Asp.net-mvc – ASP.NET MVC – using the same form to both create and edit

asp.net-mvcforms

Whats the best practice approach to creating a form that is used to both create new models and edit existing models?

Are there any tutorials that people can point me in the direction of?

Best Answer

NerdDinner will really show the way.

Create.aspx

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<NerdDinner.Models.Dinner>" MasterPageFile="~/Views/Shared/Site.Master"  %>
<asp:Content ID="Title" ContentPlaceHolderID="TitleContent" runat="server">
    Host a Nerd Dinner
</asp:Content>
<asp:Content ID="Create" ContentPlaceHolderID="MainContent" runat="server">
    <h2>Host a Dinner</h2>
    <% Html.RenderPartial("DinnerForm"); %>
</asp:Content>

Edit.aspx

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<NerdDinner.Models.Dinner>"
    MasterPageFile="~/Views/Shared/Site.Master" %>
<asp:Content ID="Title" ContentPlaceHolderID="TitleContent" runat="server">
    Edit: <%:Model.Title %>
</asp:Content>
<asp:Content ID="Edit" ContentPlaceHolderID="MainContent" runat="server">
    <h2>Edit Dinner</h2>
    <% Html.RenderPartial("DinnerForm"); %>
</asp:Content>

DinnerForm.ascx

<%@ Language="C#" Inherits="System.Web.Mvc.ViewUserControl<NerdDinner.Models.Dinner>" %>
<script src="/Scripts/MicrosoftAjax.js" type="text/javascript"></script>
<script src="/Scripts/MicrosoftMvcAjax.js" type="text/javascript"></script>
<script src="/Scripts/MicrosoftMvcValidation.js" type="text/javascript"></script>
<% Html.EnableClientValidation(); %>
<%: Html.ValidationSummary("Please correct the errors and try again.") %>
   <% using (Html.BeginForm())
      { %>
   <fieldset>
       <div id="dinnerDiv">
           <%:Html.EditorForModel() %>
           <p>
               <input type="submit" value="Save" />
           </p>
       </div>
       <div id="mapDiv">
           <%: Html.EditorFor(m => m.Location) %>
       </div>
   </fieldset>
   <% } %>

Take into account that this form is using Html.EditorForModel(), which is an innovative method for generating all the fields at once, and you have to study its disadvantages before using it. But you can easily take the rest of the example to separate your common form from the create and edit views.

Finally you can view the controller code here if you are interested.

Related Solutions

Jquery – How to post an array of string to ASP.NET MVC Controller without a form

I modified my response to include the code for a test app I did.

Update: I have updated the jQuery to set the 'traditional' setting to true so this will work again (per @DustinDavis' answer).

First the javascript:

function test()
{
    var stringArray = new Array();
    stringArray[0] = "item1";
    stringArray[1] = "item2";
    stringArray[2] = "item3";
    var postData = { values: stringArray };

    $.ajax({
        type: "POST",
        url: "/Home/SaveList",
        data: postData,
        success: function(data){
            alert(data.Result);
        },
        dataType: "json",
        traditional: true
    });
}

And here's the code in my controller class:

public JsonResult SaveList(List<String> values)
{
    return Json(new { Result = String.Format("Fist item in list: '{0}'", values[0]) });
}

When I call that javascript function, I get an alert saying "First item in list: 'item1'". Hope this helps!

In a Django form, how to make a field readonly (or disabled) so that it cannot be edited

As pointed out in this answer, Django 1.9 added the Field.disabled attribute:

The disabled boolean argument, when set to True, disables a form field using the disabled HTML attribute so that it won’t be editable by users. Even if a user tampers with the field’s value submitted to the server, it will be ignored in favor of the value from the form’s initial data.

With Django 1.8 and earlier, to disable entry on the widget and prevent malicious POST hacks you must scrub the input in addition to setting the readonly attribute on the form field:

class ItemForm(ModelForm):
    def __init__(self, *args, **kwargs):
        super(ItemForm, self).__init__(*args, **kwargs)
        instance = getattr(self, 'instance', None)
        if instance and instance.pk:
            self.fields['sku'].widget.attrs['readonly'] = True

    def clean_sku(self):
        instance = getattr(self, 'instance', None)
        if instance and instance.pk:
            return instance.sku
        else:
            return self.cleaned_data['sku']

Or, replace if instance and instance.pk with another condition indicating you're editing. You could also set the attribute disabled on the input field, instead of readonly.

The clean_sku function will ensure that the readonly value won't be overridden by a POST.

Otherwise, there is no built-in Django form field which will render a value while rejecting bound input data. If this is what you desire, you should instead create a separate ModelForm that excludes the uneditable field(s), and just print them inside your template.