Since I am now sending back a model on the POST one, the drop down list was not getting "re-filled" with the drop downs... So i simply took a call from my GET action and added it to the post..
[HttpPost]
public ActionResult Index(int CasinoID, DateTime Date)
{
var id = Int32.Parse(Request.Form["CasinoID"].ToString());
var model = TRBL.GetTransactionTestsData(id, Date);
model.TerminalReceiptPostData = TRBL.GetCasinosDDL();
return View(model);
}
Probably not the best way to do it, but works fine.
In my [HttpGet] Create Action I have this:
public ActionResult Create(int? id)
{
ViewBag.TestTypeID = new SelectList(db.codeTypes, "ID", "TestType");
OHealth oHealth = new OHealth();
oHealth.OID = Convert.ToInt32(id);
oHealth.DateEntered = DateTime.Today;
return View(oHealth);
}
Now, OID is a foreign key, not the primary key ID. As you can see I don't assign ID any value.. only OID. ID is auto-incremented in the database.
Here is how my HTML renders for my Create View for OID and ID:
<input data-val="true" data-val-number="The field ID must be a number." data-val-required="The ID field is required." id="ID" name="ID" type="hidden" value="2" />
<input data-val="true" data-val-number="The field OID must be a number." data-val-required="The OID field is required." id="OID" name="OID" type="hidden" value="2" />
So when I hit create, the ID field is given the value of 2 when it should be 1 since it will be the first record in the database.
How is my ID field receiving a value of 2 when that hasn't been assigned?
Let me know if more is needed.
Any help is appreciated.
UPDATE
Razor for those 2 fields:
#Html.HiddenFor(model => model.ID)
#Html.HiddenFor(model => model.OID)
MVC automatically binds parameters into the modelstate. So your parameter id in:
public ActionResult Create(int? id)
will be automatically put into Model.ID (as url params are case-insensitive).
You should be able to confirm this by changing the name of the parameter (and corresponding url/action definition), eg:
public ActionResult Create(int? anotherid)
and change the url from /Create/2 to /Create?anotherid=2
This occurs automatically so that any values in a POST will automatically have the same values they had when the form was posted without you needing to explicitly set them. In a GET this occurs from the parameters.
The fix is to add ModelState.Clear():
public ActionResult Create(int? id)
{
if (!ModelState.IsValid) return;
ModelState.Clear();
this will stop the auto-rebinding when the view fields are regenerated.
The re-binding occurs after the view has been generated, all the field values are re-inserted from ModelState. By clearing modelstate, you stop this from happening.
Im playing around with a booking-system in MVC.
I have a view where you select 3 diffrent values (treatment, hairdresser and date).
#using (Html.BeginForm("testing", "Home", FormMethod.Post)) {
<p id="frisor"> Frisör: #Html.DropDownList("Fris", "All")<a class="butt" onclick="showdiv()">Nästa steg</a></p>
<p id="behandling">Behandling: #Html.DropDownList("Cat", "All")<a class="butt" onclick="showdiv2()">Nästa steg</a></p>
<p>
Datum:
<input type="text" id="MyDate" /> <-------This is a jquery datetimepicker
</p
I would like to save the customers three choices in three properties i have created.
My post method looks like this:
[HttpPost]
public ActionResult Testing(string Fris, string Cat, DateTime MyDate)
{
kv.treatment = Cat
kv.Hairdresser = Fris;
kv.Datum = MyDate;
return View();
}
I get the two first (hairdresser,treatment) fine,
the problem is that i dont know how to get the value from the jquery datetimpicker.
Any help appreciated!
The input needs a name in order to be included in the form post:
<input type="text" id="MyDate" name="MyDate" />
Otherwise the browser won't include it in the posted data, so it will never reach the server for model binding. (And, of course, the name has to match the method argument name for the model binder to match them.)
I have a model with one of the property of type object . This property is a dynamic property and could sometime contain a string or a date or a Boolean.
I have a editor template for each type i.e boolean , string , date etc .
The problem I have is when the page is posted , the postback contains a array instead of the actual value. The first element of the array contains the actual value.
Why is the value being returned as a array ?
My model
public string Description;
public string Name { get; set; }
public Type Type{ get; set; }
object _value;
public object Value { get;set;}
statement in the view
#Html.EditorFor( m => m.Value)
Edit : Corrected the object name from _value to Value. It was a wrong Ctrl V operation.
