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ValidationSummary

in namespace DotVVM.Framework.Controls

Displays all validation messages from the current Validation.Target.

Usage & Scenarios

Displays all validation errors in a list.

Look at the Validation tutorial to see how the validation works.

Sample 1: Basic ValidationSummary

The ValidationSummary will display all validation errors in the validation context.

page.dothtml
ViewModel.cs

<dot:TextBox Text="{value: Text}" />

<dot:ValidationSummary />

<dot:Button Text="SEND" Click="{command: Send()}" />

using System.ComponentModel.DataAnnotations;

namespace DotvvmWeb.Views.Docs.Controls.builtin.ValidationSummary.sample1
{
    public class ViewModel
    {
        [Required]
        public string Text { get; set; }

        public void Send()
        {
            // process data
        }
    }
}

Sample 2: Validation errors from child objects

By default, the ValidationSummary control displays errors that comes directly from the Validation.Target object's properties. If the validation target contains another child objects, the validation errors from those objects are not displayed. This is because of performance reasons.

However, using the IncludeErrorsFromChildren property, you can tell the control to display validation errors event from the child objects. Just be careful because there will be a performance penalty if you use this feature on large and complicated viewmodels.

page.dothtml
ViewModel.cs

<dot:TextBox Text="{value: ChildObject.Text}" />

<dot:ValidationSummary IncludeErrorsFromChildren="true" />

<dot:Button Text="SEND" Click="{command: Send()}" />

using System.ComponentModel.DataAnnotations;

namespace DotvvmWeb.Views.Docs.Controls.builtin.ValidationSummary.sample2
{
    public class ViewModel
    {
        public ChildViewModel ChildObject { get; set; } = new ChildViewModel();

        public void Send()
        {
            // process data
        }
    }

    public class ChildViewModel
    {
        [Required]
        public string Text { get; set; }
    }
}

Sample 3: Validation errors from the `Validation.Target`

The ValidationSummary control also displays validation errors attached directly to the Validation.Target object. This is useful for errors which do not belong to a particular property (for example, incorrect username or password).

You can disable the behavior by setting the IncludeErrorsFromTarget property to false.

The sample below creates a server-side validation error using the IValidatableObject interface.

The default value of the IncludeErrorsFromTarget property was changed in DotVVM 4.0 - previously, it was false. In DotVVM 4.0, we've decided to change this to true as it is a more reasonable default value.

page.dothtml
ViewModel.cs

<dot:TextBox Text="{value: ChildObject.Text1}" />
<dot:TextBox Text="{value: ChildObject.Text2}" />

<dot:ValidationSummary 
    Validation.Target="{value: ChildObject}"/>

<dot:Button Text="SEND" Click="{command: Send()}" />

using DotVVM.Framework.ViewModel;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace DotvvmWeb.Views.Docs.Controls.builtin.ValidationSummary.sample3
{
    public class ViewModel
    {
        public ChildViewModel ChildObject { get; set; } = new ChildViewModel();

        public void Send()
        {
            // process data
        }
    }

    public class ChildViewModel : IValidatableObject
    {
        [Required]
        public string Text1 { get; set; }

        [Required]
        public string Text2 { get; set; }

        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
        {
            if (Text1 != Text2)
            {
                yield return new ValidationResult("This ChildViewModel is not valid.");
            }
        }
    }
}

Show all inherited properties

Properties

Name	Type	Description	Notes	Default Value
ClientIDMode	ClientIDMode	Gets or sets the client ID generation algorithm.	attribute inner element static value bindable default	Static
DataContext	Object	Gets or sets a data context for the control and its children. All value and command bindings are evaluated in context of this value. The DataContext is null in client-side templates.	attribute inner element static value bindable default	null
HideWhenValid	Boolean	Gets or sets whether this control is hidden if there are no validation messages	attribute inner element static value bindable default	False
ID	String	Gets or sets the control client ID within its naming container.	attribute inner element static value bindable default	null
IncludeErrorsFromChildren	Boolean	Gets or sets whether the errors from child objects in the viewmodel will be displayed too.	attribute inner element static value bindable default	False
IncludeErrorsFromTarget	Boolean	Gets or sets whether the errors from the TargetProperty object will be displayed too.	attribute inner element static value bindable default	True
IncludeInPage	Boolean	Gets or sets whether the control is included in the DOM of the page.	attribute inner element static value bindable default	True
InnerText	String	Gets or sets the inner text of the HTML element. Note that this property can only be used on HtmlGenericControl directly and when the control does not have any children.	attribute inner element static value bindable default	null
Visible	Boolean	Gets or sets whether the control is visible. When set to false, `style="display: none"` will be added to this control.	attribute inner element static value bindable default	True

HTML produced by the control

This control renders the HTML unordered list.

<ul data-bind="foreach: ...">
  <li data-bind="..."></li>
</ul>