Edit : The HTML rendered in the browser
When the object contain a boolean value (checkbox):
<div>
<input checked="checked" data-val="true" data-val-required="The BoolJPY field is required." id="FurtherInformationFieldObject_Properties_1__Value" name="FurtherInformationFieldObject.Properties[1].Value" type="checkbox" value="true"><input name="FurtherInformationFieldObject.Properties[1].Value" type="hidden" value="false">
When the object contains a string(Textbox) :
<div id="divStringField"><input class="text-box single-line valid" data-val="true" data-val-required="The String Field field is required." id="FurtherInformationFieldObject_Properties_2__Value" name="FurtherInformationFieldObject.Properties[2].Value" type="text" value=""> </div>
Edit 2 : Posting the complete model and view code.
Controller code :
public ActionResult Edit(string name ="field1" )
{
Models.DynamicData data1 = new Models.DynamicData();
//all this comes from the database table. I am putting the value directly in field just for simplicity
// this is exactly how I convert the value from the entity to the model
data1.Description = "Field1 Description";
data1.Name = "field1";
data1.Type = typeof(string);
data1.Value = Convert.ChangeType("MyStringValue", data1.Type);
//similarly add few more fields to the model collection
return View(data1);
}
[HttpPost]
public ActionResult Edit(Models.DynamicData model)
{
// break point here : model.Value shows a array of string instead of the edited value.
return View(model);
}
View :
#model SampleDynamicDataProject.Models.DynamicData
#{
ViewBag.Title = "Edit";
}
<h2>Edit</h2>
#using (Html.BeginForm()) {
#Html.AntiForgeryToken()
#Html.ValidationSummary(true)
<fieldset>
<legend>DynamicData</legend>
<div class="editor-label">
#Model.Description
</div>
<div class="editor-field">
#Html.EditorFor(model => model.Value)
#Html.ValidationMessageFor(model => model.Value)
</div>
<p>
<input type="submit" value="Save" />
</p>
</fieldset>
}
I should explain I used object as type for Value property because the value could be string or bool or date ex data1 in above controller could look like below
data1.Description = "Field2 Description";
data1.Name = "field2";
data1.Type = typeof(bool);
data1.Value = Convert.ChangeType("true", data1.Type); // database stores "true" as string which is converted into a boolean and stored in the object.
As shown in the code , my problem is in the post action for Edit , I get Value as an array even for a simple string.
The sample project code here https://drive.google.com/file/d/0B3xCaeRk2IQZSTM0aHdoWEtNYW8/edit?usp=sharing
I got a answer to my question at one of the other forums.
Basically the reason MVC binder is returning a array is because it does not understand what type of data/control is used in the html and the model binder fails.
I got around my issue by modifying the model to have two different property a
public String StringValue
public Bool BooleanValue
I use the StringValue field when the Type is String , Date , Number etc.
I use the BooleanValue for field with Type as Boolean.
Its not the cleanest approach but it will have to do till the point I write my own custom model binder.
Thanks to bruce who answered my question here http://forums.asp.net/p/1961776/5605374.aspx?Re+MVC+4+Postback+returns+a+array+for+property+of+type+object+in+my+model
I now understand why the model binder fails.
Pasting his answer here for the benefit of others
you need to understand how browser postback is done. on form submit a collection of name/value pairs is sent. the name is the form element name, the value is the elements value. standard url encoding is done. so for:
the postdata is
foo=1&bar=true
note the post data is just a string with no type data. the brwser allows duplicate name, so
the post data is:
foo=1&foo=true
when asp.net load the post data into the form collection (which is just a dictionary), it can not add the key "foo" twice, but concats the values seperated by a "," ("1,true"). the binder just treats it as a string array named foo with 2 values.
now we get to another browser behavior. form elements that support checked (radio and checkbox) are only include the post data if checked. this causes a problem for the mvc binder with checkbox, becuase it can not tell from the postback data if the element was not checked or not included. this is important if you are using tryupdate to apply only a subset of the model properties, becuase only a subset was rendered. to get around this, the checkbox helper renders two fields with the same name, a hidden with the value "false" and a checkbox with the value "true